12 Oct
2008
12 Oct
'08
5:16 a.m.
--- On Sun, 10/12/08, Chuck Guzis <cclist at sydex.com> wrote:
I remember seeing the punchers, but I never had one. I just used a hand drill, and drilled
them one at a time. I also had a couple that I had needed to convert at the computer lab
at school - which I did by cutting that corner off the disk with a paper cutter...
You're right. I am leaving something out. I also changed a jumper on the drive to do
that. And, on one drive, I had to mess with the wiring of the spindle motor. Thanks for
reminding me.
readable).
Didn't even need to drill holes in the
disks to 'upgrade'
them. Of course, these days, I find myself taping
over
the holes in
disks, since DD media is hard to find.
At one time, diskette "punchers" were a popular
item at computer swap
meets. The price differential between HD and DD media at
one point
was substantial. I've made
high density 5 1/4" drives into 80
track double density
(720K) drives by cutting the trace on the board
that
leads to pin 2,
and tying it to ground. This forces the drive
into DD
recording.
You're leaving something out here. While that forces
the drive into
DD recording mode, the spindle speed doesn't change
unless the drive
is also jumpered for "dual-speed" 300/360 mode.
So there can be a
real difference between a "fixed" drive and a
genuine 720K DSQD
drive. Grab some documentation on early 1.44MB drives. You
could
often
configure them for "auto sense" (the way most
recent drives are by
default) or "remote sense" in which the status of
the media sensor is
fed back to the host and the host selects the density via
pin 2. Or
do it the way the PS/2 did and ignore the media type
completely.
Ah. that makes sense. I figured that there had to be some kind of function for that.
-Ian