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Why would Linus build a Linux/Unix for x286

Well there is a simple answer to that... He didn't. The first version of linux was written for the 80386. A quote from Linus himself... His announcement of linux:

Hello everybody out there using minix -

I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones. This has been brewing since april, and is starting to get ready. I'd like any feedback on things people like/dislike in minix, as my OS resembles it somewhat (same physical layout of the file-system (due to practical reasons) among other things).

I've currently ported bash(1.08) and gcc(1.40), and things seem to work. This implies that I'll get something practical within a few months, and I'd like to know what features most people would want. Any suggestions are welcome, but I won't promise I'll implement them :-)

Linus (torvalds@kruuna.helsinki.fi)

PS. Yes - it's free of any minix code, and it has a multi-threaded fs. It is NOT portable (uses 386 task switching etc), and it probably never will support anything other than AT-harddisks, as that's all I have :-(.
—Linus Torvalds

If you scroll up, you will see that I said the 80286 had protected mode. How is it that you can't read? One of the things (of many) that made the 80386 different from the 80286 was that it could enter and exit protected mode without having to completely reset. Sure, there were other big architecture changes as well, like 32-bit registers, and a MMU that could do page level protections instead of segment level protections like the 80286. But the 80386 was the first intel chip that could (and still can really) run a modern operating system.

The 68000 didn't have a protected mode either. It kind of had a user/supervisor mode, but since the MMU wasn't integrated, it depended heavily on external chips to implement most of the functionality. That wasn't implemented until the 68010 or 68020 I believe (Maybe even 68030). And yes, I wrote a lot of 68xxx code as well as x86 code. I actually started on 6502 -> 68000 -> x86. Haven't done any ARM programming, but I try and keep up with the different architectures. I've run/used Windows on x86, ARM, Alpha, and MIPS. I haven't written an OS for anything other than the x86, but I did a lot of systems programming on the 6502 and 68000 (and x86), including multitasking when the OS wasn't multitasking itself. The concepts aren't all the much different.

Here's an online magazine from 1990 that highlights a shareware project I did on the 68000 in assembly (YMG), in the background. On an OS that didn't support multitasking, and using hardware devices (RS232 port): https://atarimax.com/freenet/f...

I'm too lazy to go googling, but I'm sure you can find references on the web to some of my past projects.. Super fast disk defragmenters, bulletin board systems, file transfer protocols, multi-user systems, online multiuser gaming systems, multitasking/multiprocessing systems for DOS, windows device drivers, proxy servers, conversations with the w3c groups on html and css specs, etc etc. I'm a pretty decent programmer, and I've been around enough to know a lot of things about a lot of esoteric things.

And you?

I still have a 1200XL lying around and was thinking of doing something similar to what this guy did: I couldn't imagine trying to make the old 1050 disk drive work

While the laptop version is a cute hack I wouldn't bother. I still have an 800XL connected and running with a 1050 (it still works too - they, and 5 1/4" disks are plentiful on ebay and other sources) but you would want something called APE for real storage - it uses your PC serial port and emulates all kinds of devices. And the interface is near trivial - you can solder one together from Radio Shack parts. Tons of Atari software will fit on one CD. I just startup APE, turn on the 800XL and have more games at my fingertips (all w/o bothering with floppies) than I know what to do with.

You can get started with programming in Basic, and can also play a ton of games.

P.S. Steve Tucker at AtariMax.com has a bunch of cool toys for the 8-bits, including flash carts.

You can get started with programming in Basic, and can also play a ton of games.

P.S. Steve Tucker at AtariMax.com has a bunch of cool toys for the 8-bits, including flash carts.

I've made redundant copies (some games on as many as three different floppies) just in case a disk goes bad.

Atari enthusiasts have some called the Atari Peripheral Emulator that allows your modern day PC serial port to act like a floppy disk drive. That way, we can keep 'tons' of old software on CD-ROM, load and boot up F-15 Strike Eagle, Blue Max, Raster Blaster or Kennedy Approach ;) Software on a real floppy can easily be copied to the PC, and archived on CD's etc.

That company should be a study in how NOT to run a business, 10 yrs growth to build a brand name up there with Coke, then 10 years steady decline to oblivion. Bushnell cashed out just a little too early, Warner couldn't manage it, then Jack Traimel made a valient attempt, and eventually got the Swordquest prize over his fireplace.

Anyway, I was happy to find a 1979 Sears 'wishbook' with the Atari 400 in it. Also, the way to run a classic Atari 800(XL) system today is use the APE (Atari Peripheral Emulator), run it to your PC serial port, then you can mount disks from a PC and have tons of Atari software (my entire collection fits on a CD) at your fingertips. It also daisy chains with a normal 850/1050 fdd if you need to get data on/off 5.25" floppies.

Personal faves: Blue Max, Kennedy Approach, etc.