Floppy Minor Device Numbers on V/AT 2.4

[Wolf N. Paul]

I have just installed a 1.44M 3.5" floppy drive in my V/AT system,
and discovered that the documentation on minor device numbers is
rather sketchy.

The following table has been gleaned from the manual (fl.7), as
well as from the 2.4 Release Notes (p. R-4), and the /dev/rdsk directory
on the 2.4 boot floppy.

If anyone can fill in the missing pieces, please let me know.

Format      Drive 0 Name    Minor       Drive 0 Name    Minor     Notes
-----------------------------------------------------------------------
360K        fd048ds9          23        fd148ds9          91        1
720K        fd096ds9          87        fd196ds9         ????       2
720K        fd0mf2dd         119        fd1mf2dd         ????       2
1.2M        fd096ds15         70        fd196ds15         78
1.2M (-t0)  0s25             198        1s25             ????       3
1.44M       fd0mf2hd         102        fd1mf2hd         ????
1.44M (-t0) ?????????       ?????       ???????????      ????       3

Notes:

1. Is there a way to access 320K diskettes, which I believe is the
   default format of the UNIX PC?

2. What is the difference between the fd096ds9 and fd0mf2dd 720K formats?
   (as far as the device driver is concerned, I know that the actual disks
   differ in size and media material, but the format seems the same, 80
   tracks of 9 sectors each).

3. How does one read "Installit" format diskettes on drive 1, and is there
   an "Installit" format for 1.44M diskettes? (As I understand it, 
   "Installit" format disks start on track 1 instead of 0).

4. Is there any rational relationship between the minor numbers for drive
   0 and the minor numbers for drive 1, so one can calculate the missing
   node numbers?


-- 
Wolf N. Paul * 3387 Sam Rayburn Run * Carrollton TX 75007 * (214) 306-9101
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