MS-DOS 6 has the classical 8.4gb disk limitation (1024*255*63*512).
You'd need to upgrade to Windows 98 for FAT32 support >32GB, and to install the R. Loew patch for 48-bit LBA to support >137GB.
You also need BIOS support for Int 13h Extensions and 48-bit LBA for which you could use disk overlay software or XT-IDE Universal BIOS.
Such a disk is quite "period-incorrect" and you may well be the first person in the world to try this on that series of Libretto.

jakethompson1 wrote on 2025-10-01, 02:33:

MS-DOS 6 has the classical 8.4gb disk limitation (1024*255*63*512). You'd need to upgrade to Windows 98 for FAT32 support >32GB, […]
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MS-DOS 6 has the classical 8.4gb disk limitation (1024*255*63*512).
You'd need to upgrade to Windows 98 for FAT32 support >32GB, and to install the R. Loew patch for 48-bit LBA to support >137GB.
You also need BIOS support for Int 13h Extensions and 48-bit LBA for which you could use disk overlay software or XT-IDE Universal BIOS.
Such a disk is quite "period-incorrect" and you may well be the first person in the world to try this on that series of Libretto.

Thanks for the hints; the major concern at this point seems to be the bios changes required to support large drives, as I doubt there is any patch made for the Libretto (I have a 50CT so the oldest of the bunch).

Could I install W98 and boot just in DOS and use that? The Pentium on the Libretto is barely working with W95, so I would exclude that it could handle W98 as is with its current hardware.
I think I can live with a 1 TB SD card partitioned in 32 GB chunks; that would be better than 2 GB I currently have for sure. I will just need to trim on the games I want to have and make 2 different SD cards that I can swap when I want to use some games.

Later versions of Windows 95 have MS-DOS 7.1, as well and can do FAT32.

theshinyknight wrote on 2025-10-01, 02:25:

Is there some trick to use large capacity disks on DOS6?

The trick is to install the large disk in a modern server, and access it from DOS6 via LAN.

I use Linux + Samba on the server side, and Microsoft Network Client on the DOS side.
There's only one problem: Microsoft Network Client occupies a lot of RAM - but it's probably not a problem for DOS-extender games.

I've also tried mTCP NetDrive.
It should work with any OS on the server side.
RAM usage is very low.
With DOS6, disk image size is limited to 2 GB - but you can keep infinite number of images on the server, and only mount the one you currently want to play with.

What I always did in DOS was to use removable drive carriers.

These go in a 5.25" front panel slot (like used for a CD or 5.25" floppy - usually 2-3 on older cases)
and have a pull out carrier where you can mount a drive...

They normally have screws to hold the drive and covers ... I usually put wooden dowels across
the bottom that I could just lay drives on, and left the top cover off (you don't see either if these
when it's in the system). Then I could just connect the drive cables and place the drive within -
very easy to chance drives.

On some newer systems that have SATA, I have the cables long enough to reach outside, and just lay
the drive through a flip-down opening (which some cases have for CDs) into a drive bay (sometimes
I have to make a thin wood/plastic bottom piece) - no carrier needed.

Well...you could try to compress the hard drive using DoubleSpace that comes with MS-DOS or Stacker or JAM. I believe Stacker and JAM produce better results, but JAM is very hard to use. After that, you can compress floppies and Zip disks and offload some programs on your hard drive to them. If you don't have a Zip drive, you should be able to buy one off of eBay. Just search for "iomega parallel zip100 drive."

A lot of games still have compressed assets after you unpack them from installation files or zips, so 1.4x to 1.6X compression is the best you can hope for overall, if it's all zips, it CAN sometimes take more space on the compressed volume than on uncompressed. By that I mean compression ratios like 0.98 so it's actually consuming more disk in the compressed volume file than it would just being on the disk.

Anyway, apart from trying to figure out massive numbers of partitions or massive partitions, there's games that will only install/run off C, games that don't like to be above 512MB on the disk or 2048MB and will probably trash it with saves because they're not totally going through the DOS hooks.

BitWrangler: you're right: some games may bypass DOS completely to access the drive, but AFAIK, most shouldn't, and some of the ones that do might still work from a Zip disk uncompressed.

How about NTFS driver?

Just use Win98SE / DOS 7.1 and format FAT32 partitions. Depending on the BIOS limitations of the Libretto you may need to install Ontrack drive overlay to raise the drive limit.

On machines that I cannot use XT-IDE ROM on (usually laptops, just like your Libretto), I use this to fit huge drives into older machines; all the way back to 386 systems. Most of the time I tend to fit mSATA to IDE adapters and 128GB mSATA SSD's, but occaisionally use => 120GB IDE drives, too. On desktops the XT-IDE ROM is still probably the better option than a drive overlay if you want to transfer data using Windows devices, but Ontrack partitions are automatically handled by Linux these days, so it's not so much of an issue compared to 5-10 years ago.

Works brilliantly. Of the ~60GB of DOS games installed on my 'image' that I squirt on to every new machine, there are only a single-digit-handful that have problems on large/FAT32 partitions; Lemmings 2 is one of the more popular ones which comes to mind. I tend to have a ~2GB FAT16 'DOS' C drive and the rest as a FAT32 'Games' D drive to handle this (very rare) issue. I've yet to find any show stopper issues.

BitWrangler wrote on 2025-10-01, 11:57:

Anyway, apart from trying to figure out massive numbers of partitions or massive partitions, there's games that will only install/run off C, games that don't like to be above 512MB on the disk or 2048MB and will probably trash it with saves because they're not totally going through the DOS hooks.

Another benefit of DOS7.1 - direct disk access by games/programs is locked out by default (you can use the lock/unlock command to change this.
Not included in DOS6.22 but it is in DOS 7.0, the original Win95 Dos that is still Fat16 only.

brotherdg2@gmail.com wrote on 2025-10-01, 14:42:

How about NTFS driver?

+1

There are HPFS (OS/2's NTFS) and FAT32 drivers, too! ^^
They're all using the network interface, like MSCDEX does for CD-ROM support.

PC-DOS 4 even had an IFS supported (installable file system)..
In principle, a FAT32 or exFAT driver could be written for it.

Also, there's an MS-DOS 5 patch that allows up to ca. 3 to 4GB partitions.
Not sure if it affected the 8GB HDD limit, though. FAT16 also wasn't very efficient at such partition size.

@Riikcakirds I remember UNLOCK from Windows 95 days.
I had to use it, in order to run COMPRESS on my HDD (FAT16 formatted).

Thanks everyone; went with using W98 DOS; although I won't use it for Windows at all but I can leverage the FAT32 IO at this point.

I may try the other solutions too, especially the NTFS, depending from how things go once I format multiple FAT32 partitions and see if DOS does not freak out 😀

You might need to edit lastdrive parameter in config or autoexec forgot which one it's in.... and maybe raise buffers value a bit, not sure if that helps it cache FATs and dirs... IDK shooting from the hip on vague memories of messing with more than 10 partitions/drives... it's stuff I would look up to check.

lastdrive= is in config.sys. 😀

LASTDRIVE is only necessary for drives controlled by .SYS drivers and .COM/.EXE TSRs.