There are several differences between the Smith Cornoa PWP 2000 and the PWP 4000. They both come with a disk drive so that you can save your work--but the 2000 has a screen, and the 4000 doesn't. It does, however, come with a serial port on the back--so it can technically be hooked up to a computer (don't ask me for drivers--I don't have them).
The PWP 4000 is also a little larger--it's more substantial than the 2000, and will fit as the centerpiece of a desk, instead of becoming a side show like most typewriters.
