emailler/client/uthernet/c700_rom.s

49 lines
765 B
ArmAsm

.include "../inc/common.i"
.include "../inc/a2keycodes.i"
.import print_a
.import print_cr
pptr=$04 ;temp pointer for printing from
.segment "C700"
;Autostart 'signature' bytes - make this rom look like a Disk ][ controller card
.byte $c9,$20,$c9,$00,$c9,$03,$c9,$3c
ldax #hello_world
jsr print
rts
sta $cfff ;turn of all other expansion ROMs
sta $c0f4 ;set bank
ldax #$c800
jsr print
rts
print:
sta pptr
stx pptr + 1
@print_loop:
ldy #0
lda (pptr),y
beq @done_print
jsr print_a
inc pptr
bne @print_loop
inc pptr+1
bne @print_loop ;if we ever get to $ffff, we've probably gone far enough ;-)
@done_print:
rts
hello_world:
.byte "hello from autostart firmware land!",13,0