14 Mar
2006
14 Mar
'06
6:25 a.m.
I don't recall when it changed, but the first several versions of MS-DOS
did require io.sys and msdos.sys to be the first two files on the disk.
I would guess that changed at DOS 4.x or 5.x so that IIRC only io.sys
had to be the first file on the disk.
Being lazy, I would most likely go to machine running the version of DOS
you want to install, and make a system floppy and add any other files
you want/need. Then use "attrib -h -s -r" to make everything visable,
and just copy them (in the same order as on the boot floppy) to the
partition in question from whatever has access to that partition. I'm
assuming here that you have a way of getting files to some other OS on
that computer so they can be transferred to the DOS partition.
ISTR that copying them to a formatted floppy would not work as something
needed to be done to the boot sector, but I don't think that limitation
applied to HDs. To boot from the HD, that partition needed to be made
active using fdisk.
I've never dealt with systems that can boot multiple OSs or the boot
software that can handle that part, so I don't know the tricks of doing
that part.
IIRC, the maximum partition size is a function of the version of DOS you
are using (33 MB or so for 3.3 and earlier.)
I want to put MSDOS on the FAT partition and
triple-boot the machine - but the
laptop has no floppy drive on it, so I can't just boot from a DOS floppy and
run SYS that way.
So is there a way of putting the necessary files on there from either Windows
or Linux such that DOS will boot? Can't remember how MSDOS does it's boot
process now, but I assume that certain files (io.sys for one) need to be in
certain locations on the FAT partition or something?
At one point I would have known how to do this, but the info's long since
fallen out of my brain...
(Currently I'm booting Debian / Win2k from Grub - it should handle booting
MSDOS too though).
Before I shoot myself in the foot, are there any other gotchas (like MSDOS
needing to be the first partition on the drive or anything nuts like that)?
The FAT partition is about 2GB into the disk - I seem to recall that a FAT
partition can't be more than 2GB in size, but presumably providing the BIOS
can see the whole disk DOS won't care about the offset to the start of the
partition?
(All I actually want to do is put Slackware Linux on the machine there in
place of Debian, but the CDROM drive's too flakey to boot from. If I can get
MSDOS on there by copying from a remote machine then I can boot the Slackware
installer from MSDOS and then install the rest of Slackware across the network
- talk about complicated!!)
Ok, long email - will shut up now! :-)
cheers
Jules