TRS-80 Model 1 (was: Arty computers (was: Re: PDP-11/70 in Yates Center, KS)

Jim Isbell, W5JAI jim.isbell at
Thu Feb 1 15:04:18 CST 2007

Yes, the Pet and the Apple along with the TRS-80 were the first.  Each had
an advantage and a place.  Without any one of them the PC might not be today
what it is.

The TRS-80 seemed to have the biggest following of "Hackers" (hackers were
something else back in those days.  It meant someone who hacked a printed
circuit board to add a trace or remove one) who were always finding ways to
speed up the CPU, add interfaces, add functions, or improve in some way on
the circuit that Tandy provided.  Many of these "hacks" were added by Tandy
in their following models.

My point was that while the TRS-80 might not be "interesting" today.  It was
very interesting in its day because it worked and was modifiable.  As to the
failure rate,  Just about all, if not all, of the reliability problems were
fixable with a #2 pencil with an eraser.  All that was required was to pull
apart any connection made by an edge card and "erase" the grunge off of it.
It has always amazed me that even though the contacts were gold plated they
still required cleaning with an eraser about every two months.

I doubt there are many people today who would try "hacking" a PC
motherboard.  Takes too much knowledge in order to keep from really screwing
up something in the process and three level boards are really hard to hack.

My TRS-80 had every hack published at the time.  My Commodore 2001 had
dozens of hacks.  And there were third party providers that sold "kits" for
various hacks and PC Board additions.  Yes, those were "interesting" times.

On 2/1/07, Ethan Dicks <ethan.dicks at> wrote:
> On 2/1/07, Jim Isbell, W5JAI <jim.isbell at> wrote:
> > The apple was a flop, yes.  The Commodore also was a flop.  Just look at
> the
> > numbers.  The apple was a flop because it was marketed as entertainment
> and
> > drawing pictures (which it excelled at) while the TRS-80 was a
> scientific
> > machine that crunched numbers.
> Hmm... my recollection of the times was that the TRS-80 was pitched
> more as a home/business computer, not scientific.
> Certainly until the CP/M card for the Apple II came out, it was
> primarily an entertainment computer, but at a place I worked at in
> 1984, the boss used his Apple more in CP/M than AppleDOS - for
> spreadsheets, especially.
> >  Yes, today the tables are reversed, but back
> > then, those of us who were into computers (I had been in computers since
> > 1960 on the IBM 7070) were looking for computing power for serious work.
> > The Apple was just not that.  The Commodore didnt make it because it was
> > under powered and again was marketed toward using it for games not
> serious
> > work.
> While the 4K/8K original PET with the 40 col screen and chicklet keys
> had a ways to go until it could be taken seriously outside of the
> home/entertainment market, it had one thing that no other mass market
> computer had at the time - an IEEE-488 (GPIB) bus.  I have seen plenty
> of PETs used in laboratory settings to talk to DVMs, pH meters,
> oscilloscopes, etc., all with the built-in IEEE port.  It might not
> have been a great machine for number crunching, but for a wee while,
> it was a great machine for data collection.  The all-in-one
> construction was also a benefit in the classroom as well as the
> laboratory - sturdy, easy to move, trivial to install ("plug into
> wall, flip switch").  Without dragging this into a 40col vs 64 col vs
> 80col or 1MHz 6502 vs 4MHz Z80 debate, the PET had its place in
> history.
> -ethan

Jim Isbell
"If you are not living on the edge, well then,
you are just taking up too much space."

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