Adding Autofire circuit to a joypad

[elbarto]

On the old boards, Matt posted a circuit diagram for adding autofire to a controller. Does anyone have this saved, and if so, can they re-post it?

thanks

[Rastan78]

You should check this link out. That's auto translated into english and this is the original page:

http://galford.hp.infoseek.co.jp/sync.html

Galford is the world record holder with Tavia on Gunbird 2, so I take it this is the type of circuit players in Japan are using. On this IC you can get different firing rates by connecting different pins. GAL even gives the ideal firing rates to be used on several well-known games.

Thanks go to BER for posting the links on the click-stick bbs. P.S. if anyone gets this to work, I'm sure there'd be a lot of us here who'd love to see a newbie type guide on making the circuit. No doubt there's a few here who would only need the schematic, but personally I haven't done anything like this for quite a while.

[shiftace]

Ok, I basically get what this is doing -- MC14022 pin 14 is the clock, and pins 2, 1, 3, 7, 11, 4, 5, and 10 are outputs 0-7 respectively (see datasheet). If you connect A (reset) to one of those outputs, then the counter resets when that output is reached, and pin 2/output 0 goes high. Pin 2 connects to the NAND chip (7400), which is mostly being used as a couple of inverters.

So here are my main questions:
- Why are 7400 pins 11-13 used as an inverter?
- Why do they bother with the carry bit (counter pin 12)?