There were 7.5 computers in the TRS-80 line: Models I, II,
III, 4, 100, 102, 200. The Model 4P was a portable version of
the Model 4 with no tape drive -- only 2 1/2-height single
sided disk drives.
Later models that Radio Shack produced were not TRS-80
machines -- they were based on the Intel 80x8x architecture.
These included Tandy 1000, Tandy 2000, Tandy 3000, and others.
The 1000 had a proprietary Color card. The 2000 was a
powerful machine for its time, but was based on the Intel
80186, so when IBM didn't build a computer based on this
chip, it failed. It was used to design a boat for the
The TRS-80 GUI, DeskMate, was proprietary, but no more than
Windoze at the time.
Many joke about "TRaSh-80" machines but several models were
in fact classics of their time.