On Feb 4, 11:43, Ethan Dicks wrote:
> --- Pete Turnbull <pete_at_dunnington.u-net.com> wrote:
> > The 1772 was designed to be a plug-in replacement. The main (only?)
> > difference is in the programmed step rates.
>
> I am looking at a WDC-1772. It has 28 pins. Doesn't the 1770 have 40
pins?
No, you're thinking of a 1790. 1770 and 1772 are both 28-pin devices.
There's also a 1772-2 which is just a mask revision of the 1772, and a
1772-2-2 which can run faster. Ataris sometimes have the latter.
> The standard 5.25" drives _do_ use GCR for all native formats, but the
later
> stuff (1570/1571) also do MFM for CP/M compatibility. The aforementioned
1581
> is a 3.5" device (~720K; the not-released 1591 was ~1.44Mb) and does have
some
> form of MFM-capable chip, AFAIK. You can read 1581 disks in other
machines,
> Linux included, I think.
I didn't know that. Did Commodore machines use a standard controller to
write the MFM, or did they use the same techniques as for the GCR? I know
Amigas can read/write DOS disks, but they don't have any sort of standard
controller.
--
Pete Peter Turnbull
Dept. of Computer Science
University of York
Received on Fri Feb 04 2000 - 14:34:31 GMT