Programming for Alternate Controllers

[Richard James]

I don't think the DB9 is correctly mapped to the VIA's input pins for a Sega Genesis pad. Also the VIA can only do all output or all input on a 8bit port so you can't set line 7 to high,low and read the values because as soon as you change the DDR from output to input it probably will lose the line 7 signal.

[ral-clan]

I'm still not sure it is a good idea to connect a Genesis gamepad and push just about any button. Perhaps as long as there is something in the way to draw power, one won't cause short circuit with the 5V line. But you're a brave man!

I'm not sure how much of this applies to the VIC, but in another discussion (about DIY USB controllers) Golan provided a link to an off-forum thread, which provided a link to this bit of information:

http://www.floodgap.com/retrobits/ckb/display.cgi?26

It's about the potential SEGA controllers have for blowing CIAs in C64s.

[carlsson]

Are you talking about actually building a new input device?

I've been toying with this idea again, mostly because I have a huge bag of tactile switches and a small batch of proto boards. I don't know what kind of controller I would like to make - something with multiple switches for sure, but perhaps also a stick of some kind.

Actually for a split second I thought the DC3 involved some new controller, but perhaps it would be an idea for a DC4. We still have the Denial Community Collection to put together, whether that should be a separate entry or part of the Denial Collection series. Ha! Notice I called it a serie now when Jeff has made three different ones.

I realize this thread for the moment being may fit better in Hardware than Programming, but perhaps the first stop should be Design, if a such forum section had existed. Before a piece of hardware is created, I have a feeling it is a good thing to decide what it should do.

Possible types of controllers would be buzzers for quiz type games, logic and pattern following games. One joystick port could support two controllers with three buttons each, plus an additional utility button. Initially I thought five input lines could support more controllers but I forgot the fact several people may want to make a move at the same time...

Of course with some added electronics on the controller and the application reading pulses instead of checking each input line on/off, the complexity can be increased. This is where the hardware guys could come in, suggestions what can be done to make it even more advanced. I realize the KoalaPad and others must use some pulse encoding.

[Jeff-20]

Actually for a split second I thought the DC3 involved some new controller, but perhaps it would be an idea for a DC4.

I lack the resources and technical knowledge to attempt that.

But why not explore using controllers many of us already have?

- The Atari Keypad (identical to the Kid's Controller and the Video Touch Pad) could be fun to use.

- The Atari Driving Controller is similar to the paddles, but a game could make use of the 360 degree rotation.

- The XE Lightgun, in theory, should work on a VIC too.

-The 7800 joystick or pad would add an extra button.

How many of you have access to the above controllers? I don't want to assume they are plentiful; I don't have any kind of VIC-compatible light pen or light gun device. I do have the others, but it wouldn't make much sense to make a program for them if the controllers are too rare to find.

[carlsson]

I have neither. But the point was how many of those are compatible and safe to use on the VIC-20. We don't want to plug in something that suddenly will zap our VIC's to death just because we accidentally tried to move in an illegal direction. If a new custom controller is designed, it can be made to be guaranteed VIC compatible, no worries about tying 5V directly to ground and so on.