VIA C3 MACHINE (Getting dismantled for a different case currently)
This machine started out as one I threw together to get some floppy disks backed up, and ended up realizing it's a bad ass machine for DOS/early Windows stuff. As some other posters have pointed out, the C3 is very adaptable to different speeds and performance levels from anywhere from a 386 to similar to a PII/PIII. The specs are a VIA 800mhz Samuel-2 CPU, 512MB DDR, onboard VIA UniChrome CLE266 graphics, CMI9761A onboard audio, Sony floppy drive, BenQ 56X CD drive, 32GB CompactFlash card on an adapter directly into the primary IDE channel (the motherboard knows and complains about no cable even though it works!) in a Rosewill micro ATX case with a EVGA 500W power supply. I was running this off the 8GB Quantum Fireball hard drive on there until I cloned it to the CF card and added Linux. I use Goteks on my Pentium II machines.
The motherboard this is based around is a PC Chips M789CG 3.0, which came with either a CPU socket or in BGA form soldered directly to the motherboard. I ended up going with one of those, as the only C3 CPU offered in soldered-down format is the 800mhz which is the fastest of the Samuel 2's. I noticed the CPU power draw goes down exponentially as the clock rate goes down. It seems to pull about 13w at 800mhz. It runs a little warm, even though it's about 15C under its advised limit, so I will try to take off the heat sink one day that i'm bored if it starts getting warmer on average, and put some fresh thermal grease on there. It looks like the heatsink is held down by 2 annoying looking plastic screws with springs. I forgot to take a picture of the back when I had out for recapping. This board was a pain as it had very narrow but deep PCB holes for the caps.
This particular motherboard I got for pocket change since, even though it was booting up, the IDE devices weren't detected. All four of the main power capacitors on the board were shot and leaking electro goop. I'd assume the board was run for a long time before I got it. They were only rated to 6.3V and had 5V going through them, at the hottest point of the motherboard too. it probably would have been better for PC Chips to put 10v's there given the temperature concerns. Either way, I put some fancy 10k hour 105c caps there so it should be good to go for a long time. The 10k hour ones cost a lot more than the 1k-2k hour ones but it's worth it for peace of mind. I wish the 5v was a little closer to 5v but it's fairly stable so probably not worth complaining about.
The inside of the PC is pretty messy. That's how it goes when you have a lot of devices connected with ribbon cables anyway. Frustratingly, this board WILL let you boot from USB, but it's USB 1.0 rates and the drive won't even boot without PLOP most of the time. I was able to get the XP and FreeDOS installers to boot but then it couldn't find the install files. So, I ended up burning a lot of CDs.
One of the things I like about the BIOS is it has a lot of color themes to pick from. It also has some interesting features like USB and even USB thumb drive support for DOS.
I was a little disappointed that with the CD, CF and Floppy drives hooked up, it pulls almost 50 watts off the wall. My AL440LX machine with a PII-300 pulls similar numbers. BUT, in XP with VIA chipset drivers installed and power management enabled in the BIOS, and no CD drive, I could get down to about 25 watts off the wall on average.
The CLE266 graphics aren't bad performing overall, but as you can imagine it's not great besides 2D usages. It does not perform great in 3D but 2D/DOS support is great from what I've tried so far. The board doesn't have AGP, so you're stuck with PCI graphics on this board. But, the onboard graphics are more than good enough for DOS gaming. It also has ideal 9x support. I have a 4GB CF card with 98SE on it. The 32GB card in there right now has the latest FreeDOS, Windows XP, and Ubuntu 8.04. It was ridiculously difficult finding a Linux distro with a kernel that has cmov and VIA C3 support. I was just about to give up and compile Gentoo on my main machine for it, when I found a post on Google of someone else who had the same issue who was able to run Ubuntu 8. It's not ideal by a long shot but it works, and I will try to find a more modern browser for it sometime soon...
SimTower performance can't even be compared to my Pentium II machines, it runs as good as a PIII at the least.