Joystick/Keyboard matrix decoding

Talk about programming CreatiVision (except games programming). Projects of homebrew hardware are also welcome.
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nippur72
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Joystick/Keyboard matrix decoding

Post by nippur72 » Wed Mar 16, 2022 11:15 am

Is there a schematic diagram for the joystick/keyboard matrix? By looking at the datasheet (circuit 3.pdf) I see the PIA data ports are connected to J1 and J2, which I think are the joysticks connectors, but I have no clue how they are actually wired.

My actual understanding of the decoding is (please correct me if I am wrong):
- PA3, PA2, PA1, PA0 work as "select" lines (negated logic, activated when "0")
- the user queries the matrix in 4 steps, one for each select line
- at each step, the port B of the PIA is read and parsed into joystick directions or keystrokes (negated logic here as well, "0" means key pressed)

The Salora/2001 seems to have totally a different matrix, with PA2,3,4,5,6,7 as select lines for keyboard and second joystick, and PA0,1 for first joystick.

Is the above correct?
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Scouter3d
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Re: Joystick/Keyboard matrix decoding

Post by Scouter3d » Wed Mar 16, 2022 1:25 pm

Hi,

here is an excel sheet with the creativision Key and Joystick mappings (as seen from PIN numbers of J1 and J2)
for most keys two lines must be connected to the Select-lines at once...
hope this helps...

And yes, Salora / Laser 2001 have a very different matrix / setup...

Cheers, TOM:0)
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