Yes, it's possible to write a 360k disk in a 1.2MB drive. See
On Wed, Apr 24, 2013 at 3:55 PM, Tothwolf <tothwolf at concentric.net> wrote:
On Tue, 23 Apr 2013, Jim Brain wrote:
Kapyro 1, working drives, boots. Many thanks for Gene and Mike Loewen
for boot disks and app disks.
Kaypro 4. A drive does not work, B marginally works. I got it to boot!
4-84: Neither TM100 works, and A must have a short as no voltage when
connected. With disconnected, and B set up as A, no boot.
10: I *think* the drive works, as the universal Kaypro 1 boot disk
continues to cycle from the 1.93 boot screen to a cursor in the top left
corner, and back.
So, I dug out the PC and attached 2 1.2MB 5.25" floppies and got Dave's
utils over there, along with a K10 CPM 2.2F boot disk img (in td0 format).
Converted to IMD format.
That was the end of my successes.
testfdc sees the drive, but only 300kB DD seems to work. I tried making
an image with the 1.2MB drive, but every sector said write error: no data,
so I gave up.
Then, I took a working Kaypro drive and put it in the PC, and tried
testfdc. I overrode it as 360kb 5.25 drive, and testfdc finds the drive,
but it immediately gives up stating "!No FDC Interrupt"
So, if there is "a way to do it...", it continues to elude me.
While I'm not a Kaypro expert, I seem to remember that the Kaypro uses a
true Shugart interface for the floppy drives, so you aren't going to be
able to connect a Shugart type floppy drive directly to a PC-compatible
floppy interface without moving some signals around on the cable. I ran
into this last year while troubleshooting another type of Shugart interface
floppy drive, which I was originally expecting to be PC-compatible.
Is it even possible to write reliable 360K disk using a 1.2MB drive? It
had been ages since I worked with some of these drives since a lot of my
stuff is packed away, but I seem to remember that I always had to use a
360K drive when /writing/ 360K disks, while I could still read 360K disks
in a 1.2MB drive just fine. (The tracks written by a 1.2MB drive are
narrower than those written by a 360K drive?)