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From: bmarsh@cod.NOSC.MIL (William C. Marsh)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Disk Driver Formatting in DOS 4.01
Keywords: driver formatting dos 4.01
Message-ID: <1623@cod.NOSC.MIL>
Date: 29 Aug 89 23:27:38 GMT
Organization: Naval Ocean Systems Center, San Diego
Lines: 32


>What happens is DOS formats the disk fine, writes the boot sector, and 
>then complains that it couldn't write 'BOOT', track 0 bad, etc.  However,
>the sector is written properly, according to both Norton and a INT-13
>sniffer I wrote.  The driver only uses the BIOS routines for interfacing
>to the disk.


Here is some more data about the formatting process.  After FORMAT is
finished formatting the drive, it does an INT 26 to write the BOOT
sector onto the disk.  This returns OK.  Then, it does a Generic
IOCTL call, with CX = 0846h.  08 means disk access, but 46 is un-
documented as far as I can tell.  I have looked into many DOS books
(including Advanced Dos (including 4.0)), and this sub-function is
not documented.  I have a DOS 4.0 Tech Reference on order...

I have a feeling this call concerns the serial numbers added in
version 4.X, but I can't support what I don't know!

I also changed the Generic IOCTL handler in the driver to always
return OK if it doesn't understand the sub-function, and the drive
formatted OK with no errors...

Help!

Thanks in advance!

Bill Marsh, Naval Ocean Systems Center, San Diego, CA
{arpa,mil}net: bmarsh@cod.nosc.mil
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