386 UNIX and FDISK

[John Plocher]

+-- In article <595 at micropen> dave at micropen (David F. Carlson) writes:
|  +-- In article <280 at uport.UUCP>, plocher at uport.UUCP (John Plocher) writes:
|  |  +--  someone else said:
|  |  | > the basic PC disk IO interrupt 13 only has 10 bits for track number.
|  |  | But the underlying WD1010 register spec allows for 16 bits.
|  |  +--
|  |  But the WD-1002 controller only uses 10 bits, the WD-1003 uses 12.  
|  +--
| Of course, the WD1002 is a floppy only controller.  For the time being
| addressing 1024 cylinders (8.5 meg) on a floppy seems sufficient!  :-)
+--

Sorry, the WD 1002 is a combined hard disk / floppy disk controller that IBM
and most clones sold until the WD 1003 came out.

The 1002 has lots of discrete logic on board to implement both floppy and hard
disk support for the AT.  The 1003 is the same thing done with custom chip sets.

I know because I have several of each here in front of me, and my home system
(hobbes) has a 1002 in it.  I can't say how WD did it, but that "Floppy Only"
controller sure handles that 80Mb CDC Wren fine!  :-)

I know I sometimes stick my foot in my mouth (ok, both of them...), but this
once I know what I'm talking about. :-)))

   -John Plocher