mrbuffer/src/main.S
2018-01-31 23:47:06 -05:00

176 lines
2.1 KiB
ArmAsm

rel
typ $B3
dsk main.l
; ensure 16-bit mode (unnecessary?)
clc
xce
rep #$20
phk
plb
; half bank for accumulator, you don't want to toggle them on then back off, right?
sep #$30
; toggle the softswitches; they don't take any values. some are only triggered
; by writes, $C054 can be triggered by a read
stal $00C000 ; disable 80 column store?
stal $00C00C ; disable 80 column hardware?!
stal $00C050 ; set standard apple ii gfx mode
stal $00C051 ; select text mode only. "only"?
ldal $00C054 ; select text page 1 (there are 2)
ldal $00C056 ; select "low res" graphics
* rep #$30
; show the current char on screen
; read keyboard then hit strobe to reset
ldx #0
eloop ldal $00C000
skip stal $000400,X
clc
bit %1
jsr handlekey
ldal $00C010
jmp eloop
handlekey cmp #$1088
beq left
cmp #$1095
beq right
outkey rts
left clc
cpx #0
beq outkey
dex
rts
right clc
cpx #39
beq outkey
inx
rts
; working text blit
* ldx #hithere+2 ; strl, first two bytes are strlen, # denotes immediate addr val
* ldy #$0400 ; start of text buffer on 00
* ldal hithere
* dec
* mvn $02, $00
* brk
; Important locations
SPEAKER equ $E0C030
PRODOS16 equ $E100A8
jsl PRODOS16
; This exit code is "device busy", why is it the only one
; that works?!
da $29
adrl QP
bcs ERROR
ERROR brk
QP adrl $0000
da $00
hithere strl "this was excruciating"
brkboi brk