Using a 1.44MB 3.5inch floppy on an old controller

From: Louis Schulman <louiss_at_gate.net>
Date: Sun Apr 22 12:52:44 2001

It's simpler than that. The drive recognizes the media as HD or DD by
the hole (or lack of hole). So the drive uses DD, which is acceptable
to the controller, when you use DD media. If you put in HD media, and
taped over the hole, it would work as well.

Louis

On Sun, 22 Apr 2001 11:42:15 -0500, Michael Brutman wrote:

#I have a few PCjrs running around, and I've often thought of
#either adding 3.5" drives to them, or replacing the standard
#5.25" drive with 3.5" drives. The controller only supports
#double density data rates (250?), so I'm limited to 720KB
#3.5" drives. These are getting hard to find.
#
#I connected a new 1.44MB drive to the controller, and
#behold, it worked! (With double density media of course.)
#The machine booted from the diskette (which was created from
#a 360kb image prepared on a Linux machine), and it also ran
#diagnostics. So now I'm confused - why did it work?
#
#Does the modern 1.44MB drive sense that the controller is
#only sending data at 250KHz rate? If so, how is it doing
#the sensing? (The reduced write-current pin (2) isn't
#being used - I verified that with a meter.)
#
#Thanks,
#Mike
#
Received on Sun Apr 22 2001 - 12:52:44 BST