title   ksend/mac   sending unit
        cseg
        ;
        ;
        extrn   recptr,recbuf,rplus,mjump
        extrn   spaket,rpaket,screen
        extrn   rplus,sinit,state,byte,n,r
        extrn   rpack,spack,abort,acsum,flush
        extrn   fcb,writnx,open,rinit,close
        extrn   lrecl,readnx,buffil,filnam,tstack
        public  s_init,s_file,s_open,s_break
        public  s_data,s_eof
        ;
        len     equ     0
        seq     equ     1
        type    equ     2
        data    equ     3
        quote   equ     '#'
        _a      equ     1
        _c      equ     2
        _r      equ     3
        _rf     equ     4
        _rd     equ     5
        _s      equ     6
        _sf     equ     7
        _sd     equ     8
        _se     equ     9
        _sb     equ     10
        _o      equ     11
        ;
        ;
        subttl  macros used in this module
        ;
        ;prmes  to display messages
        ;
        prmes   macro   lab
        .xlist
        extrn   m_&lab,l_&lab
        push    hl
        push    bc
        ld      hl,m_&lab
        ld      bc,(l_&lab)
        ld      c,13
        ld      a,9
        rst     8
        pop     bc
        pop     hl
        .list
        endm
        ;movb
        ;
        movb    macro   value,loc
        .xlist
        push    af
        ld      a,value
        ld      (loc),a
        pop     af
        .list
        endm
        ;
        ;blmov
        ;
        blmov   macro   source,dest,len
        .xlist
        local   $1,$2
        push    hl
        push    bc
        push    de
        ld      hl,source
        ld      de,dest
        ld      a,(len)
        cp      0
        jr      nz,$1
        ld      b,1
        ld      c,0
        jp      $2
        $1:
        ld      b,0
        ld      c,a
        $2:
        ldir
        pop     de
        pop     bc
        pop     hl
        .list
        endm
        ;
        ;fack   to format an ack paket
        ;
        f_ack   macro
        .xlist
        ld      (iy+len),3
        ld      a,(n)
        add     a,' '
        ld      (iy+seq),a
        ld      (iy+type),'Y'
        ld      hl,spaket
        call    acsum
        .list
        endm
        ;
        ;nplus
        ;
        nplus   macro
        .xlist
        ld      hl,n
        inc     (hl)
        res     6,(hl)
        movb    0,r
        .list
        endm
        ;
        subttl  open file (pseudo-state, precedes send_init)
        page
        ;
        ;       open file
        ;
        s_open:
                call    open            ;open file (assume fcb set)
                movb    _s,state        ;state = send_init
                movb    0,n             ;packet number to 0
                movb    0,r             ;reset retry count
                call    flush           ;clear comm buffers
                jp      mjump           ;and back
        subttl  send initialisation routine
        page
        ;
        ;       send init parameters
        ;
        s_init:
                ld      ix,rpaket
                ld      iy,spaket
                ld      (iy+len),12     ;length of init packet
                ld      (iy+type),'S'   ;type send init
                ld      a,(n)           ;current packet number
                add     a,' '           ;make printable
                ld      (iy+seq),a      ;into packet
                movb    12,byte         ;number of bytes to move
                blmov   rinit,spaket+data,byte
                ld      hl,spaket       ;to point correctly
                call    acsum           ;compute checksum
                call    spack           ;and send packet
                ld      a,(hl)          ;get paket length and fix it
                sub     ' '             ;because there might be a retry
                ld      (hl),a          ;save back
                call    rpack           ;get answer
                jp      c,rplus         ;no good
                call    tstack          ;was it a good ack ?
                jp      c,rplus         ;no, send it again
                blmov   rpaket+data,sinit,byte
                                        ;move parameters to keep
                ld      hl,sinit+4      ;address of eol
                res     5,(hl)          ;sub 32 to get real eol
                ld      hl,sinit        ;maxlen to send
                res     5,(hl)          ;sub 32
                nplus                   ;increment packet count
                movb    _sf,state       ;state = send file header
                jp      mjump           ;and back
        subttl  send file header information
        page
        ;
        ;       send file header
        ;
        s_file:
                ld      hl,filnam+1     ;where the filame start
                ld      a,(filnam)      ;it's length
                ld      b,a             ;store len in b
                ld      a,'/'           ;byte to look for
        s1:
                cp      (hl)            ;is this a '/' ?
                jp      z,s2            ;yes change it t '.'
                inc     hl              ;advance pointer
                djnz    s1              ;and check next byte
                jp      s3              ;there was no '/'
        s2:
                ld      a,'.'           ;a dot to normalize filename
                ld      (hl),a          ;in place
        s3:
                ld      (iy+type),'F'   ;of type file header
                ld      a,(n)           ;get packet count
                add     a,' '           ;make printable
                ld      (iy+seq),a      ;insert in spacket
                blmov   filnam+1,spaket+data,filnam
                                        ;put in filename
                ld      a,(filnam)      ;get filename length
                add     a,3             ;add len,seq,type
                ld      (iy+len),a      ;set in spacket
                ld      hl,spaket       ;hl to point correctly
                call    acsum           ;compute checksum
                call    spack           ;send it
                ld      a,(hl)          ;get paket length and fix it
                sub     ' '             ;because there might be a retry
                ld      (hl),a          ;save back in spaket
                call    rpack           ;get answer
                jp      c,rplus         ;no good
                call    tstack          ;was it a good ack ?
                jp      c,rplus         ;no
                nplus                   ;update packet count
 
                call    buffil          ;get a bufferfull
                jp      c,s_eof         ;it was the end of file
                movb    _sd,state       ;state = send_data
                jp      mjump           ;return
        subttl  send data from file
        page
        ;
        ;       send data
        ;
        s_data:
                ld      (iy+type),'D'   ;data packet
                ld      a,(n)           ;packet number
                add     a,' '           ;make printable
                ld      (iy+seq),a      ;into packet
                ld      hl,spaket       ;hl point correctly
                call    acsum           ;compute checksum
                call    spack           ;send it
                ld      a,(hl)          ;get length to fix it in case
                sub     ' '             ; of a bad ack
                ld      (hl),a          ;save back in spaket
                call    rpack           ;get answer
                jp      c,rplus         ;no good
                call    tstack          ;a good ack ?
                jp      c,rplus         ;nope...
                nplus                   ;yes, update packet count
                call    buffil          ;get next packet ready
                jp      c,s_eof         ;we reach the eof
                jp      mjump           ;and back
        subttl  send end of file
        page
        ;
        ;       send end of file
        ;
        s_eof:
                movb    _se,state       ;might not be done
                ld      (iy+type),'Z'   ;eof in spacket
                ld      (iy+len),3      ;length
                ld      a,(n)           ;packet number
                add     a,' '           ;make printable
                ld      (iy+seq),a      ;into packet
                ld      hl,spaket       ;to point correctly
                call    acsum           ;compute checksum
                call    spack           ;send packet
                ld      a,(hl)          ;get paket length
                sub     ' '             ;and fix it
                ld      (hl),a          ;back in spaket
                call    rpack           ;get answer
                jp      c,rplus         ;no good
                call    tstack          ;test for good ack
                jp      c,rplus         ;no good
                nplus                   ;good, update packet count
                movb    _sb,state       ;state = break transmission
                jp      mjump           ;and back
        subttl  send break transmission
        page
        ;
        ;       send break transmission
        ;
        s_break:
                ld      (iy+type),'B'   ;in spaket, set type
                ld      (iy+len),3      ;and length
                ld      a,(n)           ;current packet number
                add     a,' '           ;make printable
                ld      (iy+seq),a      ;store in spaket
                ld      hl,spaket       ;hl to point correctly
                call    acsum           ;compute checksum
                call    spack           ;send packet
                ld      a,(hl)          ;get paket length and fix it
                sub     ' '             ;there might be a retry
                ld      (hl),a          ;save back in spaket
                call    rpack           ;get answer
                jp      c,rplus         ;no good
                call    tstack          ;check if correct ack
                jp      c,rplus         ;no, send again
                movb    _c,state        ;complete
                jp      mjump           ;FIN...
                end