"CP/M compatible" vs. "MS-DOS Compatible" machines?

[Chuck Guzis]

> Date: Sat, 02 Feb 2008 19:11:16 -0500
> From: "Roy J. Tellason" <rtellason at verizon.net>

> > I asked Gary Kildall, "Now that most commercial machines are going to
> > 5.25 inch disks, what is the STANDARD format for 5.25?" He answered, "8
> > inch single sided single density."
> 
> Can you do that on a 5.25" disk?  What is that,  77 tracks,  I forget how
> many sectors...

26 128-byte sectors per cylinder, single-sided, 77 tracks.  
Interleaved 13:1, directory starts on the third cylinder.

Corresponds more-or-less to a "1.2MB" DSHD 5.25" (or "1.25MB DSHD 
3.5"), but they came along rather late in the evolution of the 5.25" 
drive, which is probably why you see so few of them with formats for 
CP/M-80 systems.  Did the 5.25" DSHD format originate in Japan?

Cheers,
Chuck