The List!

From: Roger Merchberger <zmerch_at_mail.northernway.net>
Date: Fri May 2 13:47:03 1997

On Fri, 2 May 1997, Gary S. Katz wrote:

> Well, here's my 2 bits on the ??'s in the Tandy Line...
>
> > 102 80C85 32K Proprietary ROM PORT. 86
>
> There were some rudimentary OS for the 100/102 with the
> serial-port, tough-as-nails, 3.5" floppy drive. Without
> the drive, you used a ROM-based menu system.

I'm very big on the Tandy equipment in question (have 5 machines now...)
and have already sent Bill a listing about several of the machines listed
in this e-mail... but I do want to clear up a few misconceptions here.

The DOS (not OS) in question above only did rudementary communication
with the floppy drive... The floppy had it's own micrprocessor, ram and
DOS built-in, and all you had to do is send it commands. That's one
reason why it's so easy to interface to any other system (like a PeeCee).
You just pipe it commands & data thru the RS-232, it does the rest. It
still relied on the ROM-based menu system to work whether or not the
drive was plugged in.

Even the DVI (Disk-Video Interface, which enabled you to use an 80x25
mono text screen with VT52 (or was it VT-100) emulation and 2 40TkSSDD
drives) still relied on the ROM-based software to function.

> > 6000 68000 512K ?? MICRO 84
>
> I'm fairly certain this machine had it's own flavor of
> TRSDOS but I'm not big on the 2/12/6K line.

The 6000 could run anything for the II/12 on it's Z80 CPU, but the main
OS for this machine was XENIX, which ran on the 68K.

> Not much I can do here. There was a Coco 1 which topped out
> at 32K with the same CPU (I think). There was also a micro-
> version of the COCO, the MC-10, which was perversely half-
> compatible with the COCO line. Had a 6809C CPU (I think),
> upgradable from 4K (stock) to 16K with an add-on plastic
> block that had a tendency to fall out at inopportune times.

No, the CoCo1 went to 64K, just like all the others. The *early* revision
boards needed a small hardware mod (2 wires, I believe) but the later
models (altho advertised at 32K) were in fact completely function 64K
upgrades. Also, the MC-10 with the 16K "dongle" totalled 20K. You are
correct in the statement that it was a very poor arrangement for
upgrading, tho!

> > PC-4 Z80 ?? ?? PORT. 83
> > PC-5 Z80 ?? ?? PORT. 85
> > PC-6 Z80 8K ?? PORT. 86
>
> There are (as you'd no doubt guessed) a Portable Computer,
> a PC-2, and a PC-3. I don't think they carried Z80s, but
> I may be wrong. The PC-3 had a 24-character LCD with a
> max of 4K of RAM.

Trivia: The PC-2 (which I *think* had a 26-chr screen) could do graphics!
I programmed in a craps game that actually showed the dice! Wish I still
had 'er! <sniff>

> > Color Computer 6809 16K ?? MICRO 84
> > Micro Color Computer 6809 64K ?? MICRO 84
>
> Oops... you had these. I think the Coco could go to 32K &
> the MC10 could only go to 16K. I'm fairly certain that the
> CPU on the MC10 was not a true-blue 6809.

See above, but also, the MC-10 was based on the Motorola 6803, and was
*not* ML compatible whatsoever, as the instruction base was more along
the lines of the 6800, not the 09.

> Hope this helps!

Me too!

Cheers,
Roger "Merch" Merchberger
Received on Fri May 02 1997 - 13:47:03 BST