EIDE, aka Ultra ATA (doesn't matter what number - 100, 133) is what you are looking for.

So Why Could I use this hard drive.

Product Description - Hitachi DeskStar 7K80 - hard drive - 80 GB - ATA-100

Type - Hard drive - internal Form Factor - 3.5" x 1/3H Dimensions (WxDxH) - 4 in x 5.7 in x 1 in Weight - 1.3 lbs Capacity - 80 GB Interface Type - ATA-100 Connector - 40 pin IDC Data Transfer Rate - 100 MBps Average Seek Time - 8.8 ms Spindle Speed - 7200 rpm Buffer Size - 2 MB  
Technical Specs Device Type - Hard drive - internal Width - 4 in Depth - 5.7 in Height - 1 in Weight - 1.3 lbs Compatibility - PC Form Factor - 3.5" x 1/3H Capacity - 80 GB Interface Type - ATA-100 Connector - 40 pin IDC Buffer Size - 2 MB Features - Temperature sensor, load/unload technology Drive Transfer Rate - 100 MBps (external) / 94.6 MBps (internal) Seek Time - 8.8 ms (average) Spindle Speed - 7200 rpm Non-Recoverable Errors - 1 per 10^14 Start / Stop Cycles - 50,000 Interfaces - 1 x ATA-100 - 40 pin IDC Compatible Bays - 1 x internal - 3.5" x 1/3H Min Operating Temperature - 41 °F Max Operating Temperature - 131 °F Humidity Range Operating - 8 - 80% Shock Tolerance - 55 g @ 2ms half-sine pulse (operating) / 350 g @ 2ms half-sine pulse (non-operating) Vibration Tolerance - 0.67 g @ RMS (random) (operating) / 1.04 g @ RMS (random) (non-operating) Sound Emission - 26 dB

DeBraNe read my topic.

I have a U-ATA 200 gb harddrive working fine, I just think the Dem 4400 has a Ultra ATA controller that's limited to 140 gb. 200 gb wouldn't work (I tried everything if you read my thread.) So I'll probably have to purchase a new controller if I want 200 gb. Currently settled with 127 gb of the drive, I'll get the full space when I upgrade the computer.

But you should be fine with 80 gb.