TRS80 Model 3 i/o connectors

From: Glen Goodwin <acme_ent_at_bellsouth.net>
Date: Fri Nov 1 12:14:00 2002

> From: Tony Duell <ard_at_p850ug1.demon.co.uk>

> True, but you'd be amazed at what some people have problems with :-)

Well, even at my advanced age I can still spot a mains connector ;>)
 
> > Thanks for the information. I'll be poking around this critter more
this
> > weekend. Any gotchas I should know about?
>
> If you take the case apart, you need to realise that the monitor is not
> separately enclosed inside/ This means that (a) there's high voltages
> around (actually, there are also high voltages on the non-encased SMPSU
> boards in there too...) and (b) the CRT neck is exposed and vulnerable.
> It is possible to catch the end of the neck on the CPU board chassis when

> putting the case together, and crack it. Then you're looking for a new
CRT.
>
> The monitor PCB + CRT are fixed to the top part of the case, everything
> else is on the baseplate.

The service manual was helpful in opening the case. I show a lot of
respect for CRTs when handling them! I had to remove the deadly-looking
bare PSU mounted on the drive enclosure in order to work on the drives, so
it also got the kid-glove treatment . . .

What I meant by gotchas was: anything troublesome about the serial or
parallel i/o? Any known bugs in the ROM? The manual very nicely documents
the ROM routines (if the book is accurate) so this thing should be fun to
do some assembler programming on.

So far, despite all I've heard about "trash 80," this system looks pretty
friendly.

Later --

Glen
0/0
Received on Fri Nov 01 2002 - 12:14:00 GMT