2019-12-18 01:30:42 +00:00
|
|
|
|
2019-12-19 01:06:00 +00:00
|
|
|
include "cartheader.dasm"
|
|
|
|
|
|
2019-12-18 01:30:42 +00:00
|
|
|
; program start
|
2019-12-19 01:06:00 +00:00
|
|
|
Temp equ $03
|
2019-12-18 01:30:42 +00:00
|
|
|
Start
|
|
|
|
|
sei ; turn off interrupts
|
|
|
|
|
ldy #0
|
|
|
|
|
sty $d020 ; reset border color
|
|
|
|
|
Loop
|
|
|
|
|
lda Message,y ; load message byte
|
|
|
|
|
beq EOM ; 0 = end of string
|
|
|
|
|
clc
|
|
|
|
|
adc #$c0 ; + 192
|
|
|
|
|
sta $400+41,y ; store to screen
|
|
|
|
|
iny
|
|
|
|
|
bne Loop ; next character
|
|
|
|
|
EOM
|
|
|
|
|
Wait1
|
|
|
|
|
lda $d011
|
|
|
|
|
bmi Wait1 ; wait for line < 256
|
|
|
|
|
Wait2
|
|
|
|
|
lda $d012 ; get current scanline
|
|
|
|
|
Wait3
|
|
|
|
|
cmp $d012
|
|
|
|
|
beq Wait3 ; wait for scanline to change
|
|
|
|
|
lsr
|
|
|
|
|
lsr
|
|
|
|
|
clc
|
|
|
|
|
adc Temp
|
|
|
|
|
sta $d020 ; set border color
|
|
|
|
|
lda $d011 ; get status bits
|
|
|
|
|
bpl Wait2 ; repeat until line >= 256
|
|
|
|
|
sty $d020 ; reset border color
|
|
|
|
|
dec Temp ; scroll colors
|
|
|
|
|
jmp Wait1 ; endless loop
|
|
|
|
|
Message
|
|
|
|
|
; PETSCII - http://sta.c64.org/cbm64pet.html
|
|
|
|
|
byte "HELLO`WORLDa"
|
|
|
|
|
byte 0
|
