Xerox 820-II diskette formats

[js at cimmeri.com]

Steven Hirsch wrote:
>>> 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.
>> What?!   Using what controller chip?  How that's even possible while 
>> maintaining the same 360rpm?
>
> Too early in the day...  Just checked the sources for the formatter, 
> and it's 30 256-byte sectors per track not 32.

So clarify this for me.   Someone figured that they could squeeze more 
out of a track than the IBM System 34 standard?  How was this done?  By 
decreasing decreasing the gap lengths?

 jS