I have here a working pull from an eMachines computer. It's an Intel motherboard with an eMachines BIOS.
I'm almost positive it's this board:
http://www.intel.com/design/motherbd/vg/index.htm
Onboard it's equipped with four SATA ports, two PCI slots, 1 PCI Express x1 slot, four DDR slots, onboard 10/100 LAN, onboard GMA900 video, and the LGA775 socket. The only identifying number I see on it is "E210882". The formfactor is an mATX.
You will also need either a 24 pin power supply or an adapter to convert a 20 pin into a 24., which can be found on Newegg for a couple bucks.
Edit - I will include the 300w ATX-sized power supply that I got with the system
Another quirk that I discovered is that you will need a CPU cooler that screws into the board, not one that clips. I found that out while trying to use the now-junked heatsink I got with the board on the MSI that replaced it.
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Also included in the bundle is two 256MB DDR400 CAS3 sticks of RAM, made by Samsung using Samsung chips,
plus the 300w power supply.
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Asking price for the whole thing is $75 + shipping. Heatware under "ArcticFoxCS", bumps appreciated, etc.