Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!sjsca4!poffen
From: poffen@sj.ate.slb.com (Russ Poffenberger)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Adding a Third Floppy Drivea
Message-ID: <1991Jan10.003430.20621@sj.ate.slb.com>
Date: 10 Jan 91 00:34:30 GMT
References: <1991Jan8.002139.9708@aplcen.apl.jhu.edu> <68yq028t04=X01@JUTS.ccc.amdahl.com> <932@VAX1.CC.UAKRON.EDU>
Reply-To: poffen@sj.ate.slb.com (Russ Poffenberger)
Distribution: na
Organization: Schlumberger Technologies, San Jose, CA.
Lines: 44

In article <932@VAX1.CC.UAKRON.EDU> r3hjl@VAX1.CC.UAKRON.EDU (Howard J. Lymor) writes:
>In article <68yq028t04=X01@JUTS.ccc.amdahl.com> kls30@DUTS.ccc.amdahl.com (PUT YOUR NAME HERE) writes:
>>In article <1991Jan8.002139.9708@aplcen.apl.jhu.edu> simpson@aplcen (Simpson David) writes:
>>
>>Hard disks are automatically labled after the floppies present.  So if
>>you have 3 floppies (like me) you hard disks will start as D:
>>>
>>>Thanks for any help.
>>>                                 David Simpson
>>/*   Kent L. Shephard  : email - kls30@DUTS.ccc.amdahl.com   */
>
>I'm not so sure about that.  It's been our experience that
>the hard disk drive designator is done by the Fdisk (or some
>other suitable partioning, initializing program).  After that,
>ANY drive, floppy, hard, CD that is added, is given the next
>available letter by the (help me out here for you rom and bios
>folks) bios(?, maybe DOS, but I doubt it).  Anyway, that has
>been our experience with older pc's, xt's and 2 AT's.  
>

No, fdisk does not place any letter designation on the drive. It just makes
the correct FAT entries.

The onboard BIOS will find the first two drives (if connected). Some (but not
all, this causes a problem) will also find the second two. As drives are
encountered, they are placed in a drive table, incrementing the letter. Hard
disks are also put in the drive table.

If your onboard BIOS doesn't recognize the second floppy disks, it won't make
it in the drive table. If it doesn't, at least on my system, I can't even use
DRIVER.SYS, it just can't find the drive.

What you need in this case is a controller card with BIOS on board that
installs the drive into the BIOS drive table.

When DOS boots, it looks through the drive table and assigns letters
appropriately. This means that floppies would be A:, B:, C: and hard disks
would start at D:. (three floppies). If four floppies are present then the
hard disk starts at E:.

Russ Poffenberger               DOMAIN: poffen@sj.ate.slb.com
Schlumberger Technologies       UUCP:   {uunet,decwrl,amdahl}!sjsca4!poffen
1601 Technology Drive		CIS:	72401,276
San Jose, Ca. 95110             (408)437-5254