TRS80, other than model 1

[Fred Cisin]

On Sat, 13 Jun 2015, tony duell wrote:
> Trivia question : What feature was present on all disk based M1s (in 
> fact any M1 with an expansion
> interface) but not on any M3 or M4 machines?

composite video out.  I used that, a LOT for classroom lectures, etc.
1771 FDC
dual cassette port?
or unreliability of model 1 power supply?
or flaky interface between "cpu" and EI?
model 1 expansion bus
"ability to ignore" some model 3 I/O ports?

There are a lot of differences.  MOSTLY minor (mostly harmless?)
as to which ones are "features", . . .