Jamma Project Part 1: The Idea

Years ago, I’m guessing early-to-mid nineties, I bought an Electrocoin Midi arcade cab. I bought it from a local social club when I spotted it in the corner switched off and unused. It caught my eye as it had a Flying Shark marquee – my favourite game! I got the number of the guy who provided cabs to the social club, and he agreed to sell it to me for £110 delivered, including the gameboard! I couldn’t believe my luck. A few years later I sold it, which was a mistake that I’ve regretted ever since.

The Electrocoin Midi cabs are slightly on the small side, but a really good shape with a laid-back monitor angle and nice control panel. They’ve very tidy little cabs that can take a 19″ monitor which you can easily mount horizontally or vertically. Being pretty narrow (about 55cm wide) they’re ideal for small game rooms like mine where you want to fit in as many cabs as you can.

I wanted a couple of cabs in my game room to run a bunch of arcade PCBs that I’d gotten hold of. After discovering the UKVAC forums, it wasn’t long before I managed to secure a couple of Electrocoin Midis. These will be perfect for my game room. I’ll have one running Horizontal orientated games, and the other vertical.

Electrocoin Midi 1

The first one I picked up belonged to a ukvaccer in London. It was in really good condition, and had been done up nicely by the previous owner…

electrocoin midi 1

It had a horizontally orientated monitor with a single player control panel. The overlay was a reproduction of the original Electrocoin design, and wasn’t in bad shape. The joystick wasn’t my cup of tea though, it had a very weak spring and very long throw. No good for shooters…

electrocoin midi 1 control panel

The coin door was in good condition. A free-play button on the left, and a switch-game button on the right, presumably for a Jamma switcher…

electrocoin midi 1 coin door

The cab internals were OK too. As expected there’s the power supply, isolation transformer, Jamma harness and mounting brackets for a Jamma board…

electrocoin midi 1  internals

The monitor was nice and clean. Looks like a Wei-Ya universal chassis (thanks the person on FB that hinted at that), connected to a 19″ burn-free Samsung tube…

electrocoin midi 1 monitor chassis
electrocoin midi 1 monitor neck board

Electrocoin Midi 2

The second Midi I bought wasn’t in quite as good shape. This one would be for vertical games. The marquee retainers had peeling paint and were rusty, and the original metal control panel had been replaced with a plexi-covered wooden one with some horrid starpoint orange buttons…

electrocoin midi 2

The coin door was in bad shape, and not the standard one with the two coin slots. This would have to be replaced to match the other one…

electrocoin midi 2 coin door

The guts were as expected. Power supply, isolation transformer and jamma harness all present…

electrocoin midi 2 internals

The monitor was a 19″ Hantarex MTC 900.E, and it wasn’t working. The tube had lots of screen burn and was a horrid light grey compared to all the other arcade monitors I’ve seen…

electrocoin midi 2 crt

The chassis and neck board were caked in dust, and the neck board had a big split in it. I expect I will be swapping this monitor out for a nicer working one…

electrocoin midi 2 broken neck board

The Plan

Design-wise, I’d like to get both Midis looking like they did in the original Electrocoin Automatics “UNIGAME” flyer below. This primarily means making sure the marquees are replaced, and the control panels and monitor bezel artwork. Luckily both cabs are black, although I may need to re-do the t-molding.

electrocoin unigame flyer
The Midi cabs I have are the same as the MIDI (2nd from right) in this original “UNIGAME” flyer.

I have 10 or so arcade PCBs that I want to play on the 2 cabs. I’ve decided I want them on show on the wall, in a nice display cabinet above each cab. I looked online everywhere for something suitable, but in the end I had to design my own as I couldn’t find anything flexible enough for my needs. First (as usual) I doodled something in Sketchup. The frame would use MakerBeamXL 15mm profiles, the shelves/top will be 2mm thick aluminium sheets, and the front and sides 4mm thick clear plexiglass. The whole unit will be 500mm deep x 500mm tall x 400mm wide. The shelves will be cut short to allow for cablewang at the back, and the sides/front will be held on with magnets so I can remove them to give me easy access to the PCBs should I want to change them at any time. I’ll make 2 of these, mounting them on the walls above the cabs. I’ll make some nice labels to go on the front of each shelf to show what the games inside are…

jamma board display cabinet sketchup plans

I’ve ordered an 8-way Jamma switcher for each cab that I plan to have mounted on the wall directly underneath each PCB cabinet. The game boards will be cycled through via a button on the coin door…

jamma coin insert switcher button

Lastly, I plan to have a PC in each one running GroovyMame, for the various games that I don’t have PCBs for. The PC will be connected to one of the ports on the Jamma switcher via an Ultimarc JPAC, so in effect it will add itself into the cycle of boards in the PCB cabinet.

Well, it’s pretty ambitious, I’ll give you that. But I already have the cabs, they’re not in terrible shape, I already have the PCBs, and I’ve built MAME cabs before so I know what’s involved there. And I’m not afraid of any of it. 🙂 Lets just hope these 8-way switchers work as expected when they arrive!

See you in the next part where I think I’ll make a start on the control panel for the vertical cab.

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