Hi!
Laoo, on atariage forums you can read as below:
This did not detect my stereo Pokey cartridge. You should probably look for Pokeys in d5xx as well.
Steve
so, as You see there is other hardware solutions for Stereo-POKEY for 8-bit ATARI :)
I did't know about this solution, before I read those post on Atari Age forum.
The IRQ method, is probably don't work for the cartridge version of Stereo-Upgrade.
But as You notice before I think that the "IRQ" detection is the best way to detect the standard stereo upgrage (second POKEY located at D21x area)
on AtariAge forum, Raster show the own code for second Pokey detection:
pokey1 equ $d200
pokey2 equ $d210
STEREODETECTION
lda pokey1+$09
beq iss2 ;0 => last key L
;no last key L
lda pokey2+$09
beq issyes;0 on second POKEY KEY reg => stereo
issno
lda #0
rts
iss2
ldy #7
iss3
lda pokey2,y;POT regs
bne issno ;some one is not zero
dey
bpl iss3
issyes
lda #1
rts
and here is, my old stereo detect routine (based od IRQ), this procedure was published a long time ago in our "Barymag" magazine.
* -----------------------------
* |second POKEY detect routine|
* | answer in A register: |
* |$00 - absent $80 - present |
* -----------------------------
* | code & idea: Seban/SLIGHT |
* |-+* (c) 1995,96 Slight! *+-|
* -----------------------------
st sei
inc $d40e
lda #$03
sta $d21f
sta $d210
ldx #$00
stx $d211
inx
stx $d21e
ldx $d40b
bne *-3
stx $d219
w ldx $d40b
bmi ext
lda #$01
bit $d20e
bne w
ext lda $10
sta $d20e
dec $d40e
cli
txa
rts
greetz
Seban/SLIGHT
