[Coco] DAC sound output and keyboard input

[Nick Marentes]

On 20/06/2014 10:17 PM, Mark McDougall wrote:
> On 20/06/2014 12:25 AM, John W. Linville wrote:
>
>> Bit 7 is JOYIN (the comparator output), used to read the joysticks
>> (via successive approximation ADC).  You probably should mask that
>> when you are doing your "any key" check.
>
> Doh! I don't know why I didn't realise this, since I've been staring 
> at the Coco keyboard matrix for weeks now. In my defence, I'm 
> intimately more familiar with the TRS-8 Model I matrix, in which rows 
> are read rather than columns (and you can get all the arrows keys and 
> spacebar in a single read!)
>
> All sorted now, thanks!
>
> Regards,
>

As I said, no need for 6-bit DAC sound if you're only emulating the 
Apple II 1-bit sound.

Maybe use the 6-bit DAC to add joystick control to the game? To dig, 
with the fire button held down, move the joystick left or right to dig 
left or right. Did the Apple II version supprt Apple joysticks?

I could never use the cursor arrow key cluster for player control. I 
always preferred the TRS-80 Model 1 (and CoCo 1/2) arrow key positions 
for game control.

Nick