"CP/M compatible" vs. "MS-DOS Compatible" machines? - test-drb@ccmp.vtda.org

3 Feb 2008

...
  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