So....I've been looking at Multi-Jamma devices for ages now, and I have run into the age-old conundrum with them, which is that they don't support kick harnesses, and certainly not all of the mame inputs.
I'm not an electrical engineer, and I'm only minimally competent at electronics. Someone over at Shoryuken turned me on to the Arduino boards (
http://arduino.cc), and the neat thing about them is that interface up nicely using USB or serial, and they're not difficult to program.
So here's what I'm thinking:
Take a piece of breadboard, and if such a beast exists, find an 80 pin interface header (I was thinking EIDE at first, but that's 50 pins, with an 80 conductor wire, isn't it?), and at my last count, JAMMA has 48 pins that are really needed to switch inputs (4 redundant grounds at the bottom and the keys are excluded). Then we have the imaginary player 3 and player 4 inputs, and for the sake of sanity, we'll presume each has a joystick (4), and 6 shots, start, and coin - so 12 x 2, so additional 24. That gives us 72, and if I actually found an 80 pin interface header, this would be perfect. So step 1 would be to take the 80 conductor ribbon cable, and wire it into your cabinet just as you would your jamma harness - your jamma harness will be one of many inputs later on.
On the breadboard, all 80 inputs will need to have traces. I don't look forward to this part, but let's pretend this is easy.
Elsewhere on the board, these 80 traces are going to be tied into a bank of bus switches, like this one:
http://www.fairchildsemi.com/ds/FS/FSTD32211.pdfThat one only supports 48 lines, so I'm not sure if they 80 line or greater version or not, I'm hoping they do. The way the bus switch works in simple - that particular model has two full banks of switches, and by grounding a single pin, all of the pins in that bank are switched on. So we simply tie those two pins together, and ground our new line, and now that bank of pins is going to our cabinet.
So you would have a bus switch for every game in your cabinet, tie it into the switch bus using a bus switch (heh), and then you only have to ground a single line to get your game on. You could use a single pole mulit-position switch, or in my case I'm thinking of putting each of my bus switch "trigger" lines into a digital port on an arduino, allowing me to do further automation.
On the opposite side of each of the bus switches, you would wire either a jamma loom, or a computer, or a console, or whatever. It would be up to you.
If anyone else here has a bit more experience with this sort of stuff, please chime in. It looks to me like arduino = $20-ish (optional), 80-pin interface header (who knows...), I'm having a hard time sourcing that particular bus switch, but I'd like to think $10 for each of those - so if I allowed 4 inputs, $40. The only other thing would be of course getting a board laid out and etched for it.
Am I insane?
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Topic: Plotting a better "Multi-Jamma" (Read 2786 times)
