UNIX 6th Ed. - /usr/source/s3/mesg.s

   1: .globl  mesg
   2: 
   3: / usage:
   4: /   jsr r5,mesg
   5: /       <string ending in \0>
   6: /      .even
   7: /   ...
   8: /
   9: / string is output onto $1
  10: /
  11: 
  12: mesg:
  13:         mov     r0,-(sp)
  14:         mov     r5,r0
  15:         mov     r5,0f
  16: 1:
  17:         tstb    (r5)+
  18:         bne     1b
  19:         sub     r5,r0
  20:         com     r0
  21:         mov     r0,0f+2
  22:         mov     $1,r0
  23:         sys     0; 9f
  24: .data
  25: 9:
  26:         sys     write; 0:..; ..
  27: .text
  28:         inc     r5
  29:         bic     $1,r5
  30:         mov     (sp)+,r0
  31:         rts     r5

Defined functions