TRS-80 Model I info (RE: MSX, TRS-80, Colour Genie, etc.)

From: Allison J Parent <allisonp_at_world.std.com>
Date: Thu Jun 26 09:22:04 1997

> > modifications), and power supply brick. Level I BASIC is similar to
> > Tiny BASIC. I still have my Level I BASIC reference manual.
>
> Level I BASIC _was_ Tiny BASIC.

NO IT WAS NOT. LEVEL-I basic was the same basic sold by gates for the
altair just a later revision level. IT was little, it ws limited but to did
have floating point math and a few otehr things not found in tiny basics of
the time.

Tiny BASIC was one of several basics that
were integer math only and far more limited and generally smaller too.

Once upon a time there were three basics from MS, 4k, 8k, 12k extended,
disk (~23k), and compiled(bascom). L1 was 4k and LII was the 12k extended
with mods.

> Dennis Kitsz did once publish an upgrade to 48k that could be done in a
> keyboard without the EI. I have no idea how many others built it, but I
> never had a problem with the alleged memory speed problems from the EI
> cable. Jerry Pournelle's gripes are another story.

It was never memory speed it was ras/mux/cas timing that was marginal.
after about late 79 the design was substantually changed to derive the
signals loacally in the EI.

stacking 32k more in the keyboard was a trivial task. IF you didn't mind
staking the chips three high and skywiring the cas/ lines for the added
chips to a decoder. It did work well.

> > - RS-232 interface board > For expansion interface.
>
> Worked better than an Apple serial card from the era.

The RS card worked excellent if the connector did!

> I _still_ don't understand that trade-off between cost and utility. The
> decision makers were gone before I joined the company in '80.

INthe trs 80 case some of it was the lack of decision making by other than
marketing/sales types. I was there from 74-79 and helped launch and fix the
trs80


>
> It was more reliable than the cassette interfaces for the Apple or the Pe
> ot the Atari. _All_ cassette interfaces are unreliable. How many people

Generally speaking all audio cassette interfaces were poor. Some were
poorer than others. I'd tried digital (saturation recording) using a
modified trs80(all the analog gone) and it was absolutely reliable. The
recorder electronics were no more complicated than athe audio just
different.


> more than a few eval and review units when Tandy announced the TRS-80
> Microcomputer System on 3 Aug 77 with 5,000 units already in the
> warehouses -- idea was, since they didn't know if it would work, they had
> 5,000 stores -- if the silly things didn't move they'd figure out a way

The first year of sales exceeded 250,000!

> The one Percom used came out after the design was final.

The percom design existed at least a year before the design was started.
It was straight out of the wd1771 data sheet!
Received on Thu Jun 26 1997 - 09:22:04 BST