I'm already learning Linux, having dedicated my SSD to it, and am booting Windows 10 on an external HDD. I really cannot think of any other OSes that are worth my time to learn, except maybe one of the BSD variants (most likly FreeBSD), and Hackintosh/OSX. This brings me to the question of the ancient DOS. Is it really still useful today in our modern age? I'm thinking that focusing on Linux is my best bet. I would mainly like to try DOS for the learning experience and maybe to install some old games like Doom, King's Quest series, Hexen, Heretic, etc. (although the latter can be easier played with DOSBox or D-Fend Reloaded, I don't mind learning to manually configure them to work properly).
Which now brings the question of original, pure MS-DOS vs a clone like FreeDOS. The former has been largely abandoned, whereas the latter is actively developed. I'm not so much concerned with getting a purist DOS experience, I mostly am just interested in the basic concepts. Original DOS may not boot so well on modern hardware, whereas FreeDOS is more compatible and has improved utilities and better hardware support. What are the chances of getting original DOS running on modern hardware? I had recently tried to boot XP and Hirens on my ultrabook, but got an ACPI error that stopped booting cold, so if that is any indication........There is also the issue of which version of DOS to use, probably 6.22 since it seems to be the widest supported and most commonly used, whereas FreeDOS only has one main version worth considering. And pure DOS is proprietary whereas FreeDOS is open source, although I've never been one to make decisions based primarily on ideologies, I prefer to choose the whatever that gets the job done most effectively and efficiently with the least amount of hassle. In other words, "just works" and by "whatever is necessary".
The next concern is booting on real hardware vs a VM. VM is safer and isolated, but works with virtualized hardware, which gives no indication of performance on real hardware. And isn't optimal for video performance in games. My ultrabook isn't exactly built for VMs, and I want optimal performance, so I think native booting on real hardware is better. As long as I don't try to run utilities that have direct disk editing abilities, the chances of destroying my partition table are slim to none.
What about booting on an SSD, speed won't be a real issue, and neither will write cycles, given DOS's small size. But I don't think that TRIM will be possible except in an OS that supports it. Does TRIM work on an OS level, affecting only the OS and its' related partitions, or on the whole drive?
Can DOS be installed to/booted from a logical partition, or is a primary necessary? I assume that it can. What about GRUB2, will it detect DOS/FreeDOS and add a entry accordingly? Do I need the format the OS partition as FAT32, or FAT16 (the former is preferred for performance reasons)? What about partition size? I need something that will be more than big enough for the OS, utilities, and some games. I have a 17GB torrent that consists of almost every DOS game ever released, but I don't think I'll be needing 20+GB. I'll simply install one at a time as desired.
I can't really think of any other questions, so if someone has suggestions, put them forth.