51 lines
1.5 KiB
NASM
51 lines
1.5 KiB
NASM
|
|
; Hello World for Philips Videopac (Magnavox Odyssey 2)
|
|
; by Frog ( https://github.com/petersobolev )
|
|
; 25 July 2016
|
|
|
|
cpu 8048
|
|
org 400h
|
|
|
|
; interrupt vectors
|
|
jmp 02C3h ; selectgame (RESET)
|
|
jmp 0009h ; irq
|
|
jmp timer ; timer
|
|
jmp 001Ah ; vsyncirq
|
|
jmp start ; after selectgame
|
|
jmp 0044h ; soundirq
|
|
|
|
timer:
|
|
ret ; no timer needed
|
|
|
|
|
|
start:
|
|
|
|
call 011Ch ; gfxoff
|
|
|
|
mov r0,#010h ; pointer in VDC - which char to display (one of 12)
|
|
mov r3,#40 ; x
|
|
mov r4,#100 ; y
|
|
mov r1,#hellostr & 0ffh ; string to print (should be on same 255 bytes page)
|
|
|
|
mov r2,#11 ; string length
|
|
|
|
nextchar:
|
|
mov a,r1
|
|
movp a,@a ; get char located at @r1
|
|
mov r5,a
|
|
inc r1 ; inc addr of char
|
|
mov r6,#0eh ; white color
|
|
call 03EAh ; printchar bios subroutine (increases r0, r3)
|
|
djnz r2,nextchar
|
|
|
|
call 0127h ; gfxon (show what is written to VDC)
|
|
|
|
|
|
loop:
|
|
jmp loop ; just wait and do nothing
|
|
|
|
; 'HELLO WORLD' (ascii not supported by assembler)
|
|
hellostr:
|
|
db 01dh, 012h, 00eh, 00eh, 017h, 00ch, 011h, 017h, 013h, 00eh, 01ah
|
|
|