Kaypro II format oddities

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Thu Feb 13 15:56:01 2003

The original question was whether it is possible to write Kaypro diskettes
in a PC. If you have the opportunity to also do the formatting in the PC,
then it is pretty easy with appropriate software.

Single sided Kaypro diskettes are usually not a problem.
But, if you need to work with double sided diskettes that were formatted
by the Kaypro, for either reading OR writing, then there are some minor

The Kaypro uses a Western Digital type of FDC chip, the PC uses an NEC 765
type. The WD chip can ignore certain fields in the sector headers,
specifically including the "Side number" field. When the Kaypro formats a
DS diskette, it puts an INCORRECT value in the side number field of the
sectors on the second side. That doesn't pose a problem for the Kaypro,
since it can just ignore that field when reading or writing its own

But the NEC 765 (in a PC) can not ignore that field. It is possible with
most PC disk controllers to control the FDC directly and have it look for
that wrong value. But only if communicating directly with the chip, NOT
when doing disk I/O through the BIOS.

There was a period of time when a number of machines came out that did not
respond appropriately to attempts to work directly with the FDC, but could
still do fairly versatile disk I/O through the BIOS. To avoid a
disastrous level of needed tech support, XenoCopy operates at a BIOS
level, and even Uniform (from Micro Solutions) DISCONTINUED support of
Kaypro double sided formats.

Fred Cisin                      cisin_at_xenosoft.com
XenoSoft                        http://www.xenosoft.com
On Thu, 13 Feb 2003, Feldman, Robert wrote:
> Because of a peculiarity in the Kaypro format (Fred Cisin has gone over this
> before, but I don't have the details at hand), you must format the Kaypro
> disk on your target PC for it to work. This formatting can be done on a PC
> with programs such as Xenocopy, MediaMaster, Convert. The disk formated on
> the PC can then be used in the Kaypro. You can copy files from native Kaypro
> disks to this disk, then read it in the PC with the software.
> -----Original Message-----
> From: Mike van Bokhoven [mailto:mike_at_ambientdesign.com]
> Sent: Wednesday, February 12, 2003 6:03 AM
> To: cctech_at_classiccmp.org
> Subject: Kaypro II
> <snip>
> - Does anyone know if it's possible to write Kaypro disks with a PC and 5
> 1/4 inch drive? If not - any hints on where to dig up software?
> <snip>
> Mike.
Received on Thu Feb 13 2003 - 15:56:01 GMT

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