m68k

intin equ   8                   ; setup some constants
ptsin equ   12
colbit0  equ   24
colbit1  equ   26
colbit2  equ   28
colbit3  equ   30
lstlin   equ   32
lnmask   equ   34
wmode equ   36
x1 equ   38
y1 equ   40
x2 equ   42
y2 equ   44
init  equ   $a000
setpix   equ   $a001
getpix   equ   $a002
drwlin   equ   $a003

start:
   jsr   initialize

   dc.w  init                   ; call line a init

   move.w   #1,colbit0(a0)      ; setup arguments to draw line
   move.w   #1,colbit1(a0)
   move.w   #1,colbit2(a0)
   move.w   #1,colbit3(a0)
   move.w   #0,lstlin(a0)
   move.w   #$ffff,lnmask(a0)
   move.w   #0,wmode(a0)
   move.w   #0,x1(a0)
   move.w   #0,y1(a0)
   move.w   #100,x2(a0)
   move.w   #100,y2(a0)
   dc.w  drwlin                 ;call line a draw line

   move.w   #7,-(a7)
   trap  #1                     ;wait keypress
   addq.l   #2,a7
   jsr   restore
   clr.l    -(a7)               ;call gemdos
   trap  #1

initialize:                     ; go into super user mode
   clr.l -(a7)
   move.w #32,-(a7)
   trap #1
   addq.l #6,a7
   move.l d0,oldstack
   rts

restore:                        ; go back into user mode
   move.l oldstack,-(a7)
   move.w #32,-(a7)
   trap #1
   addq.l #6,a7
   rts

oldstack dc.l 0

; comment at eof