View Full Version : Multibooting DOS/windows and Warp 3

April 10th, 2014, 08:18 AM
Pardon me if I'm repeating myself. I feel like I made a thread like this once before but my records say otherwise...

So for a variety of reasons I need to have a machine running where one partition runs PC-DOS 7 and Windows 3.11 and the other partition runs OS/2 Warp 3 and you select which OS you want to boot from after POST. The Warp side is formatted HPFS and the DOS side is FAT with the read-only HPFS driver, which you can find here (http://www.student.nada.kth.se/~f96-bet/ihpfs/).
I believe that I need my blue spine install set for OS/2. While I have it on CD it's upgrade-only unless there's a way to fool it so I'm stuck with the bajillion floppy disk version.
My big question is how the bootloader is installed. With DOS installed first, will Warp detect it and ask if I want to install the bootloader or is that a post-install thing?

April 10th, 2014, 08:29 AM
This should cover it. https://groups.google.com/forum/#!topic/comp.os.os2.apps/R_H0stwvalY

To quote Rod Smith:

"I often see people mentioning that they set up their HD to boot either
: DOS or WARP. How is this done -- I don't own WARP yet and probably will
: soon, right now I've got one partition only. Does this mean I should
: partition the drive? Does OS/2 have a multi-boot utility?

This is done in one of two ways, and the answer to your subsequent
questions differs depending upon the method used:

1) Dual Boot. This is the default method, and if you get REALLY nit-picky,
doesn't actually do what you say. Specifically, you can't choose which
OS to boot when you power on the computer [which I infer from the words
"...to boot either DOS or WARP..."]; you boot into whichever OS you last
used, and can then run a program to boot the other OS. In Dual Boot,
both OS/2 and DOS reside on the C: drive, so the typical new user
doesn't need to re-partition.

2) Boot Manager. This method does require re-partitioning. DOS goes on
drive C:, OS/2 goes on any other partition, and a 1MB partition is
created for Boot Manager itself. The computer technically boots the
Boot Manager partition, which pops up a menu that allows you to select
which OS to boot (DOS, OS/2, or anything else on the machine). The
Boot Manager then passes control to the boot routine of whichever OS
you selected.

In general, Dual Boot is easier to install but more difficult to use,
since you can't select which OS to boot at power-on time. Dual Boot is
also a bit more dangerous to use, since it mucks with the partition's
boot information with every OS switch, and if a disk error strikes at
that time, you can have a VERY BAD situation on your hands. (This is
rare, but a few people have encountered it.)

Personally, I prefer Boot Manager; but the hassle of installing it may
not be worth it for many people, particularly those who aren't sure if
they'll be keeping OS/2. It is possible to re-install OS/2 with Boot
Manager after gaining some experience with OS/2 using Dual Boot, and this
can actually result in better decisions about partition size and whatnot
than would be the case going straight to Boot Manager. (It's also
possible to go from Boot Manager to Dual Boot, of course.) Switching can
be a pain, of course, but no more so that re-partitioning for Boot
Manager in the first place. So use whichever you're more comfortable with

There is a utility available, called FIPS, that will shrink a FAT
partition, thus making room for new partitions and Boot Manager. This
utility does have disadvantages (namely, it doesn't change the allocation
block size, it requires that the drive be defragged first, and of course
any such modification is bound to carry some risk), but it's worth
considering, especially if you just want to squeeze out enough space for
Boot Manager and an OS/2 boot partition. Because of the allocation block
size issue, I wouldn't recommend using FIPS to, say, shrink a 300MB
partition to 100MB. An OS/2 utility to do this and more (including
converting FAT to HPFS without data loss) was recently announced, but
it's not available yet and will cost over $100, if I recall correctly.
(FIPS is either shareware or freeware, I don't recall which, and is
available from the usual DOS ftp sites.)

--Rod Smith"

April 10th, 2014, 08:29 AM
There are plenty of motherboards with BIOSes that give a boot menu on startup to do this. The catch is you need a separate drive for each OS. This method is easy and it requires zero additional setup/software. Guess that's too easy , eh? :-) I have several K7S5A boards that do this.

April 10th, 2014, 08:34 AM
I'm dealing with a PS/2 so I'm stuck playing by IBM's rules. ;)

April 10th, 2014, 08:46 AM
One of a multitude of reasons I don't have any PS/2s. :-)

April 10th, 2014, 08:48 AM
OS/2 Warp should include a boot manager that installs a a tiny hidden partition to do exactly what you want.


April 10th, 2014, 08:55 AM
Quite nifty for the time too. The user manuals have a section dedicated to setting it up.

Agent Orange
April 10th, 2014, 08:57 AM

If all else fails, a simple way to do what you want is System Commander. http://www.avanquest.com/USA/aq-you/support/obsolete_releases.html

If you have a problem with the download I have version 4.02

April 10th, 2014, 09:02 AM
xosl will do the job as well http://www.ranish.com/

April 10th, 2014, 09:02 AM
The drawback to using boot manager is that you have to know what sizes to make all the partitions first. A secondary problem is that DOS won't see the other primary partitions on the same drive.

MCA SCSI controllers often have options to switch the bootable drive which makes things simple if you have multiple drives.

April 10th, 2014, 10:42 AM
Right, it's slowly coming back to me now.

A secondary problem is that DOS won't see the other primary partitions on the same drive.
This is true only if you have both DOS and OS/2 in primary partitions. If you put OS/2 in a logical partition it will assign itself to D: but then you can share files between disks.

So re-reading the manual for Warp I first made a 476mb partition and installed DOS on that, then I started the Warp installer, added the 1mb boot manager partition, added the 477mb OS/2 partition and added both partitions to the boot manager so that I could choose either and if I didn't choose, it would boot DOS after a few seconds.
I'm in the middle of the floppy install for OS/2 so I can't immediately see if it worked but I'll report back when this is done.

Edited: Yep. That seems to work.

Agent Orange
April 10th, 2014, 02:25 PM
The drawback to using boot manager is that you have to know what sizes to make all the partitions first. A secondary problem is that DOS won't see the other primary partitions on the same drive.

MCA SCSI controllers often have options to switch the bootable drive which makes things simple if you have multiple drives.

If memory serves me correct, OS/2 Warp should load in less than 100 MB. Why would DOS need to see another primary partition anyway when you can use the rest of the HD as a secondary partition for shared files? I've run 3, 4, maybe more systems via System Commander in the past with no problems. Push comes to shove, use another HD.

April 10th, 2014, 08:47 PM
It's for isolation reasons in this particular machine. Otherwise I would of used my red spine install set and not bothered multibooting.

April 11th, 2014, 12:44 AM
Good stuff. Do you intend to go the whole hog with networking etc?

April 11th, 2014, 03:00 PM
I already have an Etherstreamer 32 installed with Windows for Workgroups 3.11. I still need to fine tune various things however like drivers and variables.