2 May
2006
2 May
'06
12:33 p.m.
On 5/2/2006 at 1:44 PM Roy J. Tellason wrote:
I think it's perhaps got something to do with that
"disk change" line,
which was not implemented on a lot of the earlier 360K drives. If they
didn't
use it they may have it grounded or something. I also
seem to remember
some
adapters that were to convert card edge to pins (or the
other way around)
that had a jumper for this, and could maybe even dig one up here if you
want...
Pin 34 was often used as a "Ready" line on earlier 360K (well, 48 tpi
5.25"
drives), but it was gated off of drive select, so it shouldn't matter. A
bit of cello tape over the edge connector pin should confirm that. I'd
wonder more about the vintage of the 5.25" drive, some of which used 150
ohm pullups on input lines. This may require a bit too much drive current
from a modern CMOS floppy interface. When I got a
Catweasel I, I found
that it had problems with some old 5.25' drives. I simply
wired up a
buffer with some 74LS07s and LS14s, which cleared the problem up.
Cheers,
Chuck