Mail Archives: opendos/1999/12/21/14:11:43
On Mon, 20 Dec 1999 Pavel V. Ozerski wrote:
> Seller created 7 logical FAT16 drives which were avalaible from MS-
> DOS part of Win'95. But I tried to restore my favourite
> configuration: Windows NT 4 as main system and DR-DOS 7.03 as 'first
> aid system'. Now NT works successfully and can use all existing
> logical drives but DR-DOS knows only about drive C: How to make
> another partitions (even if several) to be visible from DR-DOS?
Hm, if these subsequent partitions are logical drives in an extended
partition, and are (still) formatted with FAT16, DR-DOS should see
them. If it doesn t, I have the suspicion that either NT has
transformed them into NTFS partitions, or that NT has removed
EZ-DRIVE from the MBR (because MS setup programs usually don t care
much of other OSes installed, or because NT does not need EZ-DRIVE
to access the full disk). If this is the case, you would need to
reinstall EZ-DRIVE (or at least refresh the MBR code). I am not used
to EZ-DRIVE, but a similar product (Ontrack DiskManager) provides
such a facility.
Depending on how you switch between the two OSes, there might be
another cause for the problem. You can use NT s FlexBoot Loader
and/or DR-DOS LOADER to switch between them. Since the DR-DOS
LOADER resides in the MBR, installing LOADER might have removed
the EZ-DRIVE MBR. In this case, you should remove LOADER again
(this should reinstall the old MBR, that is the EZ-DRIVE MBR, if
it wasn t changed by NT setup). Once you have the EZ-DRIVE MBR code
refreshed, you should boot from hard disk, but break the boot process
when the EZ-DRIVE MBR code displays its startup message (at least
Ontrack s DiskManager has such a startup banner) before any OS or
boot loader will be loaded. There should be an option to continue
booting of a floppy disk. Once you have booted DR-DOS from floppy
this way, you should reinstall the DR-DOS LOADER again. But remember,
just the usual floppy boot right from the start won t do, as the EZ-
DRIVE MBR code won t be loaded this way.
But since the EZ-DRIVE MBR was from harddisk loaded before the
floppy boot, you already have LBA and >8GB support at this stage.
Any hard disk access should then go through the EZ-DRIVE code in
memory. This means that accessing the MBR and boot sector (and
any other sector) will not necessarily access the same physical
sector, but a translated "virtual" sector as emulated by EZ-DRIVE.
Hence, the DR-DOS LOADER will not actually install into the
physical MBR (and thereby remove EZ-DRIVE again), but will into
the "virtual" MBR as seen under EZ-DRIVE. This would allow peaceful
coexistance and thereby easy switching between NT and DR-DOS (with
EZ-DRIVE still active).
Please tell us, if this could help you any further.
Matthias
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Matthias Paul, Ubierstrasse 28, D-50321 Bruehl, Germany
eMail: <Matthias DOT Paul AT post DOT rwth-aachen DOT de>
Web : http://www.rhrz.uni-bonn.de/~uzs180/mpdokeng.html
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