6 Oct
2001
6 Oct
'01
2:10 a.m.
If you use the WD37C65, (available, yet today, via Rochester Electronics) though
you do have to use two crystals to cover the range of needed clocks, it is
designed to drive the cable directly.
Dick
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <classiccmp(a)classiccmp.org>
Sent: Friday, October 05, 2001 6:25 PM
Subject: Re: 6502 BASIC or Assembler and Intel 8271/WDC 1770 info req'd
BTW, I also
need some info on the Intel 8271 disk controller - I've got two
I would not do a new design using the 8271. The chip is fairly hard to
find now, and there are machines that _need_ them (like the old Acorn
Systems).
In fact, I'd probably use one of the all-in-one PC floppy controller
chips unless there was a very good reason not to. Add a crystal and
perhaps some cable driver chips. That's all...
of these little devils and Intel's datasheet
makes absolutely no sense at
all. I've also got a Western Digital WD1770-PH 00-02 that I might be able to
use instead. First of all, which is the better controller? The 8271 or the
1770? Also, is it possible to overclock a 1770 or an 8271 like you can a
1772?
Oh, use the 1770. It does double density (MFM) for one thing (the 8271 is
single-density only). It also require many fewer support circuits I
think.
The 1770 and 1772 are closely related (the difference being the step
rates the chips can produce). I would guess that the 1770 can be
overclocked, but I've never tried it.
-tony