[Coco] Detecting CoCo 1 versus CoCo 2

[RETRO Innovations]

On 10/17/2024 2:23 PM, Sean Conner via Coco wrote:
> It was thus said that the Great Juan Castro via Coco once stated:
>>>  From Darren Atkison:
>>> The audio MUX on the CoCo 1 is bi-directional, but the integrated
>>> DAC/MUX on the CoCo 2 is uni-directional. There is a test you can do
>>> where you toggle the single-bit sound output and check to see if the
>>> cassette input level changes to match. If it does change then it's a
>>> CoCo 1.
>> Oh man, if anybody here has that code I'd like to see it.
>    If I understand the explanation right, then something like:
>
> 	lda	$FF22
> 	ora	#2
> 	sta	$FF22		; enable single bit output
> 	lda	$FF20
> 	bita	#1		; check cassette data input
> 	beq	coco2		; if not 1, then CoCo2
>
> would work.  In BASIC, this would be:
>
> 	10 A = PEEK&HFF22
> 	20 A = A OR 2
> 	30 POKE&HFF22,A
> 	40 A = PEEK&HFF20
> 	50 A = A AND 1
> 	60 IF A == 0 THEN PRINT "COCO2"
>
>    -spc
>
>
Don't you need to set the DDR and the port and make sure the state is
different from the current cassette in state?

JIm



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