Disassembly, fixing of some small bits, examination of internals
February 2003

I received my shipment from Ultimarc, as you can see. Clockwise from the top-left we have a couple of cables (PS/2 link and USB-serial), the video amplifier and arcade monitor cable, the I-PAC (which converts joystick and button commands to keyboard presses so the computer can understand them), the Opti-PAC (like the I-PAC but for optical devices like trackballs and spinners), and finally the ArcadeVGA monitor card with driver CD. It needs Windows 98/ME or XP to run so I think I'll go with 98. Also, in order to run 2 trackballs I'll have to install MAME Analog+ and Win98 so that's settled.

Now, the video amplifier is important in order to boost the video signal from the graphics card to something of the level that a normal arcade monitor can handle. There are some brands of monitor that can take the low voltage out of a PC but if you don't know what yours is like, buy the amplifier. I haven't heard of any monitor not handling this boosted voltage level (but I won't buy you a new one if it blows up! Check to make sure.)
An email from Bob Roberts on the 19th tells me he has my money and is shipping my gear. ETA is 4-7 days.
I spent some time looking for a small keyboard to keep in my cabinet. I thought I might go for wireless but there aren't too many choices, especially in a small form-factor like this. However, after a few hours I remembered that I had gutted on old portable PC in the mid-90s or so that had a removable keyboard. A quick search in the shed and voila! Gave it a quick test and it seems fine, except that the function key to access the numeric pad sends out a TAB keypress (but otherwise works correctly.) Weird, but it saves me some decent bucks. I've also ordered a PS/2 extension cable as the one connected to the keyboard is pretty shrimpy. This little baby will be hung from hooks inside the cabinet if I ever need it. I've got heaps of wasted space inside the cabinet that I can't really use and this will fill some of it nicely.
I've been looking at car audio to use as a sound system. I was originally going to use a PC setup with 2 speakers and a sub-woofer but had a change of mind. I'm thinking now I'll use some car audio gear and give it a bit of kick. That way I can also use the machine as an MP3 jukebox for parties or something. Here you can see the fruits of my labours in designing a box to enclose the 10-inch sub-woofer in. You can't beat cardboard for decent mock-ups, and things like this are invaluable to get a proper feel for what you need.
Here you can see another shot of the mock-up showing the angle of the rear face. It has to match that of the rear wall of the cabinet and I've yet to really nail down what the angle is. I have no specific tool to do it with, so armed with my high school trigonometry skills and a tape measure I managed to devise a number of methods of working it out. They gave me answers of either 74, 75 or 76 degrees so I'm going with the average. Hopefully this will be close enough over the small size involved. If it's out a bit I can probably use some foam to pad the wall of the enclosure or something. We'll see.
Here is the base of the cabinet removed for a closer look. It is made out of plywood and has seen a few kicks so I decided to build a replacement. There are heaps of screws in it to try and firm it up a bit but it's just too nasty to keep. Now, I'm pretty light-on for both woodworking skill and tools, so even something as basic as this is going to be a bit of an adventure. The old base is some really dodgy plywood. The new one will be a soft timber like pine or something - it only has to take the weight along the short edge of the timber so it shouldn't really matter.
Here you can see what I like to call the "poor man's workshop." My garage complete with wheelie-bins, pushbike, and spare washing machine. In the foreground you can see my saw-horse which saw previous life as a microwave oven (as featured HERE, if you feel like a laugh.)
The old base is on the right and my new one is partly constructed on the left. I've decided to re-use the plywood triangle pieces to save me some tricky sawing. Unfortunately I didn't plan things too well. Although I knew my timber was thicker than the old stuff by about 3 or 4mm, I failed to adjust the lengths of the sides to take this into account. This means my frame is bigger, and the holes in the triangle pieces don't line up with the bolt holes on the cabinet. What a twat! It's not like I'm unaware of the old adage "measure twice, cut once", it's just that I forgot all about it.

I put the frame on the cabinet and it still fits okay (phew!) but I have to redrill some holes and remove the old t-nuts. Hopefully the holes aren't too close together to make the fitting weak but I won't be sure until I put the base on properly.
Here is the underside of the cabinet with the new holes drilled. My base comes no further higher (towards the back) than the old base, so it comes further forward. However, there is plenty of overhang on the front so you won't really be able to tell. Plus the length difference is only about 10mm at the most. While the cabinet is upside-down and I'm painting the finished base frame (which is on the right sitting on top of the old one) I decide to paint over some scratches in the back of the cabinet. Works well and saves me from re-laminating the whole thing. I also got some polyfiller out and filled in the holes left from taking the padlock stuff off the cabinet. I'm going to paint over them with blue paint sooner or later but that's pretty low on the list. I can't see any reason to replace the whole side and front door just for a few little holes.
Now in the little collage to the left you can see the coin mechanism and some other hardware. The inset in the top left is the credit controller (or something - I don't know what the proper technical term is.) I've put in a translucent white shape that hopefully shows you where this PCB fits in relation to everything else. It lies parallel with the power supply (the thing with "110v" written on it) in a socket like the little green one you can see beside it.
Anyway, the coin mech (a Mars ME111 if you're interested) I can work out - it takes various voltages and spits out others depending on what coins are put through. The controller, on the other hand, is a complete mystery. It is supposed to tell the video game when a credit is supplied. So, you put in $1 and it says "Hey! Put a credit up for this guy!" You put in $2 and it sends 3 credits (or 2, depending on how stingy your arcade is. Do they still give more credits when you put in larger denominations or is this a thing from my childhood?) However, you need to put in quite a few 20c pieces to get 1 credit (well, 5 anyway.)

It will be impossible to attach this to my PC to handle credits correctly, according to MARK SCOTFORD - I'm a bit disappointed. The best I can do is get a credit up whenever a coin I allow through the mech is put in. Good enough but not perfect. Another option is to buy a credit controller from the UK for about 40 Pounds (!) and write my own software. Not likely. Ah well, I guess you have to lose some authenticity when you build a MAME cabinet.

NOTE: I am NOT an electrician. Don't think that I know what I'm talking about when it comes to electricity. I like to think I know what I'm doing but I'm NOT qualified in any way. Reproduce my work AT YOUR OWN RISK.