I have yet to see anyone post that a specific model has problems with DataMaster. It's just a standard Windows program, and thus will run on basically any computer than can run Windows.
I'm using a 120MHz, 32MB laptop I was given. Not the greatest, but it works. If it's a relatively new computer, you'll want to check the serial ports. USB will require some other work, so a DB9 serial port is probably the best way to go. Other than that, just as fast and as much memory as you can afford. When was the last time you used a computer and thought "Gee, this is just too fast. I wish I would've saved the $20 and got the slower one."? =)
