TRS-80 models (Was: TRS 80 Model 12 Picked up

Fred Cisin cisin at
Wed Jul 29 13:57:52 CDT 2020

On Wed, 29 Jul 2020, Will Cooke via cctalk wrote:
> There are several TRS-80 sites and groups around.  YOu might check those for parts and support.  Here is one that looks promising.  They appear to have disks available for some models.  If they don't have what you need perhaps they can point you toward some other person or site.

Most here know this well and better than I do; some were involved in the 
creation of it.
But, for SOME, it's confusing.
So, here is an over-simplified review of the TRS-80 model numbers:

We talk about the "TRS-80 family", ONE SIDE OF WHICH is what Ira 
deals with in that link.   THAT does not deal with Model 12, but Ira is a 
great guy who will try to point you to who does.

BUT, it is NOT all one family.
And the numbers are intertwined.
I had a great great grandfather named Frazier.  He used to "party 
across the river" with his "other family". The TWO families of TRS-80 
are about as related as I am to the Lakota Sioux.

The original "TRS-80" was intended as a hobby computer.  It expanded.
It had a memory map that was incomapatible with CP/M.  It had TRS-DOS 2.0, 
written by Randy Cook for a few days, and then TRS-DOS 2.1, 2.2 (never 
quite finished).
2.3 was patched without Randy Cook, had who come up with FANTASTIC ideas, 
but couldn't seem to finish anything.
There were hardware modifications to make the "TRS-80 Model 1" CP/M 
compatible (Parasitic Engineering ShuffleBoard and Omikron Mapper)

machine called the "TRS-80 Model II", that was aimed at BUSINESS (and 
almost missed the target).  It had 8 inch drives, and could run CP/M 
("Pickles And Trout"), and "Model 2 TRS-DOS", which had little in common 
with Model 1 TRS-DOS except the name.

The original TRS-80 was renamed "TRS-80 Model 1", very soon after, making
"TRS-80 Model 1" a newer NAME than "TRS-80 Model 2" (just like "Single 
Density" (FM) is a newer NAME than "Double Density" (MFM), and "World War 
1" was a newer NAME than "World War 2")

Third parties upgraded TRS-DOS, with NewDOS, DOSPlus, VTOS 3.0, etc.
More details are available.
VTOS was by Randy Cook, and NEVER quite finished.
So was VTOS 4.0

Lobo Drives desperately needed a modified form of TRS-DOS for use with 
their third Party Expansion Interface (with double density and 8" drives) 
for Model 1.
So, they bought rights for VTOS, and hired every TRS-80 systems programmer 
that they could find, and finished VTOS into LDOS 5.0

Then there was an upgrade and major repackaging for a new version of the 
Model 1, called "TRS-80 Model 3".
It had double density, so the Model 3 ran "Model 3 TRS-DOS 1.3", which was 
a patched version of TRS-DOS 2.3 (which was NOT double density)

But, NewDOS, DOSPlus, And LDOS also worked on the "Model 3", so few people 
used "Model 3 TRS-DOS".
Radio Shack bought rights to distribute LDOS as TRS-DOS 6.0
Randy Cook then made more royalties than he had for the original TRS-DOS 
that he had written.

Then "minor" hardware upgrades, including having a switchable memory map, 
80x24 screen, a "Control Key", etc. to make a version of the Model 3 that 
could also run CP/M.
That was the "TRS-80 Model 4".  They made a luggable version, called the 
"TRS-80 Model 4P"

Meanwhile,  . . .
Radio Shack introduced a minor upgrade of the "Model II" called "TRS-80 
Model 12".  Smaller, lighter, half-height drives.  (This is where we came 
Q: was the model number based on a confusion between "II" and eleven in 
the "Model II" name? ("12" logically comes after eleven, not roman numeral 
for 2)
And, they developed a coprocessor, and introduced the "Model 16", which 
had Z80 AND 68000, to run CP/M, "Model 2/12 TRS-DOS", and Xenix.
They released a minor upgrade called the "TRS-80 Model 16B".
The model 12 could be upgraded into a model 16B.
THEN, they thought that "Radio Shack" as a name, was the reason for poor 
sales, so they renamed the model 16B, "Tandy 6000".

So, we have the progression of the model 1, 3, 4 and 4P.

UNRELATED, we have the TRS-80 Model 2/II, 12, 16/16B/Tandy 6000.

Two familes related in little except name and some old history.

There were also the "Radio Shack Color Computer" (6809 based), which 
eventually became the "TANDY Color Computer", which is deserving of its 
own separate discussions.

And, the "Model 100" (a Kyocera machine like the NEC and Olivetti), which 
was the last machine that Bill Gates had a significant role in writing software. 
ALSO worthy of its own discussions.

Then they started making PC's, starting with MS-DOS machines that were not 
fully PC compatible.  Some of those are almost "classic".

Grumpy Ol' Fred     		cisin at

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