17 Mar
2002
17 Mar
'02
6:44 a.m.
On Sun, 17 Mar 2002, Joe wrote:
Actually, it is NOT the sme compatility, (nor the
same compatability :-)
problems. The big problem with 360K in 1.2M is the head width. THAT is
OK for "QD". But there can be some problems sometimes with trying to do
"QD" with 1.2M, since sometimes it can be difficult to get it to switch
density without also switching into "double-stepping" mode.
[Note: I'm not really trying to ridicule you about the spelling - at the
last Computer Faire and one year at Comdex, our sign maker
ignored the supplied disk file and delivered our signs saying:
"End disk format incompatility!"]
So, this
means I can make disks from image with a vanilla 5.25 1.2M
drive, on a Linux box, right?
That MIGHT work but I don't recommend it. The
1.2M drive has
compatibility problesm with the 360k drives and it has the sme compatility
problems with the QD drive. You need a drive that's designed for QD and
you need QD disks if at all possible. QD disk have the same coercivity
(SP?) as 360k disks and 1.2M disks use a different coercivity.
Correct spelling.
360K (AND "QD") is 300 Oerstedts; 1.2M is 600
Oerstedts.
Assuming I have DSDD floppies and use the
Pretty EXTREME assumption! Not much besides
CP/M,MP/M understands CP/M
file system and DIRectory structure.
correct device (/dev/fd0D720) with dd?
Alternatively, is there any reason I couldn't temporarily move the
drive itself to a PC to build the disks?
That should work as long as the PC
understands the file structure. You may need to use 22disk or something similar that
understands the Altos
structure.
or Media Master, or Uniform, or "certain others"
That "file structure" IS CP/M. MP/M is a variant in terms of OS
operations, with the same file system structures as CP/M. 'Course there
are a few thousand different CP/M disk formats.
--
Fred Cisin cisin(a)xenosoft.com
XenoSoft http://www.xenosoft.com
PO Box 1236 (510) 558-9366
Berkeley, CA 94701-1236