What version of OS/2? OS/2 Warp 3 needs to boot inside the first 1024 cylinders.
Here's an older guide that might help get you started- https://www.abc.se/~pa/data/multi-op.htm

superpete wrote:

I have a 500GB disk in an early Pentium class machine that I'd like to quad-boot Windows 3.1/98. NT4 and OS/2. Fortunately the B […]
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I have a 500GB disk in an early Pentium class machine that I'd like to quad-boot Windows 3.1/98. NT4 and OS/2. Fortunately the BIOS can see the entire disk.

The scheme I have is as follows but am open to suggestions 😀

• PART1 - 2GB FAT16 MSDOS/Win3.1 (I assume the boot manager would also live on this partition?)
• PART2 - 40GB FAT32 Windows 98
• PART3 - 20GB HPFS OS/2
• PART4 - Extended Partition
  • Logical 1 - 40GB NTFS NT4
  • Logical 2 - Remainder FAT32 (Data)

Can NT4 be installed in an extended partition? I recall issues with it and disks greater than 8GB, I'm not sure if SP6 resolved it or not. What boot manager is recommended for these Operating Systems (years gone by I had good success with the OS/2 boot manager, but I assume things have improved since).

First of all, "BIOS can see" and "BIOS will allow me to use it" are two different things. According to my experience, 500GB is way huge for a Pentium (socket 7?) board and I really suggest you to check its "recognition" status more thoroughly.

The second thing is, as far as I know, NT based OSes will want to put its boot loader into the first active partition, even if you try to install it on a extended partition or even a second drive.

This would be my partitioning style:

First Disk :

1 - 2GB primary: Windows NT (cannot boot when installed beyond the first 8 GB)
2 - 2GB primary: OS/2 (depending on if it is patched up or not, will not boot when installed after the first 1023 cylinders)
3 - 2GB primary: MS-DOS/Windows 3.1
4 - X GB primary: Windows 98SE (120GB max)

Second Disk (data parititons):

An X GB FAT16 (2GB max)- must for MS-DOS which normally cannot see FAT32, NTFS and HPFS partitions.
An X GB FAT32 (120GB max) - must for Windows 98 which normally cannot see NTFS and HPFS partitions, and FAT16 might be too small.
An X GB NTFS (max?) - must for Windows NT which normally cannot see HPFS and FAT32 partitions and FAT16 partition might be too small.
An X GB HPFS (max?) - must for OS/2 which normally cannot see NTFS and FAT32 partitions and FAT16 partition might be too small.

I also strongly suggest masterbooter. It's support page is a good read for multibooting basics.

http://www.masterbooter.com/support/faq_en.html

As these system's are from the 90's era, they can be used with Os/2 boot manager. Other than that, go for "Extended Fdisk"
Os/2's boot manager (as far as I remember) can use up to 8gb harddrives.
Just play with them two boot managers, and remember that it is only there to change the "Active-Flag" and nothing else.
The biggest problem is, that IDE can only have 4 primaery partitions. This can be solved, by having a second HDD for Os/2.
As the bootmanager can boot from a second harddrive (slave), and use that drives primaery partition.

get a good boot manager like System Command, it will take a lot of the pains away of opsys's fighting for boot control + bootable flags and whatnot..

I had some time over the weekend to give this a go.

tayyare wrote:

According to my experience, 500GB is way huge for a Pentium (socket 7?) board and I really suggest you to check its "recognition" status more thoroughly.

Right you are, the drive seemed to be detected correctly by the BIOS but I couldn't use above 80GB (whcih seems weird I would have expected ~127GB). I dropped a PCI SATA Card in it and had no issues with a spare 1TB disk.

My structure is as follows:

• Primary 1 - 2GB FAT 16
• Primary 2 - 2GB FAT 16 (hopefully change to HPFS) OS/2
• Primary 3 - 40GB FAT32 (Windows 98)
• Primary 4 - Extended
  • Logical 1 - 40GB NTFS (I've put Win 2K on there for now)
  • Logical 2 - Remainded FAT32 Data

This was created with Extended FDisk. My installation was in the following order

1. Install DOS and Windows 3.1 on the first FAT16 partition (I've used Windows98 DOS for it's FAT32 support)
2. Format and sys Partition 3 and copy the Windows 98 Install files on to it
3. Boot off the Windows 98 partition with the Extended FDISK Boot Manager. Install Windows 98
4. Boot off the Win2k CD-ROM and install Windows 2000 onto the extended partition. It will install the NTBoot Manager on the first primary partition allowing you to boot Windows 2000 from that parition

I'm still struggling with OS/2 Warp 4. It won't let me select partition 2 in the OS/2 FDISK so I haven't been able to complete the installation. I suspect I should start with OS/2 then do the other operating systems.

superpete wrote:

I had some time over the weekend to give this a go. […]
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I had some time over the weekend to give this a go.

tayyare wrote:

According to my experience, 500GB is way huge for a Pentium (socket 7?) board and I really suggest you to check its "recognition" status more thoroughly.

Right you are, the drive seemed to be detected correctly by the BIOS but I couldn't use above 80GB (whcih seems weird I would have expected ~127GB). I dropped a PCI SATA Card in it and had no issues with a spare 1TB disk.

My structure is as follows:

• Primary 1 - 2GB FAT 16
• Primary 2 - 2GB FAT 16 (hopefully change to HPFS) OS/2
• Primary 3 - 40GB FAT32 (Windows 98)
• Primary 4 - Extended
  • Logical 1 - 40GB NTFS (I've put Win 2K on there for now)
  • Logical 2 - Remainded FAT32 Data

This was created with Extended FDisk. My installation was in the following order

1. Install DOS and Windows 3.1 on the first FAT16 partition (I've used Windows98 DOS for it's FAT32 support)
2. Format and sys Partition 3 and copy the Windows 98 Install files on to it
3. Boot off the Windows 98 partition with the Extended FDISK Boot Manager. Install Windows 98
4. Boot off the Win2k CD-ROM and install Windows 2000 onto the extended partition. It will install the NTBoot Manager on the first primary partition allowing you to boot Windows 2000 from that parition

I'm still struggling with OS/2 Warp 4. It won't let me select partition 2 in the OS/2 FDISK so I haven't been able to complete the installation. I suspect I should start with OS/2 then do the other operating systems.

I always have some sort of problem whenever I tried installing OS/2 (have some small amount of experience with both 3 and 4) that I need to revise my partitioning plan to make the problems go. I don't exactly remember what I really did each time, but I can suggest making other partitions "hidden" especially the partitions before OS2 partition. I actually can say that it is always good to make any other partition hidden while installing an (non-NT based modernish) OS in a multiboot system.

I can also suggest making the first partition an OS2 one, and moving the DOS to second FAT16 partition. Dos will boot from any partition in the first 8GB, as long as all the prior partitions are either hidden or unreadable (non FAT16).

500GB is a lot of space and you will run into the 134GB limitation in Windows 9x , other limitations in dos, I have found the sweetspot to be around 120Gig for most retro builds, it just has less hassles and worries.

That being said, use Plop boot manager, it is immensely powerful if you know how to use it right, and there is a bit of a learning curve, sadly I dont know how it will react with OS2 , but its worth experimenting.

Superpete, glad you're using OS/2 on that machine aswell!
You already got lot's of tips for your boot manager, so I've nothing much to add.
But I remember I've once used one with OS/2 Warp 3.0 long ago.. It was from Paragon, I think (it did that -hidden partitions- thingy).
I don't know if it's still good though, Plop boot manager and others are probably better.

Oh, and in case you encounter memory problems, here's a tip:
The BIOS setting "OS/2 Memory >64M" is only for old versions of OS/2.
For OS/2 Warp 3.0 and higher this should be set to "disabled" or "Non-OS/2".

And if you're have trouble loading drivers, here's another one: In OS/2, system files should be always in 8+3 format, so avoid long names.
I had this problem with the machine additions of virtualbox; everything was setup right, but they didn't load.
The reason was ofcourse the fact I was using a FAT volume inside my VM (so it can be opened with WinImage).
Eventhough OS/2 supports long file names on FAT, it doesn't support them during boot up. And after I shortened them, they worked.
I guess those -um- respectful developers seem to expect their customers to use HPFS only,
otherwise I can't think of any reason why they used long filenames for their drivers.
That's against the official OS/2 programming guidelines.

You're doing it the wrong way - the OS/2 boot manager must be put in first, and OS/2's fdisk used to partition the disk.

Note that none of the operating systems you mention can handle disks that large without updated drivers.

Disk layout :

Primary - OS/2 Boot manager (probably about 10MB, depends on geometry)
Primary - FAT16 - MSDOS/Windows 3.1. 2GB.
Extended - OS/2 HPFS boot. 400MB. Doesn't need to be any larger.
Extended - NT 4 NTFS boot. At least 500MB, a GB to be safe.
Extended - FAT32 (Win 98), whatever you want. Can't remember '95 limits, probably a driver to increase them.
Extended - NTFS
Extended - HFPS - OS/2 data. 20GB will handle any OS/2 app you care to mention, unless you're heavily into graphics.
Extended - more FAT32 if you want it.

Make sure that whatever size the OS/2 and NT boot partitions are, that the OS/2 boot manager offers the option of 'set installable' when run from the install program. This ensures the partition is entirely within the first 1024 cylinders and bootable.

DOS and OS/2 boot from their own partitions. NT 4 boots partly from the NTLDR files it will stick in the DOS partition, and partly from its system partition. Windows 98 will put some files on the DOS partition, and some on its install partition.

Order to install : 1) OS/2 boot manager. Optionally also OS/2. 2) DOS 3) Windows 3.1 4) Windows 98 5) Windows NT. NT will disable the OS/2 boot manager, it will be necessary to use an fdisk program to set it active again. There are drivers for OS/2 and NT that will handle large disks, these can be applied at install time, or after installation.

My retro system has at least DOS, OS/2, Linux, and OpenBSD on it. Can't remember what Windows versions I put on, but will check tonight.

Technically, yes, you can dual boot OS/2 on a FAT partition with DOS. You really, really, do not want to do so.

Why not install Windows 98 on the same FAT16 partition as MSDOS and Windows 3.1? 2GB is plenty of space for normal operation, and you can always install other stuff to the data partition if you need to. (Just make sure you don't touch anything with a long filename while running DOS.)

In theory, you can then have OS/2 and NT4 on primary partitions, and toggle between them just by setting the active partition without having to worry about the NT4 and OS/2 boot managers. (At least, I assume OS/2 works thay way.)

Realistically I suspect you'll only use NT4 and OS/2 for ten minutes and then forget about them forever, so you might want to just consider storing them on a second separate hard drive and saving yourself the headaches.