Making CD32 Controls for A1200

[3vilc]

Hi all,
I have a SurfSquirrel on my A1200 and some CD32 games I am trying to play.  According to A1200 joystick port pinouts the port allows 3 different fire buttons, but a CD32 controller appears to have more that 3 buttons.  What I am trying to do is make an arcade panel that will be compatible with the cd32 controller.  Is it possible or does the cd32 controller have hardware inside to allow it to work with more buttons.  I am currently about to construct the panel with 3 buttons connected to the 3 A1200 inputs, will this work or do I need all 6? buttons of the cd32 controller to play cd32 games?

Any help would be appreciated
Thanks,
Clive

[Doobrey]

Do you need all the buttons? depends if the game needs them or not..

Anyway, if you've got a multimeter and a CD32 controller  you should be able to figure out what button produces what combination of the 3 inputs.

eg. Button1 only activates the button1 input
but Button4 could activate both 1 and 2, Button 5 activates 1 and 3 etc.

Then adding the extra buttons should only take a couple of diodes for each extra switch.

[adolescent]

The CD32 controller uses a couple of 74LSxxx chips to handle the extra buttons.  The circuit doesn't look overly complicated so you should be able to source the chips and use the original board as a wiring diagram.

To answer your original question, you definately need all the buttons to play CD32 games.  A really important one is "Start".

[amyren]

A search on google revealed an ad on computercity:
Competition Pro CD32 Joypad, supports all 6 buttons. Extra buttons also work on A1200 and A4000. With auto-fire functions.
look at www.computercity.biz

Apearently there are 6 buttons, and the same pad will also work on other amigas, so there is no HW difference in the CD32 joystick port for the extra buttons.

But it seems like the easiest solution is to buy a joypad..

[Doobrey]

adolescent wrote:
The CD32 controller uses a couple of 74LSxxx chips to handle the extra buttons.  The circuit doesn't look overly complicated so you should be able to source the chips and use the original board as a wiring diagram.

Aha.. don't suppose they'd be a 74ls148 8 to 3 encoder and a 74ls04 hex inverter ? (|or possibly a 74ls00 quad nand instead of the inverter)

[adolescent]

@Doobrey

No, I haven't looked in a while, but I found an old post that says they are 74LS125 and 74LS165.  But, I don't feel like opening up any of my working CD32 controls.  :-)