Did you had luck with newer motherboards and DOS? I've seen IDE compatibility mode for SATA removed and DOS can't access disks even for diagnostics, like Victoria HDD.
And what use cases do you have in DOS that can't be done in Windows/Linux Live CD?
Never had a problem yet except for UEFI boards which have no legacy CSM. Except some of the truly well-engineered UEFI firmwares do boot from a FAT32 external MBR volume. Otherwise no DOS for you.
Just use CSM and leave it in SATA mode and the A: drive, plus FAT volumes on HDD/SSD's are accessible and enumerated conventionally as C:, D:, E:, etc. according to legacy hierarchy on each boot. Remember to have all but one of your primary partitions hidden per HDD while in DOS. Carefully go wild with logical volumes often beyond 120GB offsets.
For best reliability I like to format FAT volumes using the MSDOS from Windows 98SE, only up to 32GB, especially to format USB sticks. Above 32GB I use NTFS and format using Windows 11. Alternatively the long-lost Iomega fat32 formatter would go way beyond 32GB using alternative cluster size far more reliably than Windows ME which was made for 64GB max. Always use the Scandisk fom W98SE, not WinME DOS for anything. Sometimes partiton in DOS FDISK too but more often using good old Linux Mint 9. Mint 10 is just as good for partitioning, but mkfs vfat declined in useful granularity at that point. Remember the live distro of Mint 9 doesn't support USB3, so use a USB2 socket for that. Etcher just doesn't cut it by comparison, use Rufus if you can't do it manually on your own. Most often zero whole drives before partitioning, and zero whole partitions before formatting. Much better off without pre-existing stray boot sectors, FATs or MFT's scattered around in the middle of your volume to take your data by surprise. Also many USB sticks formatted from the factory have a defective location for the backup volume boot sector if there even is a backup. Microsoft dropped the backup boot sector themself when formatting FAT32 with the release of XP, seems likely intended to compromise FAT32 reliability and make slower NTFS seem more acceptable when pushed into the mainstream back then.
Things like Windows XP or older won't install or run in SATA mode without a proper driver floppy for F6'ing, that's when it's easier just to use IDE mode sometimes. Also can be more challenging to add SATA drivers after installing though, and you usually end up pointing to the same files the floppy has on it.
Also the undocumented DOS command FDISK /MBR writes the high-reliability DOS MBR to sector 0 of your "master" HDD, of course without touching the partition table. This can only be accomplished from floppy.
Then DMDE disk editor has a DOS version made to run from floppy. Careful usage up to 120GB often but usually just access sector 0.
Things like Battle Chess or Tetris need no introduction, people can be highly amused booting & running it from a floppy whether or not a PC has any other drives or not. I'm partial to the DOS versions of the old 3M Bookshelf board game Acquire, all about investments, shareholders and mergers. Everyone prospers (at the end the bank might even run out of the originally provided paper currency, and you certainly will endure zero cash yourself before recovering during play) so it's more fun than the appropriately named Monopoly, plus it always goes to a direct ending usually in an hour or less. Most money-making person still wins.
>Things like Windows XP or older won't install or run in SATA mode without a proper driver floppy for F6'ing, that's when it's easier just to use IDE mode sometimes. Also can be more challenging to add SATA drivers after installing though, and you usually end up pointing to the same files the floppy has on it.
JFYI, as long as you have the actual driver files, and the motherboard can boot from a USB stick, you can use a "virtual" floppy via Syslinux or grub4dos for loading the F6 driver during setup:
Thanks for this jaclaz, always good to see your messages.
Might even work from a non-bootable USB stick formatted by MSDOS or Windows as a floppy (no MBR or partition table, same sector 0 as a floppy) if the BIOS recognizes it as A: (maybe also as B:) when plugged in before powerup.
Assuming the PC is booted to the XP CDROM or one of the other effective ways to conventionally install XP.
For XP I do like having both IDE and SATA drivers installed in the long run so it will still boot regardless of BIOS HDD mode setting.
Ideally when the BIOS would be set to boot from floppy with first priority, if a floppy was in the drive but had no boot files, the next boot device would then be tried.
With USB sticks - generally speaking and particularly with older hardware - bootability is "pure madness", the BIOS may want a partitioned or unpartitioned device, may have limit on the size of the device (i.e. 2 GB boots, 4 GB or bigger doesn't), may "like" (or not like) a given MBR or bootsector code, it is a mess.
In the good ol' times there was the makebootfat "special" setup, with the same stick that was at the same time partitioned and unpartitioned, then there was the "triple boot MBR" by Tinybit (one of the Authors of grub4dos) and FBinst (by Bean, another contributor to grub4dos) to workaround some of these BIOSes limitations/strange behaviours.
Often a non-bootable USB stick connected to the system is not mapped at all by the BIOS, but - again it depends - the grub4dos internal USB stack or chainloading a PloP might reveal it.
I need to check out DMDE disk editor, because the last disk editor in DOS that I used was an old copy of PartitionMagic with Win9x-like interface.
Also, I remembered that old boards without UEFI rarely came with a flash utility inside BIOS, so you need to boot to DOS and use AMIFLASH or some other utility to update it.
I might have encountered a defect in version 4, sticking with 3.6 for now, get it while you can.
I used to use partition magic too.
For UEFI it's good to become familiar with "the" EFI Shell, many versions exist, not always the best one is built into the mainboard firmware, if any. All named shellx64.efi
>The EFI Shell is a "shell" (think of a command prompt or a terminal shell) that a (U)EFI BIOS can boot directly into (instead of your OS), allowing control and scripting of many items including booting scenarios.
>Installing[0] an EFI shell in an "EFI System" partition (type EF00) formatted with a VFAT file system and properly named shellx64.efi for a 64-bit system will allow you to boot directly into it from your BIOS.
[0] copying shellx64.efi to the root of a FAT32 EFI volume
3.5 mm to 3.5 mm cable with decent length would be nice to have if you need to hook up a laptop/phone to speakers.
A spare PC power cord and a figure 8 cable would also be nice. I've seen many cheap cables that caused sparks because of a bad plug. One millimeter off and computer shuts off.
One Philips PH02 screwdriver if you ever need to clean a PC or change SSD, memory, etc.
For the software: for Windows side you can use Hiren's BootCD (you can use USB drive despite it's name). It doesn't contain pirated software as Sergei Strelec WinPE.
As for Linux - well, you can use Ubuntu's Live USB/DVD to be able to get a running system in minutes to recover files or do other stuff.
And what use cases do you have in DOS that can't be done in Windows/Linux Live CD?