Let's start this project off as though I was going to build a MAME cabinet, OK? I don't want a MAME cabinet and I don't play arcade games, but I'll explain that later.
After a short search, I got my hands on an old cocktail arcade cabinet courtesy of long-time friends of Free Geek Vancouver, The Hackery. (They're just up the street from Free Geek; if you haven't been in, check them out sometime.) Here's how it looked:
This is Space Zap, circa 1980 or so, from Midway. If you're curious about this game, there's a pretty thorough video on Youtube featuring a working example.
I often feel bad tearing apart old equipment. This game was not in great condition, but it was still complete, and someone with more knowledge about arcade games probably could've lavished a lot of love and attention upon it and gotten it working again. If I spend more time than strictly necessary in doting over this old hulk, it's because I'm assuaging some guilty sentiments.
I have never worked on an arcade game, so just getting inside allowed me to answer some long-standing questions. How secure is that little lock on the side panel? How do you service the game? How do you even turn it off and on?
Once the pictured side panel was removed, and its mate on the other side, it's possible to remove the glass sheet from the top. Beneath that the game really starts to show its age:
Pictured is a warped cardboard surround that hides the edges of the chassis, and glued to that is my first surprise -- a colour overlay:
Here's the trick: the game is actually black and white, but by overlaying a coloured sheet over the screen, you'd never know it. Back in the late '70s and early '80s colour equipment was a lot more expensive and complicated and in games like this without much variety in what you see on the screen a real colour setup would've been wasted. (Rumour has it that this game is technically capable of colour output, but was shipped with a B&W screen.)
Beneath the colour overlay is the B&W vacuum tube...
...and there's really nothing else accessible from the top. Over to the side and the aforementioned little door:
This one, fortunately, was unlocked so I didn't need to destroy anything to get inside.
That's the coin slot, a coin counter, the lock mechanism, and a little light bulb, all with that chunky late-1970s feel. I love hardware from this era.
Another mystery answered, after some prodding: how to open the chassis? If you reach inside this little door you can release a couple of catches near the top. (Nothing inside this game was shielded and one catch wasn't too far from the high-voltage flyback transformer. Those were different times.)
With the catches flipped, the top of the case swings open and latches in place for servicing:
The CRT and its power supply and logic board stay with the top; the rest stays below. Here's a look deeper inside.
On the left is the power supply board, with enormous filter capacitors and some voltage regulator chips. If I had to put money on what part of the game failed, I'd say it's probably these.
In the bottom of the case is the board set, which looks like this:
For this game, there are 5 circuit boards: game logic, a pattern board, a CPU board, and two RAM boards.
The CPU and RAM boards would run a number of Midway games from the same era and only the game logic and pattern boards were game-specific. (The are lots of charming manuals kicking around the Internet for this stuff.)
The CPU itself is a Z80 chip, probably most famous for powering the TRS-80, Osborne 1, Timex Sinclair, and other (in)famous computers to pioneer home computing in the late 1970s and early 1980s. It was cheap and it was everywhere.
After a quick look at the manual linked above I'd guess the RAM boards are something like 8KB apiece. Nowadays, of course, we comfortably measure RAM in gigabytes -- a unit (roughly) a million times as big. RAM was expensive and software developers had to pull all kinds of tricks to make things work with the limited resources available. (Running software without enough RAM is like trying to pick something up that you're standing on.)
The game board looks like this:
So I tore out the guts, gave some to John's Jukes (worth a look inside if you ever walk past) and sold some to a guy in Alberta. The rest wasn't especially valuable or in very good shape so overall I can forgive myself for dismembering it. What wasn't used was, of course, responsibly recycled (thanks Free Geek Vancouver and The Hackery).
All right, down to business. First I picked up a motherboard, CPU, RAM, and power supply from Free Geek Vancouver. I got the motherboard cheap because its onboard network card -- and, it turns out, one of the two PCI slots -- are dead. Not a problem; I don't need expandability and there's always USB besides. I built the motherboard into the bottom of the chassis and mounted the power supply to the side.
Looking down from above:
I tested this with an LCD panel to make sure it was working before moving on.
The most challenging part was the CRT. The old screen was around 20", at a slightly unusual aspect ratio. I found that with minimal modification I could get a 19" CRT to fit -- the vertical size is almost perfect, and with some drilling, the same mounts could be made to fit.
Unfortunately, this means stripping the plastic casing off the new screen to get it to fit. The plastic casing on most screens is not just cosmetic; it holds everything together.
Without their plastic casing, there are two major considerations: one, the CRT: fragile, dangerous, and heavy. Two, the circuit boards, fragile and dangerous as well but at least not heavy. The problem is that they're interconnected with thousands of wires, some easy to remove and others more difficult.
Pictured above is my first attempt: a Lacie-branded Mitsubishi display, with the back cover removed.
Here it is with all its boards stripped, ready to be mounted.
And again, secured to the chassis with a screw in each corner.
Look, I shouldn't have to say anything, but don't do this. A CRT is basically a compact collection of things that will try to hurt you: high voltages, high frequencies, possibly X-rays, sharp glass enclosing a vacuum, and sometimes even daytime televison.
Well, long story short: I got all the boards re-installed, powered it up, and it never came back to life. I crammed it all back together and brought it back to Free Geek and told Dave in the warehouse not to ask any questions.
He had another, fortunately: a 10-year-old Dell 19" monitor that had quite literally never been used. It still had the sticker on the front.
Same story: shell it... install it...
This one survived the transplant.
Fortunately, these things are $5 a pop at Free Geek Vancouver -- gone are the days when a big CRT would set you back $800. Nobody wants them anymore. There are still a few hopeful Craigslist vendors trying to squeeze $50 out of some poor sap by quoting the original list price for a 10-year-old behemoth. And I doubt anyone's going to fall for that.
So $5 wasted and the damaged monitor was, of course, ethically recycled. Here's how the Dell looks once installed:
As an added bonus, I have the empty shell to play with.
Next problem: the control panels. First, they were filthy and needed some serious attention.
I stripped them down and scrubbed them off and attached an Ardunio [knock-off] to take care of communications between the switches and the computer.
Wired up with some particularly hideous dead-bugging, here is how it looks:
And the other controller, wired to the same Arduino:
A few other details, too -- I wired the computer's power switch to a little pushbutton hidden beneath the chassis where the old power switch used to be. I also stripped apart a pair of crappy computer speakers and wired the amplifier to the original two speakers in the chassis, and powered the amplifier from the computer's 12V supply so that the amplifier powers on and off with the computer.
So it's time to come clean: I didn't make this into a MAME arcade cabinet. I wrote a small game. With apologies:
The music is courtesy of Mister Beep via the Free Music Archive; some of the images used in the game are from NASA's public domain photo archive.
I still have a couple of things to do: Challenger-themed artwork on the front and side panels, and of course attaching the coin box (though I will of course never run this for profit).
The game is written in C++ using the SDL graphics library. The graphics are intentionally chunky to fit the 1980s esthetic -- SDL is capable of much more. All of this is of course free and open source software.
If anyone is interested I can describe the game software, Arduino interface to the control panels, or anything else.
I'm hoping to exhibit this as part of the East Side Culture Crawl this winter...
(Yes, I know this is awful. The space program is one of humanity's highest achievements and the Challenger explosion was a tragedy. But I made it anyway. It's not the worst game out there -- *that* 1982 piece of excrement is something I won't even link to.)
Edit: I've posted a follow-up addressing some of the fuss over at Hack a Day.