7 Oct
2001
7 Oct
'01
5:08 a.m.
I was not a RS user at the time and it's quite possible that the rumors I heard
regarding the M1 and those about the M3 were geting mixed together. I wasn't
even aware that there wasn't a two-sided option on the stock model 3.
There were several third-party gimmicks that did a number of things in one wham,
though. There was one "fix" for the data separator that also provided a switch
in the memory map that enabled one to run CP/M, all the while increasing the CPU
speed, and another that incorportated the serial port and a hard disk interface
into the main box, albeit with external drives (weren't those the stock thing?)
and an external bridge controller to a HDC, apparenlty intended to coreside with
the drives. The original pacakging concept for the model 1 was a complete bust,
with loose hardware all over the place, and one could see the RS was determined
to reign in that problem. Unfortunately, they still liked selling packaging far
too much.
I had a client here in Denver, part of whose business was selling an alternative
OS for the TRS-80, called NewDos-80. It apparently sold quite well. I was
unable to convince them, at the time, (1981) to allow me to whip up a memory map
switch so the user could select a memory map that would support CP/M. I had
already provided them with a PSU design for their after-market disk drive box,
and sold them quite a load of transformers (acquired from MITS, when they went
under), and it seemed reasonable to me to go after their business in a larger
way. Since they, like Radio Shack, were heavily invested in their own OS, they
didn't see any benefit in encouraging their customer base to use CP/M. I didn't
agree, of course.
Dick
----- Original Message -----
From: "Don Maslin" <donm(a)cts.com>
To: <classiccmp(a)classiccmp.org>
Sent: Saturday, October 06, 2001 11:25 PM
Subject: Re: 6502 BASIC or Assembler and Intel 8271/WDC 1770 info req'd
fine,
On Sat, 6 Oct 2001, Richard Erlacher wrote:
> Apparently, though I have no specific knowledge of it, the RS FDC left
something
> to be desired, as there were several aftermarket
products that plugged in to
the
> main board to take its place. Since the stock
board used the "official"
Western
> Digital circuitry, I can't think of one good
reason why they should have had
> trouble with the thing, but if there hadn't been problems, there wouldn't
have
been the
third-party market either.
Probably to provide the DS capability that the factory issue lacked.
- don
> The fact that there was a 1773 available for them to use was sufficient
> justifiation for switching circuits, though. The 1793+1691+2143 worked > but required alignment before it could be
shipped, while the all-digital
1773
> required no alignment procedure, and wouldn't
get out of adjustment over
time.
This saved
quite a bit of labor.
Dick
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Saturday, October 06, 2001 5:17 PM
Subject: Re: 6502 BASIC or Assembler and Intel 8271/WDC 1770 info req'd
The later
(gate array) TRS-80 Model 4 systems used a 1773 FDC, which was
Interesting. The older model 4s (like mine) have a 1793 -- the floppy
controller board is indentical to that in a model 3. I'd assumed they
used that board in the gate array versions as well.
Maybe they did (in the early gate array machines), and then changed to
the 1773 for the last ones. I don't see any reason why that couldn't have
been done -- as you said the 1773 and 1793 are pretty much compatible.
-tony