off topic: Re: booting DOS

["J. R. Fox" jr_fox@xxxxxxxxxx]

On Sept. 6, jxz@xxxxxxxxxxx wrote:

> Myron Gochnauer wrote:
>
> > I would be interested in learning how you boot DOS that
> > is not near the beginning of the disk (or within the first
> > so-many sectors or something). I thought that was a
> > limitation even for things like Win2K.  It might be nice
> > to have a small real-DOS partition somewhere on my hard
> > disk.
>
> There is a possibility of getting dos to boot from a
> partition which starts beyond 2Gb (the limit to its usual
> capacity) but I haven't tested it exhaustively.
> I do it on a 10Gb disk where the 2Gb dos partition
> starts about 5Gb in from the origin.
>
> All one does is create & format the partition then run a
> program which patches it (I'm not sure where the patch
> takes - on the boot or partition sector I imagine).

I think I may have initiated this discussion a while back, in the thread
entitled "Enhanced DOS." I just discovered this message from early in the
month, which I must have missed previously. In the interim, I found out that
both Western Digital and Seagate (not Adaptec, as I mentioned earlier) have
drivers to accomplish much the same thing. Both are apparently free, but you
must request the one from Seagate. I have not yet tried any of these,
including BOOTFIX, which you attached to your message.

> That sounds easy but of course fdisk makes it difficult if
> not impossible (it won't normally allow 2 primary
> partitions on the same disk IIRC).

No, the limit is 4 Primaries. One of these will be the Extended Partition
"wrapper" that contains all of your "logical" partitions. That being said, on
the system I am currently assembling, Partition Magic shows a "fifth" Primary
at the start of Unallocated space at the back of the drive, which I don't
quite understand. Maybe this is just a display glitch ? In any case, your MS
opsyses from DOS up through W98 insist on being in a C: Primary. According to
some docs I just read, W98 insists on being in the *first* C: Primary. I hope
that is not strictly true, as it would toss a minor monkey wrench into the
partitioning scheme for this box.

Also, I'm finding that I might prefer DR-DOS 7.03, now getting a tryout in the
(normally Hidden) alternate C:, over the IBM PC-DOS 2000 I had been using for
a long time. The one problem I've run into is that I can't get into the W2K
boot loader from there. I tried to clone the boot loader setup from the first
C:, into the alternate C:, but it just doesn't work, probably because there is
*coded* location-specific info somewhere in the loader files that I don't know
how to hack. It might be a bit arcane for this list, but if anyone has
finessed this issue, please let me know. I don't want to go back to System
Commander, which could probably handle the matter, because it may not respect
or be compatible with the LVM system that current issue OS/2 now relies upon.

> The fix will let you boot Linux or FreeBSD from
> partitions above 8G, however it will not make magic and
> boot DOS from the end of 60G disk."
>
> There is another program though which offers a similar
> patch - Bootfix. I simply run it from floppy, with the
> disk to modify being c:. It does all that's needed.

The driver patches I mentioned are really to allow DOS to see out beyond the
8G. "barrier." I doubt that booting DOS that far out is really going to be
possible. My guess is that BOOTFIX temporarily (?) fudges what is considered
the C:, probably at the cost of messing with your drive lettering scheme ?
I'll experiment with it when I get the chance.

Jordan


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>          Name: BOOTFIX.zip