Comment by ghaerr | Hacker News Reader

Comment by ghaerr | Hacker News Reader

Thanks for the comments! ELKS will run on an 8088, but also runs on any x86 PC using the legacy "real mode" which runs in 16-bit segmented architecture without an MMU or any hardware protection. It can be fun to boot a PC and see a close resemblance to Linux, but run the way things used to be, using only 16-bits.

It'll also run in ROM, e.g. using a 8018x CPU w/onboard PIT and PIC.

The point of ELKS today is about "small is beautiful" and seeing what can be done when limited to 64k code and 64k data, and 640k RAM. It's based on a very old fork of Linux and many of the internal structures are similar to what was found in Linux 2.0, without the changes for SMP support.

We just recently got a native C compiler/assembler/linker toolchain up and running. I must say making that happen provided some vivid comparisons of what programmers had to go through in decades past in both slower speeds and small executable file sizes, versus what we all have and expect today at our fingertips.

Very awesome work indeed... I haven't looked at ELKS in a long time and seeing everything it can do now is heartwarming.

The 8018x/ROM mode sounds like it could make for a fun breadboarding project, not that I'll likely wind up doing it myself. Is there any way to run it in emulation?

Running native compilers on XT/286 hardware does indeed sound sloooow. At least it can be tested, probably automatically, in emulators where it'd run faster than the native compilers did back when this all started :)

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It's funny... 7-10 year old hardware back in 95-96 when this started could barely keep up with current software at all, and I'm writing this on a 7 year old Dell Precision (albeit upgraded well beyond stock :) ) that still runs Linux pretty darn well.

- Chad

There's a couple of ROM versions, one which runs with a ROM filesystem and boots a shell over serial and another which uses BIOS INT 13h calls for an external MINIX or FAT filesystem. Both are run using an emulator which allows selection of ROM address, RAM size, etc. It'd be too hard to develop reliably without emulators for any of our images.

And yes the native compilers are running way faster under emulation than the originals on real hardware! Funnily enough, we're finding the slowest portion of the native toolchain is the assembler, due to lots of symbols and slow hashing.

If you go back 15 years, to January 2010, you find x86-64 hardware that you could install modern Linux on as easily as running the installer off a USB stick. The unibody 2009 MacBook Pro was out by then, so your computer could even look totally normal at a Starbuck’s today (and connect to the WiFi just fine). That machine will take 8 GB of RAM and run the COSMIC desktop written in Rust for Wayland (run it well-I have done it).

Go back another 15 years to 1995 and you have Pentium desktops. Linux was created just a few years earlier for similar but even more modest hardware (as was Windows NT). Not every modern Linux distro will still run on Pentiums but many will. You may have to burn a CD but up-to-date Antix, Q4OS, or Adelie releases will still work out of the box. Certainly NetBSD will. Not everything will still run on 32 bit machines and RAM is going to be a problem. The “modern web” would bring those machines to their knees. Still, surprisingly modern.

Go back another 15 to January 1980 and you have to wait almost two years for hardware that will even run ELKS. Crazy.

Oh well... At least, in 1980 we got Xenix.

This is what I've been looking for! Can you fit a workable version on a 1.44 floppy?

Around 1996/97 timeframe, you could fit a kernel and userspace. I remember building a 1.44 setup that booted a compressed kernel and had enough user space tooling to bring up telnet, ftp, and the radio stack to drive the long haul radio cards (we were replacing JNOS [0] IIRC at an ISP ). Even had writable space at the end of the floppy (the kernel etc were readonly) to write overrides of the config; poor man's overlay I think, but it is rather a long time ago.

Given we were working with 286 era hardware (maybe 386?), I'd be surprised if ELKS doesn't fit on a 1.44. Indeed, simply looking at the downloads page linked from the original link would have answered your question.. [1]

0 - https://www.langelaar.net/jnos2/documents/about.html

1 - https://github.com/ghaerr/elks/releases

I'm totally going to run it on an Amstrad PPC640 soon :)))

Well, for that you need to fit it on a 720k floppy :) Unless you modded it with a 1.44 drive

Yes it runs on that Amstrad. A funny story about the Amstrad, at one point we added divide-by-zero trap handler in the kernel for user space apps. When the Amstrad reboots via our 'shutdown', its gets a div zero exception in its own BIOS (which at the time prohibited the reboot, lol).

I'm having a play on the PPC640 with a Gotek running Flashfloppy with fd720-fat.img

It's erroring after the mount with panic:No init or sh found SYSTEM HALTED. BOOT:

The computer is unreponsive at the boot: prompt.

I've tried a few different settings in the ff.cfg, but no joy. Could it be a Gotek issue?

Open up an issue on GitHub and we can help you better. The usual reason for problems like this is the layout of the image is incorrect on GoTek, and/or the GoTek is set to the wrong CHS (cylinders/head/sector) for the image being used.

Also worth trying would be the 1440k image, as that's the later standard 3.5" floppy format.

Single-floppy router distributions were also in style: https://en.wikipedia.org/wiki/Floppyfw

I'm 99% sure the original kernel and thus the boot&root disk Linux (the original "distribution" I guess) only ran on the 386 & up as it required & used the memory management capabilities.

There were some forks that could run without the mmu (micro-Linux I think?) but as I recall it they came quite a bit later.

Edit: Ah, close, this: https://en.m.wikipedia.org/wiki/%CE%9CClinux

We dropped all support for 286 or 386+ protected mode/paging etc, as well as produce only 8088/8086 instructions so it'll run on any x86 (including the PCjr with its peculiarities, remember that?) running in real mode only without MMU. Of course, that means any program can write anywhere, so more care is taken towards program correctness, which is kind of fun.

That's pretty cool about the radio stack!

We don't support a compressed kernel anymore but have a way to compress user executables which saves about 30%. Sadly, even with straightforward decompression, that process on ancient 8088's sometimes takes longer than reading an uncompressed executable. But we're finally at the point of having "too much stuff" to fit on a floppy. And of course everyone wants games. (Don't ask about Doom: yes we have it, no it doesn't fit on a floppy :)

Check NeHaBodi. Nethack 3.4.3 or Slashem 0.7f might compile under elks, slashem itself shouldn't need ncurses, but it would need some colour support to differentiate some mons (not as a requeriment, but it helps a lot on the gameplay).

Can you find a 1.44 floppy?

Yes, one can actually boot and run a minimal system on 360k floppy, but if you want networking you need 720k. The native compiler might fit on 1440k but needs a lot more for any development if the C library header files etc are wanted.

With so little context in your question I'll reply with

https://en.wikipedia.org/wiki/Linux_Router_Project

I remember using this in the late 90s (maybe early 2000s). A linux distro designed to be a router, and to fit on (and run from) a single floppy.

Could nethack be compiled under elks? Frotz? Inform6?

There was a DOS port of nethack, so likely it could be made to run on elks.

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