CRD covered a boot manager for DOS/Win9x little while ago, it uses the GRUB.

https://www.youtube.com/watch?v=f6gEDUigoXw

Out of curiosity, why are you looking to multiboot DOS, WIN95, and WIN98? Are there any specific programs that only work on 95 and not 98? Is this just to experience the differences between the OSes?

I second GRUB. It's used with Linux. In case you didn't know, Linux is unequivocally the only usable thing for anything and anyone. You should try it!

Sorry. Had to tease you after seeing your other post (-:

Ensign Nemo wrote on 2024-01-24, 18:04:

Out of curiosity, why are you looking to multiboot DOS, WIN95, and WIN98? Are there any specific programs that only work on 95 and not 98? Is this just to experience the differences between the OSes?

I'm currently experimenting with a build to see how much reasonable overlap with hardware can be achieved with different OS from DOS to XP. This is stemming from this other discussion here: What is the fastest practical DOS build?

Since I plan to do this with a 1 TB drive, I've got ample space for extra partitions for DOS and Win 95.

Putting aside the boot manager for a second - I don't 100% remember off the top of my head whether the hdd size limits were about partition sizes (addressing relative to the start of the partition), or absolute hdd sizes (addressing relative to the start of the device) but I think it's the latter. You might want to look into that, since you might need to adapt (e.g. win98 max 128gb -> w98 partition size (128-32-2) = 94gb so as not to go beyond the 128 marker on the hdd). Oh and subtract a few more sectors used by the MBR too... Or use rloew's limit removing patches and do whatever.

Now, back to the original topic.

elszgensa wrote on 2024-01-24, 18:50:

Putting aside the boot manager for a second - I don't 100% remember off the top of my head whether the hdd size limits were about partition sizes (addressing relative to the start of the partition), or absolute hdd sizes (addressing relative to the start of the device) but I think it's the latter. You might want to look into that, since you might need to adapt (e.g. win98 max 128gb -> w98 partition size (128-32-2) = 94gb so as not to go beyond the 128 marker on the hdd). Oh and subtract a few more sectors used by the MBR too... Or use rloew's limit removing patches and do whatever.

Now, back to the original topic.

This is a good point. I have a system that multi-boots 9 operating systems using 3 drives and getting all of the partitions in the right place to satisfy all of the operating systems... let's just say it was a challenge.

There is also the issue that you can't have more than 4 primary partitions with MBR on a drive. One can be extended and contain many logical partitions, but I don't think you can boot any of those OSs from a logical partition (correct me if I'm wrong please!). So as far as I see it you have one operating system too many to fit on a single MBR drive.

I'm a big fan of PowerQuest Bootmagic because it's what I've always used. The downside with it is you can only hide primary partitions, which might be a concern if you want to hide some of your small FAT16 partitions from say your XP install.

elszgensa wrote on 2024-01-24, 18:50:

Putting aside the boot manager for a second - I don't 100% remember off the top of my head whether the hdd size limits were about partition sizes (addressing relative to the start of the partition), or absolute hdd sizes (addressing relative to the start of the device) but I think it's the latter. You might want to look into that, since you might need to adapt (e.g. win98 max 128gb -> w98 partition size (128-32-2) = 94gb so as not to go beyond the 128 marker on the hdd). Oh and subtract a few more sectors used by the MBR too... Or use rloew's limit removing patches and do whatever.

That's good information to have.

If that's the case, I can easily adjust partition sizes to fit within those limits. And if I need to put the extra DOS FAT16 extended partitions upfront as well, I can do so.

So something like: 2 (FAT16) + 2 (FAT16) + 2 (FAT16) + 16 (FAT32) + 100 (FAT32)

Shadzilla wrote on 2024-01-24, 19:31:

There is also the issue that you can't have more than 4 primary partitions with MBR on a drive. One can be extended and contain many logical partitions, but I don't think you can boot any of those OSs from a logical partition (correct me if I'm wrong please!). So as far as I see it you have one operating system too many to fit on a single MBR drive.

I'm planning only 4 operating systems, so that should work, shouldn't it?

I'm a big fan of PowerQuest Bootmagic because it's what I've always used. The downside with it is you can only hide primary partitions, which might be a concern if you want to hide some of your small FAT16 partitions from say your XP install.

Keeping them exposed to the other systems might be okay, since it would let me transfer files between operating systems.

Shponglefan wrote on 2024-01-24, 20:18:

I'm planning only 4 operating systems, so that should work, shouldn't it? […]
Show full quote

Shadzilla wrote on 2024-01-24, 19:31:

There is also the issue that you can't have more than 4 primary partitions with MBR on a drive. One can be extended and contain many logical partitions, but I don't think you can boot any of those OSs from a logical partition (correct me if I'm wrong please!). So as far as I see it you have one operating system too many to fit on a single MBR drive.

I'm planning only 4 operating systems, so that should work, shouldn't it?

I'm a big fan of PowerQuest Bootmagic because it's what I've always used. The downside with it is you can only hide primary partitions, which might be a concern if you want to hide some of your small FAT16 partitions from say your XP install.

Keeping them exposed to the other systems might be okay, since it would let me transfer files between operating systems.

You can only have four partition entries on an MBR partition table.

That means four primary
or three primary & extended, the extended one can in turn again have four more partition entries, i think... it's been too long.

weedeewee wrote on 2024-01-24, 20:34:

You can only have four partition entries on an MBR partition table.

That means four primary
or three primary & extended, the extended one can in turn again have four more partition entries, i think... it's been too long.

Ah, I misunderstood the prior post. I get it now.

The extended partition isn't necessary in this case so I can do without.

System commander.

I used SBM twenty years ago and would probably use it again on a retro machine.

Ensign Nemo wrote on 2024-01-24, 18:07:

I second GRUB. It's used with Linux. In case you didn't know, Linux is unequivocally the only usable thing for anything and anyone. You should try it!

I run Linux on a Raspberry Pi, does that count? 😉

Sorry. Had to tease you after seeing your other post (-:

😁

(I will check out GRUB though.)

Shponglefan wrote on 2024-01-25, 00:53:

I run Linux on a Raspberry Pi, does that count? ;) […]
Show full quote

Ensign Nemo wrote on 2024-01-24, 18:07:

I second GRUB. It's used with Linux. In case you didn't know, Linux is unequivocally the only usable thing for anything and anyone. You should try it!

I run Linux on a Raspberry Pi, does that count? 😉

Sorry. Had to tease you after seeing your other post (-:

😁

(I will check out GRUB though.)

Running it on your pi is a good start. It's only a matter of time until we get you to migrate your other machines to Linux (-:

Thanks for all the suggestions so far.

I'm currently rethinking my partition strategy to split the operating systems on two drives as follows:

1 TB SSD:

C:\ 16GB FAT32 - Windows 95 (Primary)
C:\ 100GB FAT32 - Windows 98 SE (Primary)
C:\ 500GBNTFS - Windows XP (Primary)

4 GB CF Card:

C:\ 2GB FAT16 - DOS (Primary)
D:\ 2GB FAT16 (Extended/Logical)

Since each drive would have its own MBR, I'm assuming this should work. I could then add an extended partition to the main 1 TB drive if I wanted to.

Any feedback on this?

weedeewee wrote on 2024-01-24, 20:34:

You can only have four partition entries on an MBR partition table. […]
Show full quote

Shponglefan wrote on 2024-01-24, 20:18:

I'm planning only 4 operating systems, so that should work, shouldn't it? […]
Show full quote

Shadzilla wrote on 2024-01-24, 19:31:

There is also the issue that you can't have more than 4 primary partitions with MBR on a drive. One can be extended and contain many logical partitions, but I don't think you can boot any of those OSs from a logical partition (correct me if I'm wrong please!). So as far as I see it you have one operating system too many to fit on a single MBR drive.

I'm planning only 4 operating systems, so that should work, shouldn't it?

I'm a big fan of PowerQuest Bootmagic because it's what I've always used. The downside with it is you can only hide primary partitions, which might be a concern if you want to hide some of your small FAT16 partitions from say your XP install.

Keeping them exposed to the other systems might be okay, since it would let me transfer files between operating systems.

You can only have four partition entries on an MBR partition table.

That means four primary
or three primary & extended, the extended one can in turn again have four more partition entries, i think... it's been too long.

I'm pretty sure you can have virtually unlimited extended partitions. Think of it in terms of the main extended partition being split into two, the second of which is in turn split into two, and so on.

https://en.wikipedia.org/wiki/Extended_boot_record tells you more about extended partitions and the logical drives they contain. Each logical drives partition record (much like the physical drive's MBR) contains a pointer to the next logical drive.

Shponglefan wrote on 2024-01-30, 22:22:

Since each drive would have its own MBR, I'm assuming this should work.

Any feedback on this?

Do note that doing it this way, you'll be going through the BIOS' boot device selection a lot, which you may or may not mind. If you do, you need to pick a bootloader than can "jump" from one device to another (say, BIOS loads bl from HDD, which would then need to pivot to CF if you want DOS). Fwiw, Grub can do this no sweat; no clue about others.

System Commander is very hacky. Check the CRD video posted above to see that in action. Boot Magic is far superior. I use V7 (I think) on my Dos 6.22/Win 95/Win98SE machine and it's very slick and period correct.