Re: [stella] Reading Paddles?

Subject: Re: [stella] Reading Paddles?
From: Glenn Saunders <cybpunks2@xxxxxxxxxxxxx>
Date: Sat, 11 Jan 2003 09:36:39 -0800
At 01:25 AM 1/11/2003 -0500, you wrote:
It depends.  There is some overlap between the 2 controller types.  But I
forget the details.  I think maybe joystick left and right are the 2 paddle
buttons.  Anyone know for sure?  There's nothing to prevent you from reading
the controllers at the same time....just the overlap of the functions.

We've talked about this once before during the Death Derby days.

Both controller ports together feed 8 bits of digital data to a single hardware register, plus the four pot lines elsewhere. Custom controllers could be created to use any combination of these signals and games can read all of them in the kernel if necessary. There is no technical reason why you can't.

The driving controller has two unused signals which could be tapped, enabling more complex games for that controller.

Similarly, I think the main limitation in using the paddles is only having one fire button. Being able to use a joystick or track n field controller in parallel with the paddle would enable more complicated gameplay using the paddles. There are pins leftover for one additional button per paddle, plus one leftover to fight over (the joystick trigger).

And the pot lines can be used to simulate digital on/offs as done by the CBS Booster grip to allow for more buttons for joysticks. The method used to read the booster grip is nowhere near as processor-intensive as regular paddle reads because it just needs enough precision to determine an on/off state.

I also think one could rig an analog joystick to the 2600 by using both pot lines (I would like to see this for Marble Craze). But of course, most games don't use the paddles because of the constraints it puts on the kernel.

I think using a custom controller is a good way to increase the chances that people will use a real machine to play your homebrew, although certainly emulation authors could make their controller code more flexible to support these sorts of games over time...

Speaking of which, is there ANY solution out there that people know of that hacks a gravis dual-shock type gamepad or something which outputs to a DB9 female that is signal-compatible with the vcs (including pot lines)?

The only thing I've seen involves making permanent changes to your joysticks.

I already have a home-made Y-cable hack that lets me use a joystick with the driving controller but I can't try this out on Stella or Atari800Win.

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