On Sun 02 Aug 2015 21:35:16 NZST +1200, Peter Simmonds wrote: > Was just selling an old floppy drive on Trademe, and some > interesting technical details coming out of this;
> "It has a bank of jumpers on the back; DS0, DS1, DS2, DS3, MD, MM, > RDY, DC, TTL/CMOS" > It is only an old DD floppy drive out of an old amiga 1200. Is there > anything special about it? I doubt it. DSx will be device select, for when you have multiple drives on the same cable. 4 is higher than I remember, it might be a bit souped up over time - as is probably the TTL/CMOS compatibility switch. RDY I think was used to power down the drive when not in use; the jumper disables that if the host doesn't control it. MD/MM, DC I'm not sure. Search the Internet for "shugart bus", that was the company that invented the bus and it was often referred to as that. I am sure I have old drive manuals lieing around, but I don't remember any super special floppy drives having existed. The Olde Apple ][ had an anomaly in the drives. Its magnetic stream recording format was hand-doctored and used a much larger gap between flux direction changes. Normal, standard floppy drives couldn't handle that because their read amplifier lower frequency limit was too high. The trick was to solder 150pF onto 2 test pins, which, somehow, never failed to exist somewhere on the circuit board. They were easy to find too, touching 150pF to arbitrary pins was always non-destructive. It changed the read amplifier bandwidth. Post that Apple I believe all floppy drives were standard, off-the-shelf industry stuff. Volker -- Volker Kuhlmann http://volker.top.geek.nz/ Please do not CC list postings to me. _______________________________________________ Linux-users mailing list [email protected] http://lists.canterbury.ac.nz/mailman/listinfo/linux-users
