So what do I have running under the hood of this bad boy? The truth of the matter may shock many of you young people.
450mhz AMD k6-2
128mb PC100 SDRAM
ATI Rage 3D II (Video Card)
Sound Blaster 16 PCI
540Mb Western Digital Hard Disk
Hagstrom LP24 Keyboard Encoder.
You read that correctly! 540 Megabytes! But then again, I'm not even using 1/3 of that capacity. Ahh the glory of DOS.
Originally, I was using Fraggal's Boot CD to take care of the setup of all the software, it automatically installs and sets up your sound card, AdvanceMAME, and ArcadeOS, which is a graphical front end. Well it turns out that AdvanceMAME is a HUGE pain in the ass to set up and have it run correctly, (it has 50 billion config options, because it was designed so you could run MAME on a real arcade monitor or television. Eventually I deleted everything and just used plain MAME version .37b17, which was the last official build to be K6 optimized, and ArcadeOS. Later I switched to a more recent version of DOS mame that was compiled to K6 by a kind soul. You can get that here.
I'd like to mention a little bit about the keyboard controller. I'm using the LP24 from Hagstrom Electronics, I don't know if this is an issue with other keyboard encoders like the I-PAC, but make sure that the control panel and any metal components that the encoder is attached to are electrically grounded, in a wooden cabinet with a metal CP, even small amounts of static electricity can travel down the button wires and confuse the encoder, either making you re-upload the configuration to the device or restart the machine.
Try as I might, it just wasn't feasible to get this junk to run off of an Arcade power supply. Most arcade supplies just aren't powerful enough to run a computer, so I just used a standard PC AT power supply that I had handy. I will mention that AT motherboards are nice as they use a hardware power switch, so it's possible to have one switch power your entire cabinet. You can do this with an ATX machine, but it takes more work. Luckily I was able to run the coin door lights from the PC supply as well.