Xerox 820-II diskette formats

[Steven Hirsch]

On Sun, 3 May 2009, Chuck Guzis wrote:

> The 820-II 8" samples in my library show 77*1*26*256 and 77*2*26*256
> formats.

That's fairly conservative, but works out to almost a 1MB for the DSDD 
diskettes.  Most systems I'm familiar with formatted at 32 x 256 in DD 
mode.

> I believe that alternative ROMS were also offered by third parties.

I've found a couple of examples out there.

> I believe that there might be source code for the BIOS ROM for the
> 820-II wandering around also.  There certainly is for the Ferguson
> Big Board, which is a close relative.

Would be interested in the "official" sources if anyone can point me to 
them.

Steve


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