xcinders: ATA 100. I assume that means I can't go with a SATA drive.
correct. SATA data and power connectors are different.
xcinders: Would ATA 6 be compatible?
yes. I believe that this is in the FAQ.
xcinders: ...Spindle speed 4200 rpm ( I assume these should not matter for compatibility).
true, but note that faster spinning drives usually, (though not always if your drive is quite old,) requires more power and will thus drain your battery faster.
Tallon41
"I'd like to be buried Indian-style, where they put you up on a high rack, above the ground. That way, you could get hit by meteorites and not even feel it. "
------------------Jack Handy