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.
The fact that there was a 1773 available for them to use was sufficient
justifiation for switching circuits, though. The 1793+1691+2143 worked fine,
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_at_p850ug1.demon.co.uk>
To: <classiccmp_at_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
>
>
Received on Sat Oct 06 2001 - 23:01:13 BST