6502 BASIC or Assembler and Intel 8271/WDC 1770 info req'd

From: Don Maslin <donm_at_cts.com>
Date: Sun Oct 7 00:25:06 2001

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 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 Sun Oct 07 2001 - 00:25:06 BST