Grrr - !%#*^@# Kaypro!

Dwight K. Elvey dwight.elvey at
Wed Aug 3 18:26:20 CDT 2005

>From: "Fred Cisin" <cisin at>
>On Wed, 3 Aug 2005, Allison wrote:
>> Dave, your on track.  The CHRN vlaues do not have to corrospond
>> to actual head or cylinder.  They do not even have to be in order
>> on the media!   The only limits on them are R must be 1 or greater
>> (less than 255).
>Which creates some complications with handling 128 byte sectors (R==0).
>> My favorite format was sectors 1- 9 (512 DD) on side one and
>> side two was 10-19 with H always set to 0.
>Easily handled by 765, but not by Int13h.
>I have to be careful to differentiate which complications are
>due to the FDC chip, which to the FDC board/implementation,
>and which are BIOS linitations.
>Nitpick: don't you mean 0 - 9 on first side?  Or did it actually have 9
>sectors on one side and 10 sectors on the other?
>I've seen disks with 10h and 20h in the H field.
>My favorite was 1 in the H field for the first side and 0 in the H
>field on the second side.
>And, of course, there are some formats, such as Superbrain,
>where the data (sector content) is inverted,
>but the headers (CHRN) are not.

 How about the sector number being bit reversed but
the data not ( my Nicolet 1080 ). Actually it is
a record numbers, not sector but used in place of
sector headers. When I was trying to figure out how
to format the disk, this cause me a lot of grief.
The only record I could get to work was 0.


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