Grrr - !%#*^@# Kaypro!

[Dave Dunfield]

>>> ???!  The value for R must be a valid sector number.  For floppies
>>> that is never zero.
>>There are a lot of floppies with sector numbers starting with 0.
>>765 can read them and write them.
>
>Maybe... there are caveats on that.  Technically a sector number of 0
>should not be used.
>
>Did a lot of work at "NEC"  (US arm then was NEC Micromputers USA, then later 
>NEC Electronics USA.) in the early years when they were developing and 
>marketing that and a HDC.  I was on the hardware/technical side.

When I designed the 765 based disk system in my D6809/CUBIX system, I "didn't
know better" and numbered the sectors within a track from zero - this would
have been early to mid 80's.

Never changed it, as it has never caused a problem - versions of this system
were built with both NEC and Intel (8272) controllers, and used for many years.

ImageDisk reads and recreates CUBIX disks with no problems.

I cannot find any information in the NEC data sheet which describes any
restriction on the sector number (other than that it is one byte) - can you
provide a reference to these caveats? this is the first I've heard of them.

Regards,
Dave
-- 
dave04a (at)    Dave Dunfield
dunfield (dot)  Firmware development services & tools: www.dunfield.com
com             Collector of vintage computing equipment:
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