14 Jun
2010
14 Jun
'10
2:12 p.m.
On 14 Jun 2010 at 13:56, Eric Smith wrote:
On 06/13/2010 02:53 PM, Chuck Guzis wrote:
Durango 800 (aka the F-85). With the 1781 and GCR, you got 940KB (12
sectors of 512 bytes per track) on a 100 tpi DS2D floppy. The 1781
was pretty buggy, showing a tendency to hang now and then, so a bit
in a latch was used to toggle the MR/ pin. I still have 2 of these
systems.
--Chuck
I've got a 1978 floppy controller here that
uses about 55 ICs, one
of them being a WD1781. A fair amount of the board is taken up by
the data separator--it was designed by a guy whose last job was
designing read channels for the ISS 3330 clone.
What system is it for? I've heard of the 1781, but never seen one.
It was designed to be useful with encodings other than FM and MFM,
such as M2FM.