TRS-80 Model III

From: Sellam Ismail <>
Date: Wed Aug 7 23:30:01 2002

On Thu, 8 Aug 2002, Tony Duell wrote:

> > Nope, still no video. The video is hosed. Along with the rest of the
> > units I've tried.
> Are you sure it's not the BREAK key? I have had bad keyboard contacts on
> M3 keyboards...

No, I'm not. Good point. I think I'll work the key or clean it as Fred
suggests and see where that leads.

> Also, it is possible to set the external controls so that the video is
> invisible (absolutely no video signal at all). After holding down break
> and pressing reset, fiddle with the video controls.

I have the brightness set very high so I can see any text that may pop up
on the screen, but I still think the horizontal hold needs adjustment
before I'll see anything legible.

> > On the other hand, I've rarely met an Apple ][ that didn't boot.
> > Coincidence? You be the judge.
> Odd.... I've never had a TRS-80 that's failed to boot (other than needing
> cleaning of external connectors). I've had plenty of Apple ][ problems.
> Perhaps it's just that I know the TRS-80 better, I have all the service
> manuals to hand, so if i have even minor problems I know what to look for
> and how to prevent said problems becoming major ones.

That's probably true. I was just in a very ornery mood when I wrote that
after unsuccessfully trying to get a TRS-80 Model III, a Commodore 64, and
an Atari 800 working without success.

> Well, I have the M3 service manual alongside me, but since the fault you
> describe could be caused by hundreds of things, you've not given me much
> to go on. Do you have a multimeter? A logic probe? A 'scope?

Yes, no, yes, but I'll try the simple suggestions first before we have to
go that route.


Sellam Ismail Vintage Computer Festival
International Man of Intrigue and Danger

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Received on Wed Aug 07 2002 - 23:30:01 BST

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