IBM SYSTEM/370 MUSIC KERMIT USER'S GUIDE
VERSION 4.3
John Chandler
Harvard/Smithsonian Center for Astrophysics
September 30, 1993
Copyright (C) 1981,1993
Trustees of Columbia University in the City of New York
Permission is granted to any individual or institution to use, copy,
or redistribute this document so long as it is not sold for profit, and
provided this copyright notice is retained.
Table of Contents
1. IBM 370 KERMIT 1
1.1. Translation Tables 1
1.2. File Attributes 2
1.3. Program Operation 2
1.4. Kermit-370 Subcommands 3
1.5. Before Connecting to the Mainframe 9
1.6. Trouble-shooting Protocol Converters 9
1.7. After Returning from Kermit-370 10
1.8. What's New 10
1.9. What's Missing 11
1.10. Further Reading 11
2. IBM MUSIC/SP KERMIT 12
2.1. The MUSIC/SP File System 12
2.2. Program Operation 12
2.3. Kermit-MUSIC Subcommands 13
2.4. How to build an executable version of Kermit-MUSIC 13
2.5. What's New 14
2.6. What's Missing 14
Index 15
List of Tables
Table 1-1: Allowed character set combinations in Kermit-370 1
Table 1-2: EBCDIC (hexadecimal) code points for LATIN1 2
Table 1-3: Character graphics for EBCDIC codes 2
Table 1-4: Error messages and codes for Kermit-370 11
1. IBM 370 KERMIT
Program: John Chandler (Harvard/Smithsonian Center for Astrophysics);
contributions from Vace Kundakci and Daphne Tzoar (Columbia U),
Bob Shields (U. Maryland), Greg Small (UC Berkeley), Clark
Frazier (Harvard Bus. Sch.), Bob Bolch and Steve Blankinship
(Triangle), Ron Rusnak (U. Chicago), Roger Fajman and Dale
Wright (NIH), Andre Pirard (U. Liege), Pierre Goyette (McGill
U.)
Language: IBM 370 Assembler
Documentation: John Chandler (CfA)
Version: 4.3
Date: 1993 September
Kermit-370 is a family of programs implementing the KERMIT file transfer
protocol for IBM 370-series mainframes (System/370, 303x, 43xx, 308x, 3090,
etc.) under a variety of operating systems. Kermit-370 operates over
asynchronous ASCII communication lines attached to a 3705-style or protocol en-
veloping 3708 front end ("TTY" or line-mode devices), to a Series/1 or 4994
running the Yale ASCII Terminal Communication System or the IBM 7171 ASCII
Device Control Unit or a 9370 with ASCII subsystem ("SERIES1" devices), to the
IBM 3174 protocol converter at level B2.0 or higher ("AEA" devices), or to
front-ends with graphics pass-through mode, such as the Datastream/Leedata 8010
and PCI 1076 ("GRAPHICS" devices). As of this writing, the pending implemen-
tation of full(er) 7171 compatibility in the program product SIM3278 has not
been completed. The non-line-mode devices are often called full-screen
devices. For more details on front ends, see the section SET CONTROLLER.
The source is coded in IBM 370 assembly language and is compatible with the F,
VS, and H assemblers. The code is divided into sections, some generic and some
specific to an individual operating system. While the details of file-system
and supervisor interaction vary widely among the systems available for IBM
370's, the basic features are essentially the same. This chapter describes the
features common to all variants of Kermit-370, and a separate chapter will deal
with the system-specific details for each variant.
IBM 370 systems have some peculiarities that users should be aware of. First,
these systems are essentially half-duplex; the communication line must "turn
around" before any data can be sent. The "TTY" devices are strictly
half-duplex, and even the "SERIES1", "GRAPHICS", and "AEA" devices, although
they maintain full-duplex communication with the terminal, must transmit a
block at a time to the mainframe. The fact that a packet has been received
from the IBM system through a "TTY" device is no guarantee that it is ready for
a reply; generally, the true indicator of readiness is the line turnaround
character (XON), which the operating system sends immediately before issuing a
read request. On some systems, however, it is possible for Kermit to do away
with the system-supplied turnaround and schedule read requests immediately
after the corresponding writes. It is up to the user to tell the other Kermit
how it must conform to the requirements of the IBM mainframe.
A second distinction is that disk files are encoded using the EBCDIC character
set. Consequently, there are three layers of character translation on packets
exchanged on a "TTY" device. For an incoming packet, the outer layer is
provided by the operating system, which translates all characters from ASCII to
EBCDIC. Kermit-370 must then translate the packets back to ASCII (the middle
layer) in order to calculate and verify the checksum. Data arriving through a
"SERIES1", "GRAPHICS", or "AEA" device are still in ASCII and therefore bypass
the two outer layers. In any case, Kermit-370 translates text files finally
into EBCDIC (the inner layer) before storing on disk. When Kermit-370 sends a
file, the opposite translations occur. The middle-layer tables used by Kermit
must be the inverses of the corresponding outer-layer ones used by the host
operating system if file transfers are to work at all. If necessary, the sys-
tem programmer should add the appropriate SET TATOE/TETOA/TTABLE subcommands
(q.v.) to the global INIT file. Indeed, it is usually a good idea to set
TTABLE ON in the global INIT file to force using different built-in sets of
tables for the inner and middle layers whenever the system has "TTY" devices.
The standard 7-bit ASCII-to-EBCDIC translations can be found in the Appendix or
the IBM System/370 Reference Card. See the section "Translation Tables" for
more details.
Another distinction of IBM 370's is that they store and retrieve files as
records rather than byte streams. Records may be either fixed-length with some
sort of padding (as needed) or varying-length with some sort of (generally hid-
den) delimiters. Thus, Kermit-370 must assemble incoming data packets into
records by stripping off carriage return-linefeed pairs (CRLF's) and padding
with blanks or truncating as needed and must strip trailing blanks and append
CRLF's to outgoing records. (See the SET FILE TYPE subcommand.) Further, disk
files typically have the records combined into blocks for efficiency. One con-
sequence of this form of storage is that files have attributes describing the
component records: maximum record length (LRECL), record format (RECFM), and
sometimes block size (BLKSIZE).
As mentioned before, Kermit-370 is a family of programs. At present, only the
CMS, TSO, MUSIC, ROSCOE, and CICS variants are operational. Variants for DOS-4
and MTS have at least reached the "drawing board," but no others have even been
started as of this writing. Volunteers are always welcome to port Kermit-370
to other operating systems or add new features to the existing family. Anyone
interested should first get in touch with the Center for Computing Activities
at Columbia University to find out what projects of a similar nature are al-
ready pending (and thereby prevent unnecessary duplication of effort). There
are supplemental files in the Kermit distribution with explanations of how to
go about porting Kermit-370 and how to add support for new terminal controller
types. For details, refer to the installation guide for the variant of your
choice.
1.1. Translation Tables
Traditionally, IBM mainframe Kermits have translated 7-bit ASCII characters to
8-bit EBCDIC characters and ignored the "parity" bit in the process.
Similarly, the 8-bit EBCDIC characters have been mapped onto 7-bit ASCII,
thereby producing many ambiguities in translating the ASCII files back to
EBCDIC. These ambiguities fall into two categories: EBCDIC characters not
representable in ASCII have been rendered as ASCII nulls, and alternate EBCDIC
representations of characters such as the ASCII backslash have been mapped
together, but at least no two 7-bit ASCII characters are translated into the
same EBCDIC character. The ambiguities were tolerable in environments where
the traditionally non-printable characters never occurred in text files, but
text processing has increasingly tended to include such characters for math-
ematical formulas or for languages other than English. Ultimately, the trans-
lation tables must become completely invertible, lest information be lost in
the transfer. There has long been an option to replace parts of the trans-
lation tables via commands from the user (or imbedded in the INIT files), but
such replacements were always supported locally and were, therefore, basically
non-standard.
The concept of standard translations is currently in a state of flux because of
the proliferation of 8-bit code pages and the countervailing efforts at stan-
dardization among groups such as the ISO and Kermit developers. In particular,
Kermit-370 now supports a set of EBCDIC and "extended ASCII" code pages with
built-in translation tables and automatic identification of the "ASCII" trans-
fer character set via Attribute packets. This facility supports files stored
using numerous IBM Country Extended Code Pages and permits transfers using
character sets ASCII, ARABIC, CYRILLIC, GREEK, HEBREW, JAPAN-EUC, KATAKANA,
LATIN1, LATIN2, LATIN3, and THAI. See Table 1-1 for a display of the allowed
combinations of character sets. See also file ISOK7.TXT in the Kermit dis-
tribution for a somewhat outdated description of the protocol extensions.
Kermit-370 currently supports text files in the following languages:
Afrikaans, Albanian, Arabic, Bulgarian, Byelorussian, Catalan, Czech, Croatian,
Danish, Dutch, English, Esperanto, Faeroese, Finnish, French, Gaelic, Galician,
German, Greek, Hebrew, Hungarian, Icelandic, Italian, Japanese (Katakana and
Kanji), Lao, Latin, Macedonian, Maltese, Norwegian, Polish, Portuguese, Que-
chua, Romanian, Russian, Serbian, Slovak, Slovene, Spanish, Swahili, Swedish,
Thai, Turkish, Ukrainian, and Volapuk. Visual representations of the charac-
ters sets may be found in the ISO register (for transfer) and in various IBM
documents, such as S544-3156 "About Type" (for files).
Kermit itself normally operates in English, but there are versions with the in-
teractive messages translated into other languages. The currently available
languages are Czech, Dutch, Finnish, French, German, Italian, Polish, Por-
tuguese, Russian, and Spanish. Special thanks to Petr Adelsberger, Mauricio
Alvarenga, Lorenzo Beltrame, Janusz Bien, Jose Eduardo de Lucca, Richard
Gatersleben, Kauko Haumalainen, Jaroslaw Kurowski, Roberto Magana, Alberto Rio,
Christian Robert, Gisbert Selke, Karel Smuk, Rob van der Wal, Konstantin
Vinogradov, and Joachim Wlodarz for preparing these translations. See the in-
stallation guide for details on the alternate-language versions. There are no
translations yet of the help files, nor of this document.
-------------------------------------------------------------------------------
Transfer character set
Local ASCII ARAB. CYR. GREEK HEB. JAPAN KATAK. L1 L2 L3 THAI
CP037 * **
CP273 **
CP275 **
CP277 **
CP278 **
CP280 **
CP281 * **
CP282 **
CP284 **
CP285 **
CP290 * **
CP297 **
CP420 **
CP424 **
CP500 * * **
CP838 **
CP870 **
CP871 **
CP875 **
CP880 * **
CP905 **
CZECH *
DKOI * ***
EBCDIC * * ***
H-EBCD * *
KANJI *
Table 1-1: Allowed character set combinations in Kermit-370
All allowed combinations are marked with asterisks, and the preferred
combination in each row or column is the one with the most asterisks. Whenever
a character set is specified, either directly or through an Attribute packet,
the other category of character set is checked to see if it makes up an allowed
combination. If not, it is forced to the preferred character set.
-------------------------------------------------------------------------------
As nearly as possible, the tables in Kermit-370 are invertible, but all of the
character sets reserve many (typically 65) code points for control characters
and leave them officially undefined and unprintable. This applies both to IBM
code pages and ISO standard 8-bit character sets. Although 33 of the controls
have widely accepted mappings, the others do not, and Kermit-370 currently uses
those given in an appendix of IBM's VS/Fortran Reference Manual. Needless to
say, such translations are arbitrary and may be invalidated by future decisions
at IBM or ISO. Still, most of the translations are likely to be stable in the
long run. Table 1-2 shows the current translation from LATIN1 to EBCDIC, which
is likely to be the most often used. Other translations, including the reverse
ones, may be displayed using the TDUMP subcommand of Kermit-370.
-------------------------------------------------------------------------------
-0 -1 -2 -3 -4 -5 -6 -7 -8 -9 -A -B -C -D -E -F
0- 00 01 02 03 37 2D 2E 2F 16 05 25 0B 0C 0D 0E 0F
1- 10 11 12 13 3C 3D 32 26 18 19 3F 27 1C 1D 1E 1F
2- 40 5A 7F 7B 5B 6C 50 7D 4D 5D 5C 4E 6B 60 4B 61
3- F0 F1 F2 F3 F4 F5 F6 F7 F8 F9 7A 5E 4C 7E 6E 6F
4- 7C C1 C2 C3 C4 C5 C6 C7 C8 C9 D1 D2 D3 D4 D5 D6
5- D7 D8 D9 E2 E3 E4 E5 E6 E7 E8 E9 AD E0 BD 5F 6D
6- 79 81 82 83 84 85 86 87 88 89 91 92 93 94 95 96
7- 97 98 99 A2 A3 A4 A5 A6 A7 A8 A9 C0 4F D0 A1 07
8- 20 21 22 23 24 15 06 17 28 29 2A 2B 2C 09 0A 1B
9- 30 31 1A 33 34 35 36 08 38 39 3A 3B 04 14 3E FF
A- 41 AA 4A B1 9F B2 6A B5 BB B4 9A 8A B0 CA AF BC
B- 90 8F EA FA BE A0 B6 B3 9D DA 9B 8B B7 B8 B9 AB
C- 64 65 62 66 63 67 9E 68 74 71 72 73 78 75 76 77
D- AC 69 ED EE EB EF EC BF 80 FD FE FB FC BA AE 59
E- 44 45 42 46 43 47 9C 48 54 51 52 53 58 55 56 57
F- 8C 49 CD CE CB CF CC E1 70 DD DE DB DC 8D 8E DF
Table 1-2: EBCDIC (hexadecimal) code points for LATIN1
This table shows the values of the EBCDIC equivalents for the code points in
the LATIN1 character set. The values are arranged in LATIN1 collating
sequence, and the rows and columns are labeled with the first and second
digits, respectively, of the LATIN1 code points. For example, LATIN1 code 41
(hex) is upper-case "A", and the intersection of row "4-" and column "-1" has
the value C1 (hex), which is the EBCDIC code for "A". Rows "0-", "1-", "8-",
and "9-" are officially undefined in ISO 8859-1 and so, in principle, could be
changed at some future time, especially "8-" and "9-". Note that this table
uses a format close to that of the TDUMP subcommand and of the Kermit code
itself, but character-set tables are often displayed with the rows and columns
interchanged.
-------------------------------------------------------------------------------
Besides converting files for transmission, Kermit-370 must also compensate for
the EBCDIC/ASCII translation performed by some front ends and must, therefore,
be able to apply the exact reverse translations on both input and output. This
is the "middle layer" of translation described earlier for "TTY" devices. Con-
sider the fate of a Left Square Bracket character in an inbound packet on a
"TTY" line. It begins as ASCII code x'5B' (91 decimal), but the front end
translates it to EBCDIC before presenting it to Kermit-370. In this example,
suppose it becomes EBCDIC code x'4A' (74 decimal) instead of the standard x'AD'
(173 decimal). Then, Kermit must be primed with a SET TETOA 74 91 so that,
when reconstructing the original ASCII packet, the character becomes x'5B'
again. Otherwise, the packet checksum will appear invalid. Kermit comes with
a pair of default tables, but it may be necessary to customize them, as this
example shows. The following procedure will reveal any changes needed. The
procedure has two stages: the first is for any line-mode front end, and the
second only for front ends capable of full 8-bit data transfer. Note that, al-
though the discussion refers to hexadecimal values, the Kermit-370 SET subcom-
mands require decimal numeric arguments. Also, note that this procedure as-
sumes you will run Kermit with TTABLE set on; hence, the references to
Kermit-370 tables are to TATOE and TETOA. If you choose to define Kermit's
file translation to match that of the front end, you should leave TTABLE set
off and remove the T's from the SET subcommands described below. This will
also turn off the automatic switching of translation tables according to the
Attribute packets received from the other Kermit. Under CMS, you must issue a
CMS SET INPUT and a CMS SET OUTPUT before starting this procedure.
1. Create a file containing all the non-control EBCDIC characters (hex
codes 40-FF) and display the file on any available ASCII terminal
hooked up to the line-mode front end in question.
2. If any printable ASCII character is missing from the display, Kermit
cannot work through this front end (unless you modify the tables in
the front end itself).
3. If any ASCII character appears twice, there is no cause for alarm.
4. If any ASCII character does not appear where it should, according to
Table 1-3, a SET TATOE must be added to the system INIT file. For
example, if EBCDIC code 5F (Not Sign, according to the Appendix) ap-
pears as an ASCII Tilde (7E), but EBCDIC A1 (Tilde) does not, a SET
TATOE 126 95 is required. Warning: characters considered unprint-
able by the front end are likely to be filtered out entirely when
you display the file; do not expect the display to line up just like
Table 1-3.
5. Create a file on the mainframe using an ASCII terminal for input,
and enter all 95 printable ASCII characters in collating sequence.
You can presumably save time by skipping the 52 upper- and
lower-case letters and the 10 digits.
6. Display the file from the previous step in hexadecimal or other bi-
nary form.
7. If any duplicates appear among the 95 characters (or 33, if you have
taken the short cut), Kermit cannot work through this front end (un-
less you modify the tables in the front end).
8. Compare the hexadecimal codes with rows 2-7 of Table 1-2. If a dis-
crepancy appears, a SET TETOA must be added to the system INIT file.
For example, if ASCII Left Bracket (5B) appears as EBCDIC 4A, a SET
TETOA 74 91 is needed. At this point, the first stage is complete.
9. If 8-bit line-mode file transfer is desired, you must now verify the
extended character set. Display the file of EBCDIC codes again,
this time using a terminal with extended character set display, or
capture the session with a micro Kermit and display the resulting
file in hexadecimal. If any code in the range A0-FE does not ap-
pear, the front end will not allow 8-bit Kermit data transfers.
Generate SET TATOE entries for the entire range, as needed, just as
in the example given for 7-bit codes. If the front end's trans-
lation tables are documented, it may be easier to work from the
manual, but you must be sure that you have tables for all of the
translations that occur on the data path.
10. Create a file of the 95 extended ASCII codes A0-FE, if possible, by
using a terminal capable of transmitting those codes or transmitting
a pre-made file "raw". If necessary, use the appropriate table(s)
in the manual(s) instead.
11. Again, if any duplicates appear, this front end is incapable of
8-bit file transfers. Otherwise, generate SET TETOA entries as be-
fore.
-------------------------------------------------------------------------------
0 1 2 3 4 5 6 7 8 9 A B C D E F
4- . < ( + |
5- & ! $ * ) ; ^
6- - / , % _ > ?
7- ` : # @ ' = "
8- a b c d e f g h i
9- j k l m n o p q r
A- ~ s t u v w x y z [
B- ]
C- { A B C D E F G H I
D- } J K L M N O P Q R
E- \ S T U V W X Y Z
F- 0 1 2 3 4 5 6 7 8 9
Table 1-3: Character graphics for EBCDIC codes
This table shows the representations of the EBCDIC codes arranged in EBCDIC
collating sequence, row by row. Codes that do not correspond to ISO 646
characters (7-bit ASCII), have been left blank. One special case is the EBCDIC
code 5F, which represents a Not Sign in IBM's CP037, but which is traditionally
mapped to the ASCII Circumflex, as shown here. WARNING: this manual may have
been printed on a device that maps characters differently. Consult the
Appendix to verify.
-------------------------------------------------------------------------------
1.2. File Attributes
Kermit-370 attempts to send and receive file attributes along with the files
themselves. Before Kermit receives a file, it compares the Length attribute
(if available) with the amount of disk space available (if known) so that the
file can be rejected if it will not fit. In addition, the Type, Access, Encod-
ing, Disposition, and Format attributes, if any, are interpreted in order to
match the received file to the original as nearly as possible. All other at-
tributes (including Date) are simply ignored. For Type, Kermit recognizes text
and binary specifications; for Access, it recognizes append, normal, and super-
sede; for Encoding, it recognizes ASCII, extended, and EBCDIC (which it treats
as binary); for Disposition, it recognizes mail, print, and job; and for For-
mat, it recognizes text, D-binary, V-binary, binary, and LRECL. Any other
values are rejected.
On sending a file, if the other Kermit is willing to accept Attribute packets,
Kermit-370 sends the Type, Encoding, Format, Date, and Length attributes (un-
less some or all of them have been disabled -- see the SET ATTRIBUTE subcom-
mand).
Unfortunately, the set of file attributes defined in the Kermit protocol is not
well matched to the needs of IBM 370 file systems, so that much of the
machinery for creating and interpreting of Attribute packets is useless. For
example, the "Format" attribute, which should logically specify the record for-
mat of the received file, gives only the format of the file in transmission and
cannot distinguish between fixed-length and varying-length records for text
files. This limitation is partly due to the fact that other Kermits do not
generally support the same attributes. In short, even if the protocol made it
possible, some of the important attributes would never be specified anyway.
Nonetheless, efforts are being made to extend the protocol to be more com-
prehensive.
1.3. Program Operation
Kermit-370 can be invoked directly or from a command procedure. In either
case, it reads and executes subcommands sequentially until directed to quit,
and then returns. A subcommand consists of one or more fields (words)
separated by spaces or commas.
Upon startup, the program looks for two (optional) initialization files, one
system-wide and a second specific to the user. Both filespecs are, of course,
system-dependent. The purpose of these files is to allow Kermit to be cus-
tomized for a particular system and for a user's specific settings without
changing the source code. The system-wide file, which is maintained by a sys-
tems programmer, should contain Kermit subcommands that all users would need to
issue in order for Kermit to run on the system, such as subcommands to modify
the ASCII/EBCDIC tables used by Kermit-370. The user-specific file, if any,
should contain subcommands that the user generally issues every time Kermit is
run. Kermit-370 executes any subcommands found in these files as though they
were typed at the terminal. Here is a sample INIT file:
* Asterisk in column one is a comment.
set transfer character-set latin1
set file collision rename
set block 3
During interactive execution, you may use the built-in help feature while
typing Kermit-370 subcommands. A question mark ("?") typed at almost any point
in a subcommand, followed by a carriage return, produces a brief description of
what is expected or possible at that point. Moreover, mistyping a subcommand
will generally produce a helpful error message or a list of possible options at
the point of error. Keywords in such lists are displayed with the
minimum-length abbreviation in upper case and the remainder, if any, in lower
case. In entering Kermit subcommands, any keyword may be shortened to any sub-
string that contains the minimum abbreviation.
Besides knowing the mechanics of entering Kermit subcommands and interpreting
responses, the user must understand which subcommands are necessary. The
default values for Kermit-370 options have, in some cases, been constrained by
a desire for continuity, so that some of the default behavior is distinctly
"suboptimal." An example of this is the traditional 80-byte default RECEIVE
packet size, which generally gives much slower transmission than a size of 1000
or more. Such options are flagged in this chapter with a notation that they
perhaps ought to be set in the INIT files. Note, however, that the interplay
of Kermit protocol sometimes provides a performance upgrade with no special ac-
tion required from the Kermit-370 user. An example of this is the SEND
packet-size, which is always under the control of the other Kermit. Kermit-370
always sends packets as long as the other Kermit allows, unless the frequency
of transmission errors indicates that shorter packets would be more efficient
(see the subcommand SET SPEED).
Kermit-370 also attempts to produce optimal results by adapting to the file at-
tributes sent by the other Kermit along with the files, such as TYPE and LRECL.
Such attributes, when sent by the other Kermit, temporarily override the cur-
rent settings in Kermit-370 during the reception of the associated file.
Potentially even more importantly, Kermit-370 automatically recognizes the
character set used for the file transfer and chooses, if necessary, a com-
patible character set for file storage. Table 1-1 shows the currently sup-
ported list of character sets. As with any automatic operation, Kermit's
honoring of the transmitted attributes may need to be suppressed in part or al-
together, and the SET ATTRIBUTE subcommand provides this capability.
Another attribute that Kermit-370 supports is file disposition, which allows
files to be received and immediately retransmitted as electronic mail, sent to
a printer, or submitted as a batch job. These three options are highly
site-specific and are implemented as a set of three host commands with similar
calling sequences. In each case, the command is invoked in two different ways
in the process of processing the file. It is called without any filespec or
other options as soon as the corresponding attribute is recognized by
Kermit-370. If the command is not implemented or for some reason returns a
non-zero completion code (such a code should be negative, if at all possible),
Kermit-370 rejects the file using the normal attribute exchange mechanism.
Otherwise, the file is received as usual, and the command is invoked again at
the end-of-file. The second time, the command is given the name of the
received file and the options received from the sending Kermit (such as the
list of recipients for electronic mail). The command is then responsible for
disposing of the file (and deleting it, if desired). If, for any reason, the
file cannot be sent as required, the command should return a negative comple-
tion code (or non-zero, at any rate), and Kermit-370 will send back an error
message to the sending Kermit. The command itself should refrain from issuing
any messages of its own or permitting commands that it invokes to issue mes-
sages. See the beginning of the chapter on the system-specific variant of
Kermit-370 for the exact command syntax. Some sample implementations of such
commands may be available in the Kermit distribution -- refer to the
system-specific installation guide for a list of samples.
1.4. Kermit-370 Subcommands
The following is a summary of Kermit subcommands. The starred subcommands can
be issued as remote Kermit commands to Kermit-370 when it is in server mode.
System-specific subcommands are omitted from this list.
BYE logs out other Kermit server.
CWD* establishes a new working directory.
DIRECTORY displays all or part of the disk directory.
ECHO a line back to the user.
EXIT from Kermit-370.
FINISH other Kermit server.
GET file(s) from a Kermit server.
GIVE* creates a TAKE file snapshot of a table.
HELP about Kermit-370.
HOST* executes a system command.
KERMIT* executes a Kermit subcommand.
QUIT from Kermit-370.
RECEIVE file(s) from other Kermit.
SEND file(s) to other Kermit.
SERVER mode of remote operation.
SET* various parameters.
SHOW* various parameters.
SPACE* displays disk storage allocation.
STATUS* inquiry.
STOP easy escape from protocol mode.
TAKE* subcommands from file.
TDUMP* dumps the contents of a table.
TYPE* a file.
VERSION* of Kermit-370.
XECHO echoes a line (transparently).
XTYPE displays a file (transparently).
Although Kermit-370 is generally a remote Kermit, it has the capability of com-
municating with another Kermit in server mode. In that situation, the
subcommand prefixes REMOTE and LOCAL refer to the Kermit server and Kermit-370,
respectively, even when Kermit-370 is, strictly speaking, the remote Kermit.
To help avoid confusion, this chapter will often use the term "foreign" to
apply to the Kermit at the other end from Kermit-370. All the above subcom-
mands may be preceded by the LOCAL prefix, but only certain ones are valid with
REMOTE, including some not shown here. See the description of the SERVER sub-
command for details. Any text replies Kermit-370 gets from the foreign Kermit
server are added to a disk file (whose filespec is, of course,
system-dependent). Such a transaction can be carried out, for example, under
control of a TAKE file if Kermit-370 is not operating locally. If the local
Kermit has a "magic" character sequence that switches it from terminal emula-
tion to server mode, then an entire session could be controlled from the
mainframe, possibly in response to a single command issued by a naive user.
For example,
.grab
Kermit-370 is invoked and executes the following TAKE file
ECHO Serve Me! the local Kermit switches to server mode
GET file.a the server uploads file.a
FINISH the server switches back to terminal mode
The remainder of this section describes subcommands with special meaning or use
in Kermit-370, except the highly system-dependent ones. For the latter, refer
to the appropriate chapter. Subcommands are listed in alphabetical order.
THE ECHO AND XECHO SUBCOMMANDS
Syntax: [X]ECHO line
These subcommands type the line back at the user. The line may contain control
characters or any desired text, including upper or lower case. These subcom-
mands may be used, for example, to test the ASCII/EBCDIC translate tables or to
issue coded commands to the user's terminal. XECHO differs from ECHO primarily
in that it sends the text as a raw transmission according to the current CON-
TROLLER setting. Thus, XECHO will, if necessary, break the text into pieces no
larger than the current SEND PACKET-SIZE and will use transparent mode if CON-
TROLLER is SERIES1, GRAPHICS or AEA. It also offers its own brand of
control-character quoting, using the "^" character to indicate that only the
five low-order bits of the ASCII codes are to be used. Thus, "^a", "^A", and
"^!" are all translated to SOH (CTRL-A), while "^[" becomes ESC. However,
there must be one exception for "^" itself: "^>" and "^~" are both translated
to RS (CTRL-^), but "^^" becomes just "^". XECHO also decodes 8th-bit quoting,
just as in Kermit protocol, and this feature can be disabled by setting 8th-bit
quoting off. For example, if the 8th-bit quote character is "&", entering the
subcommand "XECHO &A" will transmit a code x'C1', but the same subcommand with
quoting off will transmit two bytes: x'2641'.
THE GET SUBCOMMAND
Syntax: GET [foreign-filespec [filespec]]
The GET subcommand tells Kermit to request a file or file group from the other
system, which must have a Kermit running in server mode. Provided the other
Kermit complies, the effect is the same as if SEND foreign-filespec had been
issued directly to the other Kermit and RECEIVE [filespec] to Kermit-370. If
this subcommand is issued without any arguments, Kermit-370 will prompt the
user for both foreign and native filespecs (and will insist on getting the
former, but will do without the latter). See the respective SEND and RECEIVE
subcommands for a description of the each filespec.
THE GIVE SUBCOMMAND
Syntax: GIVE table-name filespec
This compares the named translation or selection table with its current default
values and saves the differences in the form of a TAKE file consisting of SET
subcommands that would convert the default into the current arrangement. ATOE,
ETOA, TATOE, and TETOA are the available translation tables, and CONTROL-CHAR
is the selection table. The details of the filespec are system-dependent, but
those details will, in general, be the same as for the TAKE subcommand (q.v.).
In the case of tables ATOE and ETOA, the current defaults are the values from
the most recent character-set definition, if any, but the defaults for TATOE
and TETOA always remain at the initial values. See the SET FILE CHARACTER-SET
and SET TRANSFER CHARACTER-SET subcommands for more details.
THE HINTS SUBCOMMAND
Syntax: HINTS
This subcommand produces a screenful of suggestions for Kermit operation, in-
cluding warnings about any current settings that may be undesirable.
THE HOST SUBCOMMAND
Syntax: HOST text of command
This issues a command to the host operating system from Kermit-370. When a
command returns a non-zero completion code, the code will be displayed.
Generally, the name of the system (e.g., CMS) is treated as a synonym for the
HOST subcommand.
When Kermit-370 is in (non-local) server mode, you must avoid sending it any
HOST commands that trigger full-screen terminal I/O, since the server-client
interface does not provide any full-screen terminal emulation, nor is
Kermit-370 usually able to intercept such I/O in any case.
THE KERMIT SUBCOMMAND
Syntax: KERMIT text of subcommand
This is provided for redundancy as the counterpart of the HOST subcommand.
Kermit-370 executes the specified text as a Kermit subcommand just as if the
LOCAL prefix had been entered. Note, however, that the specified text must not
begin with a second KERMIT prefix.
THE RECEIVE SUBCOMMAND
Syntax: RECEIVE [filespec]
The RECEIVE subcommand tells Kermit-370 to accept a file or file group. The
user must issue the corresponding SEND subcommand to the other Kermit. When
files are received, their names are recorded in a transaction log in memory and
may be viewed later via the TDUMP NAMES subcommand. The log contains the names
along with the file sizes and any relevant error messages. Another form of log
may be provided through an accounting exit routine, which is called at the end
of every RECEIVE session. Such an accounting log may contain elapsed time and
numbers of bytes sent, received, and transferred to/from disk. If an error oc-
curs during the file transfer, as much of the file as was received is saved on
disk. If, however, the sending of a file is cancelled by the user of the
foreign system, Kermit-370 will discard whatever had arrived, unless FILE COL-
LISION is APPEND or INCOMPLETE is KEEP.
Kermit-370 has a context-dependent maximum record length, and received records
longer than that will be folded or truncated to the proper length; when this
happens, Kermit may or may not stop, depending on the FILE subparameter
LONGLINE. If truncation does occur, Kermit will later note the fact as an er-
ror (unless something more serious happens in the meantime). In addition, when
a fixed record length is specified, received records are padded to the correct
length. The padding character is a blank for text files and a null for binary
files. Received binary (but not V-binary or D-binary) files are treated as
byte streams and broken up into records all of the logical record length, i.e.,
folded. For more details on the RECEIVE subcommand syntax and operation, see
the chapter on the desired system-specific variant of Kermit-370 under both
RECEIVE and SET FILE. See also (in this chapter) the SET FILE LONGLINE subcom-
mand for details on record truncation and folding.
THE SEND SUBCOMMAND
Syntax: SEND [filespec[<options>] [foreign-filespec]][, ...]
The SEND subcommand tells Kermit-370 to send a file or file group to the other
(foreign) Kermit. If no such file exists, Kermit-370 simply displays an error
message and issues another prompt. Like RECEIVE, SEND keeps a transaction log
of all files transferred in a group and calls the accounting exit routine at
the end of the session. If this subcommand is issued without any arguments,
Kermit-370 will prompt the user for both native and foreign filespecs (and will
insist on getting the former, but will do without the latter). Either with or
without prompting, SEND allows specifying a list of up to 13 files (or file
groups) separated by commas. (By ending the command line or subsequent
response with a comma, the user ensures further prompting.) In this syntax,
the options enclosed in angle brackets may be regarded as part of the native
filespec. There must be no intervening blanks. At present, the only supported
option is a range of line numbers within the file to be sent. The range takes
the form [n][-[m]], where n is the number of the first line to send (counting
from 1), and m is the last. Omitting either number implies the corresponding
limit is the physical beginning or end of the file. This same option syntax
may be used in some commands issued to the foreign Kermit, namely, those in-
volving filespecs in 370 form. In particular, GET and REMOTE TYPE can use this
syntax. Note that a trailing ">" is used by some other Kermits, such as
MS-Kermit, to indicate redirection of the output from REMOTE commands to disk.
In order to transmit the ">" and also prevent the redirection to disk, it would
be necessary to add an explicit redirection to the terminal, as in
REM TYPE filespec<n-m> > CON
Although file transfers cannot be cancelled from the 370 side, Kermit-370 is
capable of responding to "cancel file" or "cancel batch" signals from the local
Kermit; these are typically entered by typing CTRL-X or CTRL-Z, respectively.
When Kermit-370 sends files using long packets (longer than 94), the throughput
is especially sensitive to the level of noise on the line because retries are
so time-consuming. Therefore, Kermit-370 imposes an extra, heuristic size
limit on packets when retries have been found necessary. When that is the
case, after every 15 packets, Kermit computes the packet size for maximum
throughput assuming that the transmission errors were due to sparse,
Poisson-distributed noise bursts. The result of this calculation is then used
as another limit on the size of outgoing packets besides the one specified by
the other Kermit. If no retries are required, then Kermit-370 assumes the line
to be noiseless and sends packets of the maximum length the other Kermit al-
lows. The algorithm is explained in Kermit News V. 3 #1. For more details on
the SEND subcommand syntax and operation, see the chapter on the desired
system-specific variant of Kermit-370.
THE SERVER SUBCOMMAND
Kermit-370 is capable of acting as a server. In server mode, Kermit-370 can
send and receive files, execute host commands, execute a restricted set of Ker-
mit subcommands, and perform a variety of generic Kermit functions. The fol-
lowing list shows the typical local Kermit commands along with the server func-
tions they elicit. When Kermit-370 is talking to another Kermit running in
server mode, these same subcommands may be used in the other direction.
BYE log out the Kermit server.
FINISH server mode.
GET a file or files from the server.
REMOTE
COPY a file or files.
CWD set new working directory.
DELETE a file or files.
DIRECTORY display file attributes.
HELP display a command summary, such as this.
HOST execute a system command.
KERMIT execute a Kermit-370 subcommand.
PRINT send a file to be printed by the server.
RENAME a file or files.
SPACE display disk space.
TYPE a file.
SEND a file or files to the server.
If your local Kermit does not support the REMOTE KERMIT command, you may need
to issue SET subcommands to select various options before typing the SERVER
subcommand. Once in server mode, Kermit-370 will await all further instruc-
tions from the client Kermit on the other end of the connection until a FINISH
or BYE command is given.
Command execution in server mode is different in some respects from normal
operation. First of all, some Kermit subcommands are not allowed (see the list
at the beginning of this section). Moreover, command errors always terminate
any active TAKE file. Also, all commands will be run in the special environ-
ment that Kermit sets up during protocol transfers. Among other things, Kermit
intercepts all terminal I/O (if possible) in this environment in order to
transmit the data to the local Kermit as text packets.
Note that some operations can be requested by several different commands. If
for example, the IBM 370 system has a command "PRT" for displaying a file, a
user interacting with a Kermit-370 server can choose to display a file by is-
suing any of the commands: REMOTE TYPE, REMOTE HOST PRT, REMOTE KERMIT TYPE,
REMOTE KERMIT HOST PRT, or (if SYSCMD has been set ON) REMOTE KERMIT PRT. The
first form simply transfers the requested file as text, but the others invoke
the "PRT" command with any specified options, intercept the terminal output,
and return the results to the local Kermit. The first form is also distin-
guished by the fact that the line range may be specified in the same manner as
in the SEND subcommand. The syntax of the others is system-dependent.
THE SET SUBCOMMAND
Syntax: SET parameter [value]
The SET subcommand establishes or modifies various parameters controlling file
transfers. The values can, in turn, be examined with the SHOW subcommand.
Some parameters have two levels. In particular, there are two matching lists
of SEND and RECEIVE sub-parameters corresponding to the values exchanged by
Kermits in the Send-Init/ACK sequence. For each of these SEND/RECEIVE pairs
one element is encoded in outgoing parameter packets, and the other is decoded
from incoming ones. Setting the latter by hand may be needed to establish con-
tact and also has the effect of redefining the default value for decoding from
subsequent parameter packets. Generally, the distinction between SEND and
RECEIVE parameters is unambiguous, the only exception being TIMEOUT (q.v.).
The following SET subcommands are available in Kermit-370:
ATOE Modify the Kermit-370 ASCII-to-EBCDIC table.
ATTRIBUTE Determine A-packet generation.
BLOCK-CHECK Level of error checking for file transfer.
CONTROLLER Indicate type of terminal connection.
CONTROL-CHAR Set prefixing state.
DEBUG Log packet traffic during file transfer.
DELAY Length of pause before a SEND subcommand.
EOF Text file truncation at CTRL-Z.
ETOA Modify the Kermit-370 EBCDIC-to-ASCII table.
FILE Attributes for incoming or outgoing files...
CHARACTER-SET ... for 370 storage.
COLLISION ... treatment for duplicate names.
LONGLINE ... treatment of too-long records.
OVERWRITE ... treatment of attributes.
TYPE ... text or binary.
other ... system-specific attributes.
FOREIGN Strings added to outgoing filespec...
PREFIX
SUFFIX
INCOMPLETE Determine the action on an aborted file transfer.
LINE Specify alternate communication line.
MARGIN for sending files...
LEFT
RIGHT
PROMPT For Kermit-370 subcommands.
RETRY Maximum retry count...
INIT ... for initial packet exchange.
PACKET ... per packet for ongoing transfer.
SERVER-TIMEOUT Spacing between server NAK's.
SPEED Line speed for packet-size calculations.
SYSCMD Try apparently invalid Kermit subcommands on host system.
TABS-EXPAND Determine tab-to-space conversion on reception.
TAKE
ECHO Echo subcommands read from TAKE files.
ERROR-ACTION Exit from TAKE file on command error.
TEST Facilitate testing of Kermit.
TATOE Modify the Kermit-370 ASCII-to-EBCDIC table.
TETOA Modify the Kermit-370 EBCDIC-to-ASCII table.
TRANSFER Options for transmission...
CHARACTER-SET ... of text files.
LOCKING-SHIFT ... protocol extension.
TTABLE Determine which tables undo the terminal translation.
8-BIT-QUOTE Determine state of 8th-bit prefixing.
SEND or RECEIVE
END-OF-LINE Packet terminator.
PACKET-SIZE Maximum packet size.
PAD-CHAR Character to insert before each packet.
PADDING Number of pad characters to insert.
PARITY Indicate if 7-bit or 8-bit data.
QUOTE Use to quote control characters in packets.
START-OF-PACKET Packet beginning marker.
TIMEOUT Time limit for response.
SET ATOE etc.
Syntax: SET table [num1 num2]
This modifies one of the ASCII/EBCDIC translation tables used by Kermit-370
(for example, to conform to your system). The valid table names are ATOE,
ETOA, TATOE, and TETOA. The arguments are, respectively, the offset within the
named table and the new value for that offset. If the arguments are omitted,
the table is restored to its initial arrangement. Both num1 and num2 should be
in the range 0-255 (decimal). For example, in ATOE or TATOE, the offset is the
ASCII character code, and the new value is the new EBCDIC result code. In-
itially, ATOE and TATOE each contain two identical copies of the 7-bit ASCII
character table. Helpful hint: if you have files that make use of extended
(8-bit) ASCII codes and wish to upload them via Kermit-370, be sure to define
unique EBCDIC equivalents of all the needed 8-bit ASCII codes or else treat
such files as binary data. Any time you use the SET ATOE or SET ETOA subcom-
mands, that has a side effect equivalent to SET ATTRIBUTE ENCODING OFF (q.v.).
If the extended ASCII character set is one of those supported for file transfer
in Kermit-370, you need only issue a SET TRANSFER CHARACTER-SET (q.v.).
Note: the meaning of the tables depends on the TTABLE setting -- if TTABLE is
OFF, the TATOE and TETOA tables are not used.
SET ATTRIBUTE
Syntax: SET ATTRIBUTE [attribute] ON or OFF
The individual attributes are LENGTH, TYPE, DATE, CREATOR, ACCOUNT, AREA,
PASSWORD, BLOCKSIZE, ACCESS, ENCODING, DISPOSITION, PROTECT, ORIGIN, FORMAT,
SYS-INFO, and BYTE-LENGTH. Kermit-370 distinguishes between the two forms of
this subcommand by counting "words". In order to see the list of supported at-
tributes, you must enter "SET ATTR ? ?"; if you enter just "SET ATTR ?", Kermit
will list just the alternatives ON and OFF.
ON The specified attribute is to be processed, or attribute packets are
generated for all outgoing files, provided the other Kermit indicates
the ability to accept them. (Default).
OFF The specified attribute is to be ignored and not generated, or at-
tribute packets are never generated.
SET BLOCK-CHECK
Syntax: SET BLOCK-CHECK type
This determines the type of block check used during file transfer, provided the
other Kermit agrees. Valid options for type are: 1-byte (for a one-character
checksum), 2-byte (for a two-character checksum), 3-byte (for a three-character
CRC), and Blank-free-2 (for a shifted two-character checksum that avoids using
blanks. This is one of only two Send-Init parameters that cannot be SET
separately for SEND and RECEIVE.
SET CONTROLLER
Syntax: SET CONTROLLER type
The type may be TTY, SERIES1, GRAPHICS, AEA, FULLSCREEN, VTAMTTY, or NONE.
Kermit-370 automatically determines whether you are connected via a Series/1
(or similar) emulation controller or a TTY line. In some circumstances, such
as when the connection is through a non-graphics-capable 3174 port, Kermit will
set CONTROLLER to NONE, which has the effect of disabling file transfers. This
subcommand is provided, though, to allow the automatic choice to be superseded,
and because Kermit may not be able to distinguish between Series/1-type and
other 3270-emulation controllers. In particular, there is no way to distin-
guish between FULLSCREEN and GRAPHICS from within Kermit. When CONTROLLER is
set to SERIES1, GRAPHICS, or AEA, Kermit disables the 3270 protocol conversion
function by putting the terminal controller into "transparent mode", which al-
lows Kermit packets to pass through intact. Note: an incorrect CONTROLLER set-
ting may lock up or wipe out your session when you try to transfer files.
Kermit operation is possible through an IBM 3708 front end, but only in a
rather specific configuration. See the installation guide for your variant of
Kermit-370 for the details of that and other hardware-related restrictions and
configurations.
SET CONTROL-CHAR
Syntax: SET CONTROL-CHAR mode [number]
The mode may be PREFIXED (normal Kermit protocol for control characters) or UN-
PREFIXED. In the latter case, the specified control character (given as a
decimal number in the range 0-31 or 128-159) is transmitted "as is". If the
number is omitted, then all control characters are set accordingly. Kermit-370
automatically overrides the user's settings for certain characters used for
Kermit protocol: the start-of-packet, the end-of-packet, the handshake (if
set), and XOFF (not really used, but too dangerous to send). Sending control
characters without prefixes can speed up transfers of binary files.
The status of prefixing is initially "PREFIXED" for all control characters. It
can be displayed by the TDUMP CONTROL subcommand, or saved in the form of a
TAKE file by the GIVE CONTROL subcommand (q.v.).
SET DEBUG
Syntax: SET DEBUG OFF or ON [RAW] [I/O] [SAVE] [LONG] [TIME]
Note: any combination, in any order, of RAW, I/O, SAVE, and TIME may follow or
replace ON. Each of the three implies ON.
ON Keep a journal of all packets sent and received in a log file on disk.
If the file already exists, it is erased and overwritten. The filespec
of the log is, of course, system-dependent. All packets are logged in
EBCDIC for legibility, even when CONTROLLER is set to SERIES1,
GRAPHICS, or AEA.
RAW The same as ON, but packets are logged in the form that is passed to or
from the operating system, i.e., EBCDIC for TTY or VTAMTTY terminals,
and ASCII for SERIES1, GRAPHICS, and AEA terminals. This option is
generally not recommended; I/O is preferable.
I/O The same as ON, but the log includes additional transmission status in-
formation, such as the AID returned by a full-screen device. See below
for a summary of the log formats.
SAVE The same as ON, but the log file is closed after each entry is added,
so that, if the session is abnormally terminated, the log file will be
complete and readable.
LONG The same as I/O, but the additional information is not truncated to 36
bytes.
TIME Used only with I/O or LONG. The lines of hexadecimal dump are tagged
with the time of day from the CPU clock, truncated to the nearest
second.
OFF Stop logging packets and close the the log file. (Default.)
Often, problems with Kermit file transfers or server-mode operations can be
diagnosed by setting DEBUG on in one or both Kermits, regardless of where the
problems actually lie. For Kermit-370, the maximum amount of information can
generally be obtained by setting DEBUG to I/O or LONG, but the format of the
log depends somewhat on which variant of Kermit-370 is involved. Before ex-
amining the log, you should set DEBUG OFF either explicitly or by exiting from
Kermit-370.
There is an optional feature for logging dumps of storage blocks at selected
points in the execution. By default, this feature is disabled (at assembly
time) by having the variable symbol &KTRACE set to NO and also by virtue of the
fact that no calls to the dump routine are present in the distribution code.
Further, the dumps are suppressed unless both DEBUG and TEST (q.v.) are set on.
To select when and what blocks to dump, it is necessary to insert calls to
KHDMP at appropriate points in the source before assembling. Each such call
generates a dump each time it is executed, provided that DEBUG and TEST are
set, and the contents of all registers are preserved. The call specifies the
starting address, the length, and a short title for the block. Only eight
characters of the title will be used. Some examples:
KHDMP ATOE+128,128,'ATOEhigh'
Dump the 2nd half of the ATOE table.
KHDMP KHDSAV,20,'R14 - R2'
Dump registers 14-2.
KHDMP 32(,13),40,'**R3-R12'
Dump registers 3-12.
KHDMP (3),(0),'**QBLOCK'
Dump block addressed by R3 with length specified in
R0.
There is another debugging facility that is enabled by the variable symbol
&KTRACE along with the dump option, namely, an execution trace. There is a
circular buffer of trace elements in Kermit's working storage, and a new ele-
ment is written each time a Kermit subroutine is called or returns. The ele-
ments contain the subroutine name plus (on entry) a sequence number and the
contents of registers 0 and 1 or (on exit) the character ">" and the contents
of registers 15 and 1. There is also a mechanism for tracing extra events by
inserting KTRACE calls into the source. For example,
KTRACE 0(5),REGS=5
Trace eight bytes pointed to by R5 and R5 itself.
KTRACE FOOBAR Trace eight bytes at label FOOBAR.
KTRACE 'Found it',REGS=(1,7)
Trace "Found it", R1, and R7.
The trace table is simply updated in storage, eating its own tail. It can be
found in a memory dump by locating the "eye-catcher" that says "KTRACE:", which
precedes the start, current, and end pointers for the table. The table is also
accessible interactively via the TDUMP subcommand (q.v.).
Each line in the debug log begins with a one-letter tag and a colon and con-
tains information according to the tag. The following tags are defined.
S: The text of a packet sent. Normally, it will be encoded in EBCDIC for con-
venience, but if DEBUG is set to RAW, the packet will appear exactly as
passed to or from the system, i.e., in EBCDIC for TTY or VTAMTTY lines and
in ASCII for full-screen lines.
R: The text of a packet received. The same encoding applies.
A: The AID and buffer address returned by a full-screen device along with a
read operation (three characters in all). The values should all be print-
able EBCDIC. This obsolete tag was used by TSO and MUSIC Kermits and ap-
peared only when DEBUG was set to I/O.
*: Data dumped by the optional KHDMP routine.
The following tags appear only when DEBUG is set to I/O or LONG. All values
are in hexadecimal. The meanings differ slightly according to the operating
system. For CMS, the I/O parameter list is a channel command; for TSO or ROS-
COE, the SVC 93 (TPUT/TGET) parameters; for CICS, an intermediate string
similar to channel commands. Similarly, the status data consist of the stored
CSW plus an attention interrupt indicator for CMS, but the return code from the
I/O operation for TSO, ROSCOE, CICS, and MUSIC.
a: Channel and device status after an unexpected attention interrupt.
b: I/O parameter list for recovering from a CP break-in on screen.
c: I/O parameter list for resuming normal screen operation.
d: Data transferred on the previously indicated I/O operation.
e: Status data after an I/O command has completed with an error.
g: I/O parameter list for reading from the screen buffer.
i: Status data after an I/O command has completed normally.
m: I/O parameter list for displaying text on the screen.
o: I/O parameter list for initializing the screen for transfers.
r: I/O parameter list for reading from the terminal.
w: I/O parameter list for a transparent write.
?: I/O parameter list for some other operation, such as clearing the screen.
SET DELAY
Syntax: SET DELAY number
Normally, Kermit-370 waits 10 seconds after the SEND subcommand before starting
the transfer, but this delay may be set to any non-negative value. Two DELAY
values have special meaning. When DELAY is 1, the usual two-line greeting dis-
played during protocol mode is abbreviated to a short message (the default Ker-
mit prompt with three dots...), and when DELAY is 0, the greeting is suppressed
entirely, along with the extra one-second pause for subcommands like RECEIVE,
SERVER, REMOTE, and the like.
SET EOF
Syntax: SET EOF ON or OFF
ON Scan each incoming TEXT file for the first occurrence of CTRL-Z and ig-
nore the remainder of the file (but continue decoding up to the actual
end of the file). BINARY files are not affected.
OFF Accept incoming files in their entirety. (Default.)
SET FILE CHARACTER-SET
Syntax: SET FILE CHARACTER-SET name
Specifies the name of the character set used in files stored on disk. This
setting may be superseded by an Attribute packet of an incoming file. Cur-
rently, the available names are CP037, CP273, CP275, CP277, CP278, CP280,
CP281, CP282, CP284, CP285, CP290, CP297, CP420, CP424, CP500, CP838, CP870,
CP871, CP875, CP880, CP905, CP1047, CZECH, DKOI, EBCDIC, H-EBCDIK-DASH, and
KANJI (or FUJITSU-KANJI, HITACHI-KANJI, or IBM-KANJI). The names beginning
with CP refer to IBM code pages, while DKOI is the Cyrillic standard GOST
19768-87 used in the USSR, CZECH is a character set sometimes used in Czechos-
lovakia, and EBCDIC (the default) is the traditional de facto standard EBCDIC
character set. A character set other than the default may be required by local
conventions and, if so, should be specified in the system or user INIT files.
See Table 1-1 for the allowed combinations of transfer and file character sets.
Explicitly setting this option has a side effect equivalent to issuing SET AT-
TRIBUTE ENCODING ON (q.v.).
The name KANJI is actually just an alias for the local preferred proprietary
Kanji code (Fujitsu, Hitachi, or IBM). The various Kanji character sets have
two-byte codes (DBCS), but are used with one-byte code pages (SBCS) as well.
It is normally necessary to issue two SET FILE CHARACTER-SET SUBCOMMANDS in or-
der to set up for a DBCS: first, selecting a compatible SBCS, and, second,
selecting the DBCS itself. If the current SBCS is incompatible with the
selected DBCS, a default will be chosen. This default, along with the choice
of the particular proprietary character set associated with the alias KANJI, is
chosen by the installer.
SET FILE COLLISION
Syntax: SET FILE COLLISION action
Specifies the action to take when an incoming file has the same name as an ex-
isting one. Two of the options involve choosing an alternative, unique name
similar to the one in conflict, but the details of choosing are
system-specific. Typically, the method involves adding digits to the existing
name.
APPEND The new file is appended to the old one. This option has the the
same effect as the old subcommand SET APPEND ON.
BACKUP The existing file is renamed, and the new file is given the
desired name as if no conflict had occurred.
DISCARD The incoming file is rejected by returning a "cancel file" indica-
tion on any Data packets.
OVERWRITE The existing file is overwritten with the incoming file. This is
the default for the CMS, TSO, ROSCOE, and MUSIC variants. Chang-
ing this default is a good candidate for INIT files. When COL-
LISION is set to OVERWRITE, the attributes of the new file are
determined by the current setting of FILE OVERWRITE (q.v.).
RENAME The incoming file is renamed so as not to destroy (overwrite) the
pre-existing one, and the new name is returned to the sending Ker-
mit for information purposes. This has the same effect as the old
subcommand SET WARNING ON. This is the default for the CICS
variant.
SET FILE LONGLINE
Syntax: SET FILE LONGLINE FOLD or TRUNCATE or HALT
This specifies the action to take when a received line is longer than the cur-
rent maximum record length. That length is determined by the context in a
system-specific way. Refer to the description of the RECEIVE subcommand in the
appropriate chapter for details.
FOLD Specifies that long lines are to be split into two or more records
as needed, all but the last being of the maximum length. No null
records are created when the received line is an exact multiple of
the record length. BINARY files are always considered, by defini-
tion, as a single line and, therefore, are always folded, regard-
less of the setting of this parameter. V-BINARY and D-BINARY
files, on the other hand, are reconstructed by folding at points
determined by the context within the received file, and cannot be
folded further to fit the current maximum length. Any such records
that are too long will be truncated.
TRUNCATE Specifies that long lines are to be truncated at the maximum
length. (Default.) Kermit-370 takes note of the number of such
truncations performed on a file and reports it in the STATUS mes-
sage and also treats the fact of truncation as an error when the
file transfer is complete. The file will have been transferred,
but obviously not quite intact. However, this option can be useful
for some tasks, such as stripping sequence numbers from card
images. The process is similar to that provided by the SET MARGIN
RIGHT subcommand for sending files.
HALT Specifies that a file transfer is to halt immediately if a received
line is too long. Kermit-370 then issues an error packet and stops
the transfer.
SET FILE OVERWRITE
Syntax: SET FILE OVERWRITE DEFAULT or PRESERVE
DEFAULT Specifies that the current file attribute settings are to be used
for the new file. The result is roughly the same as if the old
file, if any, were completely erased before the new file is
received. (Default.)
PRESERVE Specifies that the attributes of the file being overwritten are to
be retained and used for the new file. The result is roughly the
same as if the old files contents were deleted, and the new file
were appended to the empty stub.
SET FILE TYPE
Syntax: SET FILE TYPE type
Specifies the type of data comprising files to be sent or received. This set-
ting may be temporarily superseded by the Attribute packets for a file being
received.
TEXT Specifies ordinary text. ASCII-to-EBCDIC or EBCDIC-to-ASCII trans-
lation is performed on the data. Trailing blanks are removed, and
CRLF's are appended to outgoing records. CRLF's are used, in turn,
to determine the end of incoming records, which are padded with
blanks if necessary to fill buffers. (Default.) Note: trailing
blanks are removed from outgoing, varying-length records only if
they consist of a single blank each, or if there is a right margin
specified (q.v.). Further note: a given file is intrinsically
categorized as fixed-length or varying-length (or undefined-length)
by the file system and cannot be changed simply by setting the FILE
RECFM parameter in Kermit. Conversion between formats is a
system-specific function; see the system documentation or consult
your local support staff for details on conversion techniques.
BINARY Specifies bit-stream data. No translation is performed, no CRLF's
are added to outgoing records, and blanks are neither added nor
removed. Incoming bytes are added successively to the current
record buffer, which is written out when the current LRECL is
reached. Padding, if necessary, is done with nulls.
V-BINARY Specifies varying-length-record binary data. This type is like BI-
NARY, except that a two-byte binary prefix is added to each outgoing
record giving the number of data bytes, and incoming records are set
off by (and stripped of) their prefixes on receipt.
D-BINARY Is like V-BINARY except that the length prefixes are five-byte
ASCII-encoded decimal (right-justified with leading zeroes).
SET FOREIGN
Syntax: SET FOREIGN PREFIX string
This defines a prefix string to be added to the outgoing filespec generated by
the SEND subcommand. For example, the string might be set to "B:" to specify
output to the B disk drive on the other Kermit's system. The default is a null
string. There is also a FOREIGN SUFFIX handled in the same manner.
SET HANDSHAKE
Syntax: SET HANDSHAKE number
This defines the character, if any, that Kermit-370 should send (or cause to be
sent) immediately before reading each packet. The character is given as the
decimal of an ASCII control character, or as zero if no handshake is to be
sent. The default is 17 (XON), and any value in the range 0-31 is valid, but
13 (CR) should not be used because it is generally the end-of-packet character.
When Kermit-370 is running through a full-duplex connection (such as a
"SERIES1"), the traditional IBM handshaking is not necessary, and HANDSHAKE
should be set to 0 (as long as the other Kermit can be instructed not to expect
a handshake). Note the distinction between SET HANDSHAKE in Kermit-370 (where
it defines a character to be sent) and in many micro Kermits (where it defines
a character to be expected).
SET INCOMPLETE
Syntax: SET INCOMPLETE DISCARD or KEEP
DISCARD Specifies that incomplete files (that is, files partially received in
a transfer cancelled by the other Kermit) are to be erased. This is
the default. Note that when FILE COLLISION is APPEND, incomplete
files are never erased, lest pre-existing data be lost.
KEEP Specifies that incomplete files are to be kept.
SET LINE
Syntax: SET LINE [name]
This specifies an alternate communication line for file transfers. If the name
is omitted, the default line (the user's terminal) is used. The format of name
is, of course, system-dependent, and some variants of Kermit-370 do not support
any alternate lines. No variant currently allows Kermit-370 to CONNECT over an
alternate line.
SET MARGIN
Syntax: SET MARGIN side column
When Kermit-370 sends a text file, each line may be truncated on the left or
right (or both) at fixed column numbers. Only the text from the left margin to
the right margin (inclusive) will be sent, and any trailing blanks in the trun-
cated lines will be stripped. A value of zero for either margin disables trun-
cation on that side.
SET PROMPT
Syntax: SET PROMPT [string]
This defines the character string that Kermit-370 displays when asking for a
subcommand. The prompt may be any string of up to 20 characters. The default
is the name of the system-specific variant of Kermit-370 followed by a ">"
sign, e.g., Kermit-CMS>. If the string is omitted, normal system prompting
will occur.
SET RETRY
Syntax: SET RETRY INITIAL or PACKETS number
Kermit-370 resends its last packet after receiving a NAK or bad packet, but it
eventually gives up after repeated failures on the same packet. The limit on
retries can be set separately for the initial packet exchange (Send-Init or
server-mode command) and for ordinary packets. The default for INITIAL is 16
and for PACKETS, 5. Either limit can be set to any positive value.
SET SERVER-TIMEOUT
Syntax: SET SERVER-TIMEOUT time
This defines the time in seconds that Kermit-370 in server mode should wait for
a command before sending a NAK packet. The default is 120. A value of 0 means
that Kermit should wait indefinitely, not only in the server loop, but in all
transfers, regardless of the timeout value specified by the other Kermit. Some
variants are unable to time out in any case. Also, timeouts are not im-
plemented for any of the full-screen terminal controllers.
SET SPEED
Syntax: SET SPEED number
This determines the communication line speed assumed by Kermit-370 in calculat-
ing the optimum packet size. If the value is zero, such calculations are sup-
pressed. This option is purely informative and has no effect on actual line
speed. (Default 1200.)
SET SYSCMD
Syntax: SET SYSCMD ON or OFF
ON If the user enters a command string which is not a valid Kermit subcom-
mand, Kermit-370 will pass the string along to the host operating sys-
tem for execution. If the string is rejected by the system as well,
Kermit will report it as an invalid Kermit subcommand. Otherwise, Ker-
mit will assume the string was intended as a host command and will
simply report the completion code if non-zero.
OFF Invalid Kermit subcommands are simply rejected as such. System com-
mands may be executed, of course, but only by specifying the generic
prefix "HOST" or the appropriate system-specific prefix, such as CMS or
TSO. (Default.)
SET TABS-EXPAND
Syntax: SET TABS-EXPAND ON [list] or OFF
ON Tab characters in incoming TEXT files are replaced by one or more
blanks to bring the record size up to the next higher multiple of eight
for each tab. If tab settings other than columns 1, 9, 17, etc. are
desired, they may be specified explicitly in a list following the
keyword "ON". Items in the list may be separated by spaces or commas
and must be in strictly increasing order.
OFF Incoming tabs are retained. (Default.)
SET TAKE ECHO
Syntax: SET TAKE ECHO ON or OFF
ON Subcommands are echoed to the terminal as they are executed from a TAKE
file.
OFF Subcommands from a TAKE file are executed "silently." (Default.)
SET TAKE ERROR-ACTION
Syntax: SET TAKE ERROR-ACTION CONTINUE or HALT
CONTINUE Execution continues in a TAKE file regardless of illegal commands,
except in server mode. (This is the default.)
HALT A command error in a TAKE file causes immediate exit to Kermit sub-
command level.
SET TEST
Syntax: SET TEST ON or OFF
ON Allow setting the START-OF-PACKET and other special characters to any
value, and suppress type 1 checksum testing on received packets.
OFF Normal operation. (Default.)
SET TRANSFER CHARACTER-SET
Syntax: SET TRANSFER CHARACTER-SET name
Specifies the name of the character set used in sending or receiving files.
This setting may be superseded by an Attribute packet of an incoming file.
Currently, the available names are ASCII (the default), ARABIC, CYRILLIC,
GREEK, HEBREW, JAPAN-EUC, KATAKANA, LATIN1, LATIN2, LATIN3, THAI, and TRANS-
PARENT. There are also special aliases L1, L2, and L3 for the LATINx names.
All but JAPAN-EUC, TRANSPARENT, and ASCII represent 8-bit codes composed of a
pair of 94- or 96-character sets from the ISO registry combined with normal
definitions for the so-called C0 and C1 characters. JAPAN-EUC is a DBCS for
encoding Kanji characters, plus Roman, Greek, and Cyrillic. ASCII is the
traditional character set supported by Kermit, but one of the newer, 8-bit sets
would be preferable for most users. This option is, therefore, a good can-
didate for inclusion in the system INIT file. See Table 1-1 for the allowed
combinations of transfer and file character sets. Explicitly setting this op-
tion has a side effect equivalent to issuing SET ATTRIBUTE ENCODING ON (q.v.).
There is one exception, namely, TRANSPARENT, which sets ENCODING OFF and
replaces both translation tables with null operations, regardless of the cur-
rent nominal file character set.
The biggest drawback of the built-in tables for the various character sets is
that neither the ISO registry nor IBM defines any mapping between the C1
characters (hex 80-9F in ISO arrangements) and the characters of EBCDIC code
pages. Thus, the mappings in Kermit-370 tables are somewhat arbitrary, and fu-
ture pronouncements may suddenly invalidate some or all of those 32 mappings.
SET TRANSFER LOCKING-SHIFT
Syntax: SET TRANSFER LOCKING-SHIFT ON or OFF or FORCED
ON The Kermit locking-shift protocol is to be used in transfers to or
from cooperating partners, provided that 8th-bit quoting is enabled.
OFF The Kermit locking-shift protocol is not to be used.
FORCED The Kermit locking-shift protocol is to be used, regardless of the
cooperation of the other Kermit. The encoding uses only the locking
shifts, to the exclusion of 8th-bit quoting.
SET TTABLE
Syntax: SET TTABLE ON or OFF or KP
ON The translation that undoes the terminal controller's ASCII/EBCDIC con-
version comes from the TATOE and TETOA tables, rather than the ATOE and
ETOA tables (which are used only for translating disk files). This op-
tion has no effect when there is no translation built into the con-
troller, i.e., with SERIES1, GRAPHICS, and AEA connections.
OFF The ATOE and ETOA tables are used for all translations by Kermit-370.
(Default.)
KP Same as ON, but also establishes values in the TATOE and TETOA tables
based on IBM's corporate standard ASCII/EBCDIC translation (distinct
from the internationally accepted de facto standard).
SET 8-BIT-QUOTE
Syntax: SET 8-BIT-QUOTE char or ON or OFF
This controls whether eighth-bit prefixing is done and can be used to specify
the character to be used. This is one of only two Send-Init parameters that
cannot be SET separately for SEND and RECEIVE.
char Eighth-bit prefixing will be done using char, provided the other Kermit
agrees. The default value is an ampersand.
ON Eighth-bit prefixing will be done, provided the other Kermit explicitly
requests it (and specifies the character).
OFF Eighth-bit prefixing will not be done.
SET SEND/RECEIVE
The following parameters can be set either as SEND or RECEIVE options. As a
rule, in each pair, one is the operational value, and the other is used to
change the default for Send-Init packets received from the other Kermit and to
set up parameter values as if the other Kermit had specified them on the pre-
vious exchange. When both values are described, the operational one will be
first. For all parameters besides QUOTE, the operational value is the RECEIVE.
After a transfer, the operational values will be unchanged, but the others (as
displayed by SHOW) will reflect the parameters specified by the other Kermit.
The underlying defaults established by previous SET subcommands will still be
in effect. In the syntax descriptions, mode is SEND or RECEIVE.
END-OF-LINE
Syntax: SET mode END-OF-LINE number
RECEIVE should not be changed.
SEND may be needed to establish contact. If the other system needs packets to
be terminated by anything other than carriage return, specify the decimal value
of the desired ASCII character. number must be in the range 0-31 (decimal).
The default is 13 (CR).
PACKET-SIZE
Syntax: SET mode PACKET-SIZE number
RECEIVE defines number as the maximum length for incoming packets. The valid
range is 26-9024, but 94 is the limit for normal short-packet protocol. The
default is 80. Specifying a value greater than 94 is necessary and sufficient
to enable the long-packet protocol for transfers to Kermit-370 (provided the
other Kermit is willing). Kermit-370 will actually accept long packets in any
case, but the protocol requires that the other Kermit not send them unless
Kermit-370 asks. Raising this value from the default is a good candidate for
inclusion in INIT files. In practice, the packet size may be limited by
hardware and programming considerations. See the system-specific chapters for
details.
SEND might be needed for sending files to a minimal Kermit that neither
specifies a buffer size in the Send-Init sequence nor can accept the default
(80). It may also be used to specify the packet size for a "raw" download via
the XTYPE subcommand. This parameter has no other function and is completely
irrelevant to long packets. If the other Kermit asks for long packets,
Kermit-370 will always comply.
PAD-CHAR
Syntax: SET mode PAD-CHAR number
RECEIVE defines number as the character to be used by the other Kermit for pad-
ding packets. The character must be an ASCII control character (in the range
0-31). The default is 0 (NULL). This option is seldom useful.
SEND may be needed to establish contact if the other Kermit (or the transmis-
sion line) needs padded packets.
PADDING
Syntax: SET mode PADDING number
RECEIVE defines the number of pad characters to be used for padding packets
from the other Kermit. This number may be anywhere from 0 to 94. The default
is 0. This option is seldom useful.
SEND may be needed to establish contact if the other Kermit (or the transmis-
sion line) needs padded packets.
PARITY
Syntax: SET mode PARITY MARK or NONE
RECEIVE specifies the parity expected in the transparent-mode ASCII data
received by the mainframe from a full-screen device. Such data will typically
have either all Mark parity (seven data bits with the eighth bit set) or no
parity (eight data bits). This is typically not the same as the parity used in
communications between the protocol convertor and the terminal. Kermit-370
must know which kind of parity to expect in order to calculate checksums
properly. Since Kermit-370 does not actually verify parity, the other possible
variants (ODD, EVEN, and SPACE) are lumped together with MARK parity for the
purpose of this subcommand, which merely chooses between 7-bit and 8-bit data
transfer. The default is MARK.
SEND is also an operational value, specifying the parity to be used in con-
structing outgoing data packets on full-screen devices. NONE is the default
and is generally preferable, in that it permits binary transfers without the
need for eighth-bit prefixing, but MARK may be required in some configurations.
QUOTE
Syntax: SET mode QUOTE char
SEND indicates a printable character for prefixing (quoting) control characters
and other prefix characters. The only good reason to change this would be for
sending a file that contains many "#" characters (the normal control prefix) as
data. It must be a single character with ASCII value 33-62 or 96-126
(decimal).
RECEIVE would be needed only for talking to a crippled Kermit that uses a
non-standard quoting character, but does not admit it.
START-OF-PACKET
Syntax: SET mode START-OF-PACKET number
RECEIVE defines number as the character to be expected to mark the start of
packets from the other Kermit. The character must be an ASCII control charac-
ter (in the range 0-31). The default is 1 (SOH). This may need to be changed
to establish contact.
SEND may also need to be changed to establish contact. It defines number as
the character to be used to mark outgoing packets.
TIMEOUT
Syntax: SET mode TIMEOUT time
RECEIVE defines the time in seconds the other Kermit is to wait for a response
from Kermit-370 before resending a packet. The default is 5. A value of 0
means the other Kermit should wait indefinitely.
SEND may be needed to define the time in seconds Kermit-370 is to wait for a
response from the other Kermit in the initial packet exchange, although the
default value 0 (indefinite wait) is probably satisfactory, especially since
Kermit-370 in many cases cannot time out anyway. Specifying a non-zero value
will prevent the other Kermit from ever requesting infinite "patience" from
Kermit-370.
THE SHOW SUBCOMMAND
Syntax: SHOW [option]
The SHOW subcommand displays the values of all parameters that can be changed
with the SET subcommand, except CONTROL-CHAR, ATOE, ETOA, TATOE, and TETOA (for
those, see the TDUMP subcommand). If specified, option can be a particular
parameter or the keyword "ALL" (the default). Groups of parameters, such as
SEND, can be displayed by requesting the group name, or individual
sub-parameters can be displayed by specifying the complete name. For example,
SHOW RECEIVE EOL
will display the decimal value of the packet terminator that Kermit-370 cur-
rently expects, i.e., 13. Similarly,
SHOW FOREIGN
will display the character strings currently in use for prefix and suffix on
each outgoing filespec. When "ALL" is specified or implied, all parameters
other than the attribute switches are displayed.
THE STATUS SUBCOMMAND
Syntax: STATUS
This subcommand displays information about the previously executed subcommand.
The response will include either the appropriate error message or the message
"No errors". The initial status is "No file transfers yet". If the status
reflects an error condition, the name of the last file used (excluding TAKE
files) will be displayed as well. If the error was detected by the other Ker-
mit, the message will be "Micro aborted" followed by the text from the Error
packet. Conversely, if Kermit-370 detected the error, the text of the status
message will have constituted the error packet sent out. In any case, if the
last file transfer was cancelled (by virtue of an attribute mismatch or manual
intervention), the reason for cancellation is displayed. Also, if the error
occurred in disk I/O, any available explanatory information is displayed. Nor-
mally, the error status is altered only when a transfer-initiating subcommand
(SEND or RECEIVE) is executed, but there are several exceptions. If an invalid
subcommand is entered, the status becomes "Kermit command error", and the next
subcommand entered will reset the status. Also, in server mode every subcom-
mand is received through a transfer from the other Kermit and may affect the
status (except the STATUS subcommand itself, of course).
Other information is also included. When Kermit-370 has been forced to trun-
cate one or more records in the last RECEIVE operation (because of the current
maximum record length), the number of records truncated is reported. The
status display also includes throughput statistics for the last transfer: num-
ber of files sent, duration, number of packets, number of retries, and averages
of bytes/packet and bytes/second. These last two quantities are calculated
separately for bytes sent and received on the communication line (including
padding, if any), and the last quantity is also calculated on the basis of the
number of bytes read from or written to disk. Further, if retries were neces-
sary, Kermit-370 computes the optimum packet size assuming the retries to have
been due to sparse, Poisson-distributed bursts of noise. This is the same
heuristic optimum that Kermit-370 computes and uses as an alternative
packet-size limit when sending long packets. If TEST is set on, Kermit also
reports the maximum size attained by its storage stack since execution began.
THE STOP SUBCOMMAND
Syntax: STOP
This is not a subcommand in the usual sense. Instead, it is a command string
that can be entered on the communication line while Kermit-370 is in protocol
mode and will cause protocol mode to cease immediately. This may be useful if
the other Kermit has crashed. The word "stop" may be entered in either upper
or lower case, but it must be the only character string in the "packet" in
question. If you are using a full-screen terminal, and if other information
appears on the screen, you must clear that other text from the screen (using
CLEAR EOF) before pressing ENTER.
THE TAKE SUBCOMMAND
Syntax: TAKE filespec
Execute Kermit subcommands from the specified file, usually called a TAKE file.
The TAKE file may in turn include TAKE subcommands, and the nesting may con-
tinue to a depth of ten. If a TAKE file includes the subcommand SERVER,
however, the nesting count is saved and starts over again in server mode in
case the client Kermit should transmit a REMOTE KERMIT TAKE command. The user
has the option of seeing the subcommands echoed from the TAKE file as they are
executed and also the option of automatically exiting from a TAKE file on er-
ror. See the subcommand SET TAKE for details.
THE TDUMP SUBCOMMAND
Syntax: TDUMP table-name or NAMES or TRACE
This displays the contents of table-name. The same table can be modified using
the SET subcommand. The ATOE, ETOA, TATOE, and TETOA translation tables and
the CONTROL-CHAR prefixing selection table can presently be displayed and
changed. The NAMES table is the transaction log for the last transfer, con-
sisting of the filespec of each file sent or received, along with the size (in
Kbytes) and any error messages. If the Kermit TRACE facility is enabled, the
TRACE table may be displayed (and destroyed in the process). This table con-
tains entries for subroutine calls and returns during program execution, but
Kermit normally does not have the facility enabled. See SET DEBUG for more
details on execution tracing.
THE TYPE AND XTYPE SUBCOMMANDS
Syntax: [X]TYPE filespec
These subcommands display the named file. TYPE is effectively a synonym for
(and allows the same options as) the host system command for displaying files
at the terminal, but XTYPE performs a raw file transfer on the current com-
munication line (which need not be the terminal) according to the current CON-
TROLLER setting. Thus, XTYPE uses transparent mode if CONTROLLER is SERIES1,
GRAPHICS, or AEA. Also, it sends the data in bursts no larger than the current
SEND PACKET-SIZE. Since XTYPE is basically a modified SEND, the options al-
lowed on the filespec for SEND are also allowed for XTYPE.
THE VERSION SUBCOMMAND
Syntax: VERSION
This subcommand displays the program version number and date.
1.5. Before Connecting to the Mainframe
Several options must be set in the micro Kermit before connecting to an IBM 370
system as a line-mode device. You should set LOCAL-ECHO to ON (to indicate
half-duplex). This is the norm but not true in absolutely every case; if each
character appears twice on your terminal screen, set LOCAL-ECHO to OFF.
FLOW-CONTROL should be set to NONE, and on some systems HANDSHAKE should be set
to XON. The parity should be set according to the system's specifications. On
some micro Kermits, all of the above is done in one step using the DO IBM macro
(or SET IBM ON). Set the baud rate to correspond to the line speed.
Connecting through a full-screen device also requires that certain options be
set in the micro Kermit. You should set LOCAL-ECHO to OFF (to indicate
full-duplex). FLOW-CONTROL should be set to XON/XOFF, and HANDSHAKE should be
set to OFF. For many systems, the PARITY should be set to EVEN. Set the baud
rate to correspond to the line speed.
One exception to these rules is the case where the micro Kermit is attempting
automated file transfer, e.g., downloading several separate files from
Kermit-370 running in server mode. In fact, under those circumstances, hand-
shaking is necessary even with "SERIES1" connections, and the two Kermits must
be instructed to adopt a common handshake character (e.g., by SET HANDSHAKE 10
to Kermit-370 and SET HANDSHAKE LF to the micro).
In any case, you should make sure that either the micro Kermit or Kermit-370
will provide timeouts during file transfers (if not both). Some variants of
Kermit-370 (notably CMS) cannot provide timeouts, and you may need to set the
TIMER to ON in the micro.
When you are connecting through a protocol convertor, it is useful to know the
key sequence that causes the screen image to be repainted from the controller's
memory. In many cases, it is CTRL-V, although CTRL-G and CTRL-C are also some-
times used. In general, this sequence should be typed whenever reconnecting to
Kermit-370 after being in Kermit protocol mode (and sometimes after merely es-
caping to the local Kermit), since the local Kermit may have modified the
screen.
1.6. Trouble-shooting Protocol Converters
Many, but not all, protocol converters have transparent modes that permit Ker-
mit file transfers. The welter of competing and often incompatible communica-
tions devices would cause a major headache, except for three circumstances.
First, Kermit-370 has routines for automatically detecting which kind of front
end is controlling the current session; second, the Kermit installer is en-
couraged to tailor Kermit to force the correct choice of CONTROLLER whenever
those routines don't work properly; and, third, Kermit offers a last-resort
mode of operation that will work with almost any protocol converter. Because
of the limitations in the catch-all mode (known as FULLSCREEN mode), it is
still best to take advantage of the transparency, if any, in the protocol con-
verter, and the automatic detection routines still play an important role. It
will be instructive to outline what those routines actually do and how they can
go wrong.
Recognizing a Series/1
Although protocol converters are advertised as simulating the behavior of IBM
3270-type terminals, there generally are differences which could be used to
distinguish each type of device from the others and from real 3270-type ter-
minals. However, all that really matters to Kermit-370 is whether there is a
transparent mode available such that file transfers can be carried out. To
date, only three fundamentally different transparent modes have been reported
to Columbia, and it seems likely that no others have been (or, perhaps, ever
will be) implemented. All are supported by Kermit.
Kermit-370 recognizes these front ends automatically by making two simple
tests. The first takes advantage of one of the advanced features first im-
plemented in the Yale ASCII system and subsequently copied in many of the
devices that adopted the same transparent mode. This feature is a special 3270
data-stream order which requests a status report from the protocol converter.
Kermit sends this order and then reads the "3270 screen". If Kermit sees a
valid status report, it sets CONTROLLER to SERIES1 and stops testing.
Two catches
Obviously, the Yale status order is not implemented in most other kinds of
hardware. Thus, the order would be rejected by a non-Yale-type controller, and
that could have undesirable side effects on the hardware. However, hardware is
generally designed to be robust -- the real drawback lies in the side effects
on certain communications software (notably VTAM/TSO), which may respond badly
while trying to protect the robust hardware from illegal orders. If it proves
impossible to make the external software behave properly, the only recourse is
to modify Kermit-370 to skip the first test altogether and possibly to force
the CONTROLLER setting; this modification is described in the relevant "Beware"
file in a note dated 89/2/27.
Catch Two is that the status order is not implemented in all of the devices
that support Yale-ASCII-style transparent mode. This means that some devices
"fall through the cracks" in this procedure. A site where such devices are
used may find it expedient to modify Kermit (following the same "Beware" pat-
tern) to force the procedure to set CONTROLLER to SERIES1 (assuming there are
no other protocol converters also in use that support one of the other trans-
parent modes). A list of such devices can be found in a footnote in the Kermit
distribution file ik0aaa.hlp.
Recognizing a 3174
The second diagnostic test uses a hardware command (Read Partition Query) that
is defined by IBM, but is not implemented on all 3270-type equipment. There
is, thus, the same danger as in the first test, but the danger appears to be
slight. Indeed, both CMS and TSO allow a user program to know in advance
whether a Query is permitted. The Query response consists of one or more
structured fields, and the 3174 AEA ASCII Graphics system (the only device with
the AEA style of transparency) is easily identified by the appearance and con-
tent of a particular type of field. In fact, it is possible to tell from the
Query data whether the particular 3174 line is allowed to use the ASCII
Graphics transparency. Therefore, this test has three possible outcomes: Ker-
mit may detect a transparency-enabled 3174 line (and set CONTROLLER to AEA); it
may detect an incapable 3174 line (and set CONTROLLER to NONE); or it may
detect "none of the above" (and set CONTROLLER to GRAPHICS). Thus, aside from
the exceptions already noted, GRAPHICS simply means that the front end either
supports SAS-style transparency or none at all.
Fallback positions
What should you do when the automatic detection fails? Obviously, the first
thing is Be Prepared. Often, the misbehavior of VTAM can be halted by pressing
ENTER or PA1, so you should be sure to know how to generate a PA1 when trying
out Kermit on an unfamiliar type of protocol converter. Also, you should know
what kind of transparency to expect for the front end and verify that
Kermit-370 has, in fact, set CONTROLLER appropriately. This means checking the
list of devices in the Kermit distribution file ik0aaa.hlp. If your configura-
tion is listed as unsupported, you may be wasting your time, but the list is
not necessarily up-to-date. If your configuration is not listed at all, you
have the opportunity to be a pioneer and report your findings back to Columbia
for inclusion in future editions of the list. There are a few rules of thumb
for quickly deducing the controller type by reading the manuals for the device;
the manuals may not be specific enough, but this is clearly the easiest way of
determining whether Kermit can support a given device and which controller type
is applicable. The rules are as follows (in order of simplicity and
likelihood):
1. GRAPHICS or SERIES1 may be implied when the device has a transparent
or graphics mode described as compatible with that of a supported
device listed in ik0aaa.hlp.
2. SERIES1 is implied when the device runs the "Yale ASCII Communica-
tion System" or something with a similar name.
3. GRAPHICS is implied if the manual mentions the SAS Institute in the
context of ASCII graphics.
4. GRAPHICS is implied when output transparent data may be preceded by
a WCC (Write Control Character) and 70 (hex).
5. SERIES1 is implied when transparent data must be preceded by a WCC
and either 115D7F110005 (write-read) or 115D7F110000 (write-only).
6. GRAPHICS or SERIES1 may be implied when some of the manufacturer's
other products are listed in ik0aaa.hlp, and all are shown as being
of one type.
7. If none of the above rules apply, but the manuals describe a trans-
parent mode in detail, the device may be a totally new type. The
distribution file ik0con.hlp has hints on implementing Kermit sup-
port for the new type.
8. If nothing else works, you can probably use FULLSCREEN mode, as long
as the micro Kermit supports it.
If Kermit tries to transfer a file with the wrong CONTROLLER value, there is a
distressing possibility for the session to lock or, at least, appear to lock.
When and if this happens, be sure to connect back to the mainframe, type
"STOP", and press ENTER several times (perhaps as many as 15 times) before
taking any drastic steps like breaking the connection. "STOP" is a special es-
cape mechanism for getting out of Kermit protocol mode quickly. Kermit-370
recognizes such a request in most situations where terminal I/O is not entirely
frozen. Sometimes, apparent lock-ups are due to something as simple as incor-
rect parity settings in the micro Kermit, so always check the basic communica-
tion settings and, if necessary, experiment before trying a different CON-
TROLLER type. Also, to avoid unnecessary confusion, check for the existence of
a Kermit initialization file (possibly created by the installer) which could be
re-setting CONTROLLER after the automatic procedure has finished. Such a
re-setting is a poor idea in an initialization file, even a personal one, un-
less there is absolutely only one kind of communications equipment on your sys-
tem.
If file transfers do not work at first, it is best to do the following before
trying again:
1. Reduce the packet size to no more than 80 at both ends.
2. Enable 8th-bit quoting at both ends.
3. Set SEND PARITY MARK in Kermit-370.
If those changes do not make transfers work, the next remedial action depends
on the symptoms of failure.
- No packets exchanged and session locked up after reconnecting: change
packet characters in both directions.
- No packets exchanged, but no lockup: change packet characters or
parity.
- Always multiple retries of third or fourth packet: reduce receiving
packet size.
- Multiple retries after random number of packets: check hardware and
cables.
- Multiple retries after file-dependent number of packets: check for
equipment that intercepts one or more printable characters or reduce
the packet size.
When all else fails, you should be ready to reset CONTROLLER by hand and try
again. The change most likely to be necessary is from GRAPHICS to SERIES1.
However, it is conceivable that the installer has modified Kermit-370 at your
location to force the CONTROLLER setting from the start, in which case, you
might need to go the other way. Normally, Kermit's diagnostic procedure at
start-up takes one or two seconds (because of programmed delays), so you should
be suspicious if the Kermit prompt appears immediately after you start the
program. The only initial CONTROLLER setting that you should not change by
hand is NONE, which means that Kermit-370 has recognized a 3174 AEA line that
is not configured for file transfer (or else the Kermit installer has a warped
sense of humor).
If no amount of experimenting gets a transparent mode to work, it is time to
recheck the list of supported devices and the age of your equipment. If yours
is very old, it may require new microcode or some other software or hardware
upgrade. In any case, if your results (whether positive or negative) are not
already shown in ik0aaa.hlp, you should report them to Columbia so that others
may profit by your experience.
1.7. After Returning from Kermit-370
When Kermit-370 receives a QUIT or EXIT subcommand or finishes the subcommand
or subcommands specified in the original command string that invoked Kermit,
control is returned to the caller. Before returning, Kermit-370 closes any ac-
tive TAKE files (the EXIT or QUIT subcommand may be issued from a TAKE file).
On return, the completion code is set from the current error status according
to the codes in Table 1-4.
The error codes in Table 1-4 bear no relationship to the severity of the as-
sociated error conditions, aside from the assignment of code 0. The underlying
rationale is that the only current generic system for the treatment of comple-
tion codes is to take a non-zero code as an indication of error. Indeed, Ker-
mit returns a completion code of 0 when "error" condition 1 holds.
1.8. What's New
Below is a list of the changes in Version 4.3 of Kermit-370.
1. Compatibility with the (aging) F-level assembler.
2. Support for LATIN2, LATIN3, TRANSPARENT, CP870, CP905, and CP880, as
well as the aliases L1, L2, and L3. New alias CP1047 for EBCDIC.
3. Support for IBM 3174 ASCII Graphics mode.
-------------------------------------------------------------------------------
Code Symbol Error Message
0 NOE No errors
1 NFT No file transfers yet
2 TRC Transfer cancelled
3 USC Invalid server command
4 TIE Terminal I/O error
5 BPC Bad packet count or chksum
6 IPS Invalid packet syntax
7 IPT Invalid packet type
8 MIS Lost a packet
9 NAK Micro sent a NAK
10 ABO Micro aborted
11 FNE Invalid file name
12 FNF File not found
13 FUL Disk or file is full
14 DIE Disk I/O error
15 MOP Missing operand
16 SYS Illegal system command
17 KCE Kermit command error
18 TIM No packet received
19 RTR Records truncated
20 COM Bad communication line
21 PTY 8th-bit quote not set
22 FTS File too short
23 SOH Missing start-of-packet
24 OPT Option error on filespec
25 DSP Unable to dispose of file
Table 1-4: Error messages and codes for Kermit-370
-------------------------------------------------------------------------------
4. Improved controller detection, including local customization op-
tions.
5. Support for new unprefixed transmission of selected control charac-
ters.
6. Support for REMOTE PRINT, REMOTE MAIL, and REMOTE SUBMIT.
7. Improved error message for bad packet-size, new alias PACKET-LENGTH
for PACKET-SIZE.
8. Correct observance of FILE COLLISION for all files in a group.
9. Ignoring spurious flow-control "packets" from (for example)
MS-Kermit.
10. Support for new locking-shift Kermit protocol.
11. Support for Japanese Kanji file transfer and support for the Thai
and Arabic character sets.
12. New versions of Kermit with the interactive messages in languages
other than English.
13. New FULLSCREEN controller type.
14. New HINTS subcommand.
15. More graceful recovery from terminal I/O errors and exceptions.
16. Support for SNA LU1 3770-type devices and 8-bit, no-parity devices.
17. Optional conversion of EBCDIC printer carriage control into ASCII
control characters.
18. Support for STOP command on "dumb" 3270 terminals and PCI protocol
converters.
19. New efficiency display in STATUS report, based on SPEED setting.
20. New, uniform messages upon entering protocol mode, in the form "KER-
MIT READY TO SEND..." (or RECEIVE or SERVE).
21. 8-bit XECHO output.
22. Control prefixing for C1 controls.
23. New VERSION subcommand.
24. Improved debugging facilities.
1.9. What's Missing
Work on Kermit-370 will continue. Features that need to be improved or added
include:
- Implement file archiving.
- Implement file transfer checkpointing.
- Add SET REPEAT subcommand.
- Improve Kermit-370 operation as a local Kermit.
- Implement public server mode.
- Allow REMOTE KERMIT HELP, REMOTE KERMIT DIR, and REMOTE SET from a
micro.
- Add new SET FILE LONGLINE DISCARD option to allow multi-file transfer
to proceed past a truncation problem.
- System-specific upgrades; see the respective chapters for details.
Anyone interested in working on these or other improvements should first get in
touch with the Center for Computing Activities at Columbia University to find
out if someone else has already begun a similar project (and, if so, who).
1.10. Further Reading
Below is a list of references for some of the material in this chapter.
1. About Type: IBM's Technical Reference for 240-Pel Digitized Type,
S544-3156-02 (1989). This manual contains visual tables of many
EBCDIC code pages and a comprehensive list of character names and
acronyms.
2. IBM System/370 Reference Summary, GX20-1850-3 (1976). This refer-
ence card contains EBCDIC and ASCII character codes.
3. IBM VS Fortran Application Programming: Language Reference,
GC26-3986-1 (1982). Appendix E contains a table of EBCDIC and ASCII
characters with an implied full 256-byte translation table.
4. IBM 3174 Character Set Reference, GA27-3831-02 (1990). Chapter 5
contains visual tables of many EBCDIC code pages.
5. Info-Kermit Digest Vol. 11 #1 (1989). This issue contains draft
specifications of some Kermit protocol extensions.
6. ISO International Register of Coded Character Sets to be used with
Escape Sequences (1989). This (very large) document has complete
and unambiguous descriptions of standard coded character sets. It
can be obtained from the ECMA.
7. Kermit, A File Transfer Protocol by Frank da Cruz; Digital Press
(1987). This book contains a thorough description of the Kermit
protocol and services with copious examples.
8. Kermit distribution file ISOK7.TXT (1992). This preliminary draft
describes the new transfer protocol, including the international
character-set support.
9. Kermit News Vol. 3 #1, p.5, "Dynamic Packet Size Control" (1988).
This article describes an algorithm for optimizing Kermit throughput
in the face of line noise.
10. Kermit News #4, p.16, "International Character Sets" (1990). This
article discusses the new transfer protocol.
11. ASCII and EBCDIC Character Set and Code Issues in Systems Applica-
tions Architecture, SHARE white paper by Edwin Hart (1989). This
document, available as file SHARE REQUIRE from LISTSERV@JHUVM, lays
out general considerations for character codes and translatability.
12. Kermit distribution file LSHIFT.TXT (1991). This file describes the
new protocol extension for better compression of 8th-bit text on
7-bit channels.
2. IBM MUSIC/SP KERMIT
Program: John Chandler (Harvard/Smithsonian Center for Astrophysics);
contributions from Pierre Goyette (McGill U), Vace Kundakci and
Daphne Tzoar (Columbia U), Bob Shields (U. Maryland), Greg Small
(UC Berkeley), Clark Frazier (Harvard Bus. Sch.), Bob Bolch and
Steve Blankinship (Triangle), Andre Pirard (U. Liege)
Language: IBM/370 Assembler
Documentation: Pierre Goyette
Version: 4.3.0 (93/9/30)
Date: 1993 September
Kermit-MUSIC Capabilities At A Glance:
Local operation: No
Remote operation: Yes
Transfers text files: Yes
Transfers binary files: Yes
Wildcard send: Yes
^X/^Z interruption: Yes (through micro)
Filename collision avoidance: Yes
Can time out: Yes (line mode only)
8th-bit prefixing: Yes
Repeat count prefixing: Yes
Alternate block checks: Yes
Terminal emulation: No
Communication settings: No
Transmit BREAK: No
Packet logging: Yes
Transaction logging: Yes
Session logging: No
Raw transmit: Yes (no prompts)
Sliding window: No
Long packets: Yes
Act as server: Yes
Talk to server: Yes
Advanced server functions: Yes
Advanced commands for servers: Yes
Local file management: Yes
Handle Attribute Packets: Yes
Command/init files: Yes
Command macros: No
MUSIC Specifics of Kermit-370:
Global INIT file: SYSTEM.KERMINI
User INIT file: KERMIT.INI
Debug packet log: KERMIT.LOG
Server reply log: KERMIT.REPLY
Mail command: KERMAIL (not supported)
Print command: KERMPRT (not supported)
Submit command: KERMSUB (not supported)
Maximum packet size: 1913 (7171), 230 (TTY)
Maximum disk LRECL: 32767
Kermit-MUSIC is a member of the generic Kermit-370 family and shares most of
the features and capabilities of the group. As its name implies, Kermit-MUSIC
is the variant of Kermit-370 that runs under the MUSIC/SP operating system.
The primary documentation for Kermit-MUSIC is actually the chapter on
Kermit-370 (entitled IBM 370 Kermit), which describes general properties; the
present chapter assumes the reader is familiar with that material. Only the
details specific to MUSIC operation will be discussed here, e.g., command syn-
tax relating to the MUSIC file system or commands not offered in general by
Kermit-370.
2.1. The MUSIC/SP File System
The features of the MUSIC file system of greatest interest to Kermit users are
the format of file specifications (or filespecs) and the concept of records.
The latter is described in the Kermit-370 chapter.
The MUSIC filespec (called a Save File) takes the form
[code:]filename
The filename can be up to 17 characters in length and consists of one or more
substrings joined by periods. The substrings can contain any of the following
characters:
A through Z, 0 through 9, national characters # $ @
The only restriction is that the first substring must start with a letter or a
national character. You may also prefix the filename with a 4-digit code if
you have enough privileges. By default, the "working directory" will be set to
the your signon code. All files on this code can be accessed directly. If you
have enough privileges and wish to transfer files to or from a MUSIC code other
than your signon code, you may change the "working directory" to the new code.
MUSIC/SP allows a group of files to be specified in a single filespec by in-
cluding the special "wildcard" characters "*" and "?". A "*" matches any
string of characters (even a null string) from the current position to the end
of the field; a "?" matches any single character. It is important to remember
that the period is part of the filename. Unlike a PC, the file specification
"*" will match all filenames. Here are some examples:
*.COBOL All files of that end with .COBOL
F* All files whose names start with F.
? All files with one-character filename.
MUSIC files, like those in other IBM 370 systems, are record-oriented (see the
introduction to the Kermit-370 chapter). In particular, MUSIC files are
characterized by record format (RECFM), which may be fixed-length or
varying-length, and by maximum record length (LRECL). The size of record
blocks is irrelevant, however, because MUSIC performs the blocking and deblock-
ing operations automatically and transparently, including the spanning of
records across block boundaries. Records in MUSIC files may be up to 32767
bytes long. A third record format, namely, undefined-length, is possible in
MUSIC, but is rarely used and is not supported by Kermit-MUSIC at present.
When sending files, Kermit-MUSIC includes a date/time attribute if available.
However, any date attribute of a file received into MUSIC is merely checked for
validity and then discarded in favor of the current date.
Another file system feature of occasional interest is the means of reporting
errors. When Kermit-MUSIC encounters a disk error, it attempts to prepare an
explanatory message for inclusion in the STATUS report. The explanations can
be found in the MUSIC reference manual under the MFIO Error Codes section.
2.2. Program Operation
At startup time, Kermit-MUSIC looks for two initialization files,
*COM:SYSTEM.KERMINI and KERMIT.INI. If either of or both of these files exist,
they will be read and executed. If they do not exist on your code, Kermit will
still attempt to locate the public verion of the system file. The file
SYSTEM.KERMINI should be saved as a PUBLIC file by a systems programmer,
preferably the same code where the Kermit executable module is kept. The file
KERMIT.INI can be maintained by the user on any code.
One important distinction between Kermit-MUSIC and other Kermits is that a
program running under MUSIC/SP is unable to interrupt a read on the terminal if
you are connected through a 7171 or Series/1 protocol converter. This means
that the MUSIC variant of Kermit cannot time out after sending a packet on such
devices. The only way to time out is from the other side: typing a carriage
return to the local Kermit causing it to retransmit its last packet, or an
automatic timeout as provided by most other Kermits.
If you are connecting to MUSIC through a 7171 or Series/1 protocol converter,
then no handshaking is required since Kermit-MUSIC can control the data sent to
the micro Kermit. But if you are connected as a "TTY" terminal (through a 370x
type line), then you must enable handshaking on the micro Kermit. This is be-
cause the MUSIC/SP system will add an XON (X'11') character to the end of every
packet sent. The micro Kermit must not reply with the next packet before the
XON character is received. Usually the command "SET HANDSHAKE XON" or "SET
HANDSHAKE 17" on the micro Kermit will do this.
Interactive Operation:
To run Kermit-MUSIC interactively, invoke the program from MUSIC by typing KER-
MIT. When you see the prompt,
Kermit-MUSIC>
you may type a Kermit subcommand. When the subcommand completes, Kermit issues
another prompt. The cycle repeats until you exit from the program. For ex-
ample:
KERMIT
Kermit-MUSIC Version 4.3.0 (93/9/30)
Enter ? for a list of valid commands
Kermit-MUSIC>send foo.*
Files with prefix FOO. are sent
Kermit-MUSIC>receive test.spss
File is received and called TEST.SPSS
Kermit-MUSIC>exit
Command Line Invocation:
Kermit-MUSIC may also be invoked with a command line argument from MUSIC. The
argument is interpreted as a subcommand to be executed by Kermit after comple-
tion of the initialization. For instance:
KERMIT send test.fortran
or
KERMIT server
Kermit will exit and return to MUSIC after completing the specified subcommand.
Server mode:
Command execution in server mode is different in several respects from normal
operation. First of all, some Kermit subcommands are not allowed (see the list
of subcommands in the Kermit-370 chapter). Moreover, command errors always
terminate any active TAKE file.
2.3. Kermit-MUSIC Subcommands
Kermit-MUSIC supports all the subcommands described in the Kermit-370 chapter,
plus one more: "MUSIC", which is a synonym for the generic subcommand "HOST".
This section concentrates on the subcommands that have special form or meaning
for Kermit-MUSIC. These are ordered alphabetically. See the chapter on
Kermit-370 for further details.
THE CWD SUBCOMMAND
Syntax: CWD code
The CWD (Change Working Directory) subcommand establishes a new default code.
code may be any valid 4-digit MUSIC code. Subsequent file transfers take place
preferentially to and from the default code. The initial code is the user's
signon code.
THE DIRECTORY SUBCOMMAND
Syntax: DIRECTORY [filespec]
Under Kermit-MUSIC, the DIRECTORY subcommand is similar to the MUSIC LIBRARY
command. DIRECTORY will also display the number of lines in a file.
THE HELP SUBCOMMAND
Syntax: HELP
This subcommand displays information on the use of Kermit-MUSIC.
THE MUSIC SUBCOMMAND
Syntax: MUSIC text of command
Currently, MUSIC does not support the execution of host commands under
Kermit-MUSIC. However, the MUSIC commands LIBRARY, PURGE, RENAME, COPY, and
LIST are simulated by Kermit itself, thus providing a set of subcommands for
managing local files. The subcommand MUSIC is synonymous with the generic sub-
command HOST.
THE RECEIVE SUBCOMMAND
Syntax: RECEIVE [filespec]
The RECEIVE subcommand tells Kermit to receive a file or file group from the
other system. You should then issue a SEND subcommand to the other Kermit.
If the optional filespec is omitted, Kermit-MUSIC will use the name(s) provided
by the other Kermit. If that name is not a legal MUSIC file name, Kermit-MUSIC
will delete excess characters and will change illegal characters to dollar
signs. A filespec in the subcommand indicates what name the incoming file
should be given. Wildcards may not be used. If the optional filespec is
provided, but more than one file arrives, the first file will be stored under
the given filespec, and the remainder will be stored under their own names on
the default code.
For purposes of folding and truncation, the maximum record length for a
received file is 32767 if RECFM is V and "LRECL" if RECFM is F.
If the incoming file has the same name as an existing file, the action taken
depends on the FILE COLLISION setting. The possible settings and their mean-
ings are given in the Kermit-370 chapter. Two of the settings (BACKUP and
RENAME) require that Kermit-MUSIC change the incoming name so as not to
obliterate the pre-existing file. It attempts to find a unique name by succes-
sively modifying the original and checking for the existence of such a file at
each step. The procedure begins by truncating the filename to fifteen charac-
ters if necessary, and then appending "$0". If a file by that name exists,
Kermit then replaces the "0" with a "1". It continues in this manner up to
"9", and if an unused name cannot be found, the transfer fails.
THE SEND SUBCOMMAND
Syntax: SEND [filespec[<options>] [foreign-filespec]][, ...]
The SEND subcommand causes a file or file group to be sent from MUSIC to the
Kermit on the other system. Kermit-MUSIC will remove any code prefix for the
file header of the outgoing file. The filespec may contain the wildcard
characters "*" or "?". If it does, then all matching files will be sent. For
details on the options, see the chapter on Kermit-370. There must be no blanks
between the filespec and the options, if any.
The foreign-filespec, if any, is used for the file header of the outgoing file,
replacing the usual filename copied from the MUSIC filespec. If wildcards are
present in the filespec, then no foreign-filespec should be specified.
Trailing blanks in a text file with RECFM F are deemed superfluous and are
stripped off when Kermit-MUSIC downloads the file. In order to treat such
blanks as significant, you must convert the record format to V.
THE SET SUBCOMMAND
Syntax: SET parameter [value]
The SET subcommand establishes or modifies various parameters controlling file
transfers. The following SET parameters are available in Kermit-MUSIC, but not
in Kermit-370 in general:
DELIM Line delimiter for entering multiple commands.
DESTINATION Default Code.
FILE
LRECL Logical Record length for incoming file.
RECFM Record format for incoming files.
SET DELIM
Syntax: SET DELIM [letter]
This sets (or clears) a command line delimiter for interactive Kermit subcom-
mands. Each occurrence of the delimiter character in the command buffer read
from the terminal is treated as the start of a new subcommand. The initial
value is a blank, i.e., no delimiter, but it can be set in one of the in-
itialization files and thereby be used in parsing the initial command-line ar-
guments.
SET DESTINATION
Syntax: SET DESTINATION code
This subcommand is equivalent to the CWD subcommand (q.v.).
SET FILE LRECL
Syntax: SET FILE LRECL number
This sets the logical record length for incoming files to a number from 1 to
32767 (32K-1). This variable is used only for fixed format and binary files.
The default is 80.
SET FILE RECFM
Syntax: SET FILE RECFM option
This subcommand sets the record format to use for incoming files. Valid
options are "Fixed" and "Variable" (the default). Fixed-format records are
padded, folded, or truncated, as needed, to the current LRECL. Note: these two
formats correspond to FC and VC in standard MUSIC nomenclature. MUSIC formats
F, V, and U are not supported.
THE SPACE SUBCOMMAND
Syntax: SPACE
This subcommand displays the storage allocation on the default code. The
available space is calculated by subtracting the current allocated space from
the total space available to the user's code.
2.4. How to build an executable version of Kermit-MUSIC
Before attempting to build Kermit-MUSIC, look in the Kermit distribution under
IKMKER for an installation document, as well as "beware", help, and update
files, and read them first. They will probably contain information that is
more current and more detailed than what you see here.
Kermit-MUSIC consists at present of a few small jobs that (a) build GUPI
(Generic Update Program), (b) use GUPI to apply the current fixes to the base
code, and (c) assemble and link the updated Kermit source. The source for Ker-
mit and GUPI itself is in many pieces, some generic for Kermit-370 and some
specific to MUSIC. All the necessary pieces are sequenced in columns 73-80 so
that the numbers form a strictly increasing sequence when the pieces are cor-
rectly "pasted" together. It is important to preserve the original sequence
numbers so that updates can be applied to the source.
To create a runnable version:
1. Collect the following "ASM" files from the Kermit distribution onto
the code $KRM with RECFM FC and LRECL 80: IK0DOC, IK0MAC, IKMMAC,
IK0DEF, IK0MAI, IK0COM, IK0CMD, optionally IK0KAN, IKMUTL, IK0PRO,
IK0GUP, and IKMGUP. The files must have an extension of ".S".
2. Assemble and link the Generic Update Program GUPI, producing
$KRM:GUPI.LMOD. Before assembling the GUPI program, you must change
the IK0GUP module. Edit the file $KRM:IK0GUP.S and convert all COPY
pseudo-instructions into macro invocations. This is easily achieved
by removing the word "COPY" from in front of the copy block's name.
There are only 5 occurences of this and they are all in column 10.
The source for GUPI consists of the combination IK0MAC, IKMMAC,
IKMGUP, and IK0GUP.
3. Build the base Kermit source so that you can apply the modifications
to it. Merge the source files in the order IK0DOC, IK0MAC, IKMMAC,
IK0DEF, IK0MAI, IK0COM, IK0CMD, IKMUTL, IK0PRO, and save the result
as $KRM:KERMIT.BASE.S.
4. Apply the updates using GUPI. Note: this operation requires a
region of at least 1024K. The following command will apply the
fixes to the source module $KRM:KERMIT.BASE.S using the update file
$KRM:IKMKER.UPD and save the updated source in $KRM:KERMIT.S.
GUPI $KRM:KERMIT.BASE.S $KRM:IKMKER.UPD $KRM:KERMIT.S
5. Assemble the Kermit source and link the object deck together with
MATCH and MFINDX to produce $KRM:KERMIT.LMOD.
6. Save the following jobstream in the file $KRM:KERMIT This will ex-
ecute the KERMIT program with the proper system parameters.
/SYS NOPRINT,REGION=256
/FILE LMOD N($KRM:KERMIT.LMOD) SHR
/LOAD XMON
KERMIT
7. Kermit-MUSIC requries the LSCAN privilege since it does a save
library scan directly. You must modify either the system module
LOOKUP or the macro invoked by LOOKUP called $MCM:USERTBL.M. Add
the line
FILNAM '$KRM:KERMIT',(LSCAN,0)
to either of the two files. Reassemble the module LOOKUP and make
sure that the new object deck is used when rebuilding the nucleus.
If you do not give Kermit this privilege, the program will abend on
user codes that do not have LSCAN.
Since Kermit-MUSIC drives the I/O directly for both "TTY" and "SERIES1"
devices, your site's ASCII/EBCDIC translation tables will not affect
Kermit-MUSIC in file transfer mode.
2.5. What's New
Below is a list of the MUSIC-specific updates in Version 4.3.0 of Kermit-MUSIC
added since the previous major release, Version 4.2, in March of 1990. For a
list of generic additions, see the Kermit-370 chapter.
1. Multiple Kermit subcommands specifiable on the MUSIC command line if
the INIT file defines a delimiter.
2. Support for time tags for files being sent.
2.6. What's Missing
Work on Kermit-MUSIC will continue. Features that need to be improved or added
include:
- Allow timeouts so Kermit-MUSIC does not wait forever if a packet does
not arrive in a timely fashion. This is not possible under MUSIC at
present for I/O through a protocol converter.
- Implement file archiving.
- Support execution of Music commands from Kermit or the remote Kermit.
- Add a SET REPEAT subcommand.
- Support subdirectories and userids longer than four characters.
There is already an update for this support, but it requires MUSIC
2.4 and has not been tested yet. See the "beware" file for the
latest information.
Anyone interested in working on these or other improvements should first get in
touch with the Center for Computing Activities at Columbia University to find
out if someone else has already begun a similar project (and, if so, who).
Index
3174 1, 5
3708 5
Alternate lines 7
Appending 6
Arabic 1, 8
ASCII-to-EBCDIC 5
Attributes. See File at-
tributes
Batch jobs 3
Binary files 1, 4, 6, 7
Blanks
preserving trailing 7, 13
stripping 1, 7
trailing 1, 7
BLKSIZE 1
Block check 5
Cancelling a file transfer 4
Character sets 1, 6, 8
CICS 6
CMS 6
Code pages 1
See also Character sets
Collision. See Filename col-
lision
Command echoing 7, 9
Command prefix 3, 4, 7
Completion codes 10
See also Error codes
Control characters 5, 9
Controller 5
CRLF 1, 7
CSW 6
CWD 13
Cyrillic 1, 6, 8
Debugging 5
Default Code 12, 13
DIRECTORY 13
Discarding files 6, 7, 11
See also DELETE
DOS-4 1
Dumping storage 5
EBCDIC-to-ASCII 5
ECHO 3
See also Command echo-
ing
Eighth-bit prefix 8
Electronic mail 3
End of file 6
Error codes 10, 12
Extended ASCII 5
File attributes 1, 5, 9
File disposition 3
File renaming 6
File truncation 6
Filename collision 6, 13
Flow control 9, 12
Folding 4, 6, 13
Foreign 3, 7
Front end 1
Full screen 4, 9
GET 3
GIVE 3
Greek 1, 8
Handshake 7, 9, 12
Hebrew 1, 8
HELP 13
Host commands 4, 7
IBM 1, 12
Incomplete files 4, 7
Initialization files 1, 2,
3, 6, 8, 12, 14
Kanji 1, 6, 8
Katakana 1, 8
Languages 1
Line delimiter 13
Local 3
LOCAL-ECHO 9
Long packets 4, 8, 9
LRECL 1, 7
Mail 3
See also Electronic
mail
Margins 7
MTS 1
MUSIC 6
MUSIC/SP 12
Optimum packet size 4, 7
Overwriting files 6
See also Filename col-
lision
Packet size 4, 8
Parity 8, 9
Prefix. See Command,
Eighth-bit, Foreign
Prefixing 5
Printing files 3
Prompt 7
Quote. See Prefix
Raw transmission 3, 9
RECEIVE 3, 4, 13
RECFM 1
Records 1
Remote 3
RENAME 6
Renaming files 6
See also File renaming
ROSCOE 6
Screen refresh 9
SEND 3, 4, 13
SEND delay 6
Series/1 1, 5, 12
SERVER 4
SET 4, 13
SHOW 9
SNA 1, 5
SPACE 13
STATUS 9
STOP 9
Stripping blanks. See Blanks
Subcommand prefix. See Command
prefix
Submitting jobs 3
See also Batch jobs
Tabs 7
TAKE 9
TDUMP 9
TEST 7
TGET 6
Thai 1
Timeout 7, 9
TPUT 6
Tracing execution 5, 9
Trailing blanks. See Blanks
Transaction log 4, 9
Translation 1, 2, 8, 14
Translation tables 1, 3, 8
Transparent mode 3, 9
Truncation 4, 6, 13
See also File trun-
cation
TSO 6
TTY 1, 5, 9, 12
Type 4
Warning 6
Wildcards 12, 13
XECHO 3