Date: Tue, 20 Mar 2001 04:28:04 -0600
From: Rob McGee <i812 AT iname DOT com>
To: opendos AT delorie DOT com
Subject: DOS drive letter assignments
Message-ID: <20010320042804.B24471@sl7>
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Forgive me if this is in the archives. I did try searching Google and
the MSKB and came up empty.

Suppose you have 4 IDE hard drives, each with 2 primary DOS partitions
and 2 logical DOS partitions in an extended partition. How are drive
letters assigned? Let's just say these are all partitioned like this, to
borrow Linux naming conventions:
    hdX: hdX1 hdX2 hdX3 < hdX5 hdX6 >
And yes, for sake of argument each partition is of a type recognized by
DOS. No type 82 or 83 or 07 or anything else confusing. :) How about
type 06 all the way around?

Obviously partition 1 on the primary master is C. Is partition 2 D? Then
which is E, number 1 on the secondary master or the primary slave?

What happens when you throw some BIOS-controlled SCSI into the fray? Say
you have 2 SCSI drives on a single bus, partitioned just like the IDE
gang. Are their primary partitions assigned drive letters before the
logical partitions on the IDE drives?

What about a second SCSI bus just like that one? Which SCSI bus is
first? (Yes, I realize that there are not enough drive letters for the
second bus, but I am interested in the order of assignments primarily.
Since all this is hypothetical we can take out the IDE secondary slave
and one of the SCSI drives; then we're still under 24.)

What fun questions. :) Does anyone know the answers? Thanks!

    Rob - /dev/rob0