The headline for today is that the Liber809... well, SHE'S ALIVE! This short video shows it hooked up to the Atari XEGS and being fired up. The TV shows colors being cycled and the sound coming from the speaker. The 6809 assembly that makes this happen is below.
So that's where I am now. The next steps are:
- Expand on the test code a bit and gain confidence that things are working well.
- Get several actual prototype boards made so I can get away from using the Frankenstein wire wrap. Gary's working on this.
- Learn more about the Atari 8 bit hardware to see what other cool things can be done.
- Come up with a plan to bring NitrOS-9 to the platform.
org $C000
DelayQuick
clra
d@
deca
bne d@
rts
DelayLong
ldd #$4000
d@
subd #$0001
bne d@
rts
ClearIO
clrb
loop
ldx #$D000
clr b,x
ldx #$D200
clr b,x
ldx #$D300
clr b,x
ldx #$D400
clr b,x
decb
bne loop
rts
SetupPOKEY
lda #3
sta $D20F ; set POKEY to active
rts
SetupSound
lda #$A0
sta $D200
lda #$A1
sta $D202 ; set audf1 and audf2
lda #$A8
sta $D201
sta $D203 ; set audc1 and audc2
rts
fill $FF,$E000-*
SWI3Vct
rti
SWI2Vct
rti
FIRQVct
rti
IRQVct
rti
SWIVct
rti
NMIVct
rti
RESETVct
orcc #$50
lds #$2000
lbsr ClearIO
lbsr DelayQuick
lbsr SetupPOKEY
lbsr SetupSound
clra
xxx
sta $D01A
inca
pshs a
lbsr DelayLong
puls a
bra xxx
wait
jmp wait
* 6809 Vectors
fill $FF,$FFF0-*
fdb $0000 Reserved
fdb SWI3Vct SWI3
fdb SWI2Vct SWI2
fdb FIRQVct /FIRQ
fdb IRQVct /IRQ
fdb SWIVct SWI
fdb NMIVct /NMI
fdb RESETVct /RESET
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