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jamma

Jamma Project Part 2: Vertical Control Panel

For the vertical jamma cab, I decided that I wanted a single player setup. Since vertical shooters are my favourite, I wanted to be centered in front of the screen, and let the player choose whether to play left or right handed. It didn’t really matter which cab I used for vertical and which for horizontal, but I already had a single player control panel that came with one of the Electrocoin Midis, so I made a start getting that how I wanted it…

original vertical control panel


“Wait, that looks pretty darned good!” I hear you say. Yeah it does, the previous owner did a good job but there are a few issues. Firstly, below the red and blue buttons, on either side, there is a small bump where the welded on brackets on the underside have pushed up a little bit. It’s hardly noticeable, but you *can* feel it and it’s annoying enough for me to want to fix. Secondly, the repro overlay had creased under the coach bolts…

original control panel overlay issues

I could forgive that, as again, you don’t really notice it. But after receiving a new overlay from Olly at Arcade Art Shop to use on the other cab (currently with the wooden panel), it looked and felt so much better so I ordered another one so both cabs would be identical. Olly’s overlays are thicker and more hard-wearing than this one, and have a lovely texture to them.

The last change I wanted to make for my vertical panel was the joystick. The current red one had a very long throw and a weak spring. With the square gate it felt very loose and I didn’t like it at all. For shooters you want something with a short throw. Over the years I’ve found these Australian MCA joysticks to be the best. They use a rubber grommet for centering, have a short throw and a small ball-top handle. They’re ruggedly made and feel fantastic. So I would need to swap out the existing joystick for one of these…

australia mca joystick


Before I made a start on the panel itself, I had a bit of tweaking to do to the cabinet with the wooden control panel….

existing control panel in vertical cab


Taking it off you can see below that it sits directly onto the edge of the front panel, and the small mounting blocks with the latches on….

control panel mount wrong


In contrast, this is the cab where the thinner metal control panel sits. You can see that the mounting block is higher up to compensate for the thinner control panel…

how the control panel mount should be


I’d need to move the blocks up so they match the other cab in order to sit a metal panel on it. Luckily they weren’t glued on, and when unscrewed, I could see the original screw holes used before the panel was replaced with a wooden one…

control panel mount taken off


So it was just a simple case of screwing the blocks back on in the original holes. Everything lined up perfectly…

control panel mount fixed


Time to gut the panel then! The existing overlay came off quite easily and didn’t require a heat gun or scraper….

peeling the old overlay off


Soon the panel was back to bare metal and ready for some sanding to get it nice and smooth for the new overlay…

control panel stripped


On the back, these two welded on brackets caused small bumps on the front of the panel, underneath the red and blue buttons…

welded brackets


I used my orbital sander with some 40 grit for a minute or so to flatten the bumps out. Worked a treat, can’t feel them any more…


Time to put the new overlay on. I hate this part. I wanted the blue stripe across the middle of the joystick/button holes, so to line it up I dimmed the lights and shone my phone torch through from underneath. This way I could see exactly where the holes were. I clamped the overlay on each side, then lifted the overlay at the top, peeled back 2 inches or so of the adhesive backing, and cut it off with scissors. Then I carefully laid the overlay down onto the top edge of the panel, smoothing it out with a soft rag to ensure no air bubbles. Then I removed the clamps, peeled off the remaining backing and laid the rest of the overlay down. Looks good!

new overlay installed


I folded the overlay over the back and stuck it down to keep the top and bottom edges nice…

new overlay foldered over


After cutting the holes with a stanley knife, it was ready for the controls. You can really see the nice sheen and texture of this new overlay compared to the older one…

holes cut and nice texture


This is where I realised I’d made a mistake. I’d just presumed that the base of nice MCA joystick would fit snugly in the hole in the panel. I don’t know why I thought this, but it didn’t. The hole was too small! I had no other choice but to enlarge the hole… but now I was paranoid that by doing that I’d wreck the nice new overlay that I’d just put on. Well, sod it, if that happens it happens and I’d need to order another overlay and re-do it. Chalk it down to experience. The hole was 26mm diameter, and I needed it to be 30mm. I got my drill out and prepared my step drill bit to enlarge it…

time for step drill bit


I decided my best bet was probably to go through the top of the panel and cover the edges of the hole with some electrical tape to try to prevent the overlay from getting damaged (I had considered using a metal punch, but every punch I found didn’t go up to the 2mm thickness of this panel)…

ready for step drill bit


I went very slowly and with hardly any pressure, letting the drill do the work. I had to replace the electrical tape a few times, but eventually I got the hole to the right size and the artwork amazingly stayed intact! 🙂 I actually got to 30mm diameter but then accidentally went slightly further with the step drill bit which has ended up giving the hole a nice bevel where the joystick base will sit…

success - enlarged joystick hole


Nice. Well happy with that. The ball-top also fit through the hole meaning I didn’t have to take the joystick apart (these MCA’s are horrid to take apart, they have one small circlip that’s a complete ass-hat to get off without damaging or bending it)…

new joystick installed


Next all the buttons went back in. Looking good…

all buttons installed


Then I wired it back up…

wired back up


All done. And it fits snug on both cabs now I’d modified the mounting brackets….

installed on vertical cab
installed on vertical cab face on


Well that’s the vertical single player control panel done! Very happy how it turned out despite some scary moments along the way. See you in the next part real soon.

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jamma

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.