From: "Matthias Paul" Organization: Rechenzentrum RWTH Aachen To: opendos AT delorie DOT com Date: Tue, 21 Dec 1999 10:53:57 +0100 Subject: Re: X-mailer: Pegasus Mail v3.22 Message-ID: <6A645B7068B@reze-1.rz.rwth-aachen.de> Reply-To: opendos AT delorie DOT com 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 ------------------------------------------------------------------- Matthias Paul, Ubierstrasse 28, D-50321 Bruehl, Germany eMail: Web : http://www.rhrz.uni-bonn.de/~uzs180/mpdokeng.html -------------------------------------------------------------------