Re: Disk II Phase Question

[Eric Smith <eric-no-spam-for-me@brouhaha.com>]

"Bryan Parkoff" <nospam@nospam.com> writes:
>     I understand now.  The reason is that I say ($5F00) 24,320 bytes or 
> 194,560 bits per track.

The number of nybbles per track varies because normal nybbles are
8 bits each, while self-sync nybbles are either 9 or 10 bits (determined
by whether the FF pattern is written to the shift register every 36 or 40
microseconds, instead of 32 microseconds for a normal nybble).

There are nominally 50,000 bit positions on a track, which means that
normally there would never be more than 6250 nybbles per track.  Given
the variation in drive speeds, you might see up to 5% higher in practice.