$1 rem Use this BASIC program on the PE7500 if you have the printable file 
2 rem pe7500.boo already on the PE7500 to convert it to an executable
3 rem file.  This program takes about 7 minutes to run on a PE7500 with
4 rem a hard disk.
5 rem  Bill Catchings, June 1984
6 rem  Columbia University Center for Computing Activities
7 rem  Converted to Perkin-Elemer Series 7000 (7500) Basic from IBM-PC Basic
8 rem  Runs under Idris (1.81) By Chris Lent 28-NOV-1986
9 print "PE7BOO.BAS Version 2.3a (Derived from IBM-PC MSBPCT.BAS)"
10  t$= clk$ 				:rem  Save the time.
20  defint a-z				:rem  Integer to gain some speed.
30  n$= chr$ ( 0)
40  z= asc ("0")
50  t= asc ("~")-z
60  def fnuchr%(a$)= asc (a$)-z
65 k$="pe7ker.boo": rem filename case significant
70  open "i",# 1,k$:rem filename case significant
80  f$="hello there"
100 linput # 1,f$	:rem Is this the right file?
101 rem remove nasty characters in filename 
102 h$=""
103 for i= 1 to  len (f$)
105  g$= mid$ (f$,i, 1)
106  if g$>" " and g$<="~" then h$=h$+g$
107 next i
108 f$=h$
109  print f$:rem show user filename
110  if  len (f$)> 20 then  goto 900 
120  open "o",# 2,f$
130  print "Outputting to "+f$
200  if  eof ( 1) then  goto 800 	:rem  Exit nicely on end of file.
210  linput # 1,x$			:rem  Get a line.
220  y$=""				:rem  Clear the output buffer.
230  goto 400 
300  print # 2,y$;
310  goto 200 				:rem  Get another line.
400  if len (x$)< 2 goto 300 		:rem  Is the input buffer empty?
410  a=fnuchr%(x$)
420  if a=t then  goto 700 		:rem  Null repeat character?
430  if  len (x$)< 3 goto 300 		:rem  Is the input buffer empty?
440  q$= mid$ (x$, 2, 3)		:rem  Get the quadruplet to decode.
450  x$= mid$ (x$, 5)
460  b=fnuchr%(q$)
470  q$= mid$ (q$, 2)
480  c=fnuchr%(q$)
490  q$= mid$ (q$, 2)
500  d=fnuchr%(q$)
600  y$=y$+ chr$ (((a* 4)+(b\ 16)) and  255):rem  Decode the quad.
610  y$=y$+ chr$ (((b* 16)+(c\ 4)) and  255)
620  y$=y$+ chr$ (((c* 64)+d) and  255)
630  goto 400 				:rem  Get another quad.
700  x$= mid$ (x$, 2)			:rem  Expand the nulls.
710  r=fnuchr%(x$)			:rem  Get the number of nulls.
715  print " Null: ",r
720  x$= mid$ (x$, 2)
725  print # 2,y$;
730  for i= 1 to r
740  print # 2, chr$ ( 0);
750  next i
760  rem
770  y$=""				:rem  Clear the output buffer.
780  goto 400 
800  print "Processing complete, elapsed time: "+t$+" to "+ clk$ 
810  print "Output in "+f$
820  close # 1,# 2
830  goto 9999 
900  print "?The version of the MSKERMIT.BOO file is incorrect"
910  goto 820 
9999 end