Small Linux distros (one is 1.44MB)

[Caldor]

I have been looking into some very small Linux distros and wanted to try them on the MiSTer and its AO486 core.

One is Kolibri OS, which can run from a 1.44MB floppy and somehow still have a web browser, file manager, Minesweeper, Snake, Flappy bird, a text editor, calulator and more. But the one hardware requirement that stops it from running on AO486 is that it needs a Pentium CPU.
https://www.youtube.com/watch?v=SATYQyIcimM&t=607s

Another OS I looked into was Damn Small Linux, it can boot from a 40MB bootable CD. It is actually made to run even on an 486 PC, but... it requires FPU.
https://www.youtube.com/watch?v=st-8V4MH3KA

Both of these OSes do boot on AO486, but Kolibri OS stops when trying to detect the CPU speed and Damn Small Linux stops when it finds that the CPU lacks a math coprocessor. Especially Damn Small Linux would most certainly be able to run if only we had FPU on this core. This seems like the a pretty good argument for trying to add FPU to this core. Until now it seemed like there was nothing especially useful you could do with FPU on this core because most things that really needed FPU would still not really work because the CPU and system overall would still be too slow.

[Caldor]

Since we are probably not going to get FPU anytime soon, other than software FPU, are there maybe any small Linux distros that can run on AO486?

[cursedverses]

Not quite what you're expecting, but apparently Slackware still hosts old versions that support 486SX (https://www.linuxquestions.org/question ... ost3571708)
A Slackware mirror seems to exist at https://mirrors.slackware.com/slackware/slackware-8.1/

I don't know how far you'll get with the IDE side of things - I'm not sure if the core was fixed for issues with Windows outside of a file rename so YMMV.

Godspeed in your endeavour, and let us know how you get on!

EDIT: I just remembered QNX did a 1.44MB demo disk years ago, around the time the Amiga looked set to use it.

[Krypto]

Kolibri OS isn't Linux based at all. An entire GUI distro written in assembly is awesome, however.

I believe the kernel itself still supports the needed FPU emulation, but it's doubtful you will find a modern Linux distro that still compiles the rest of the software to work on a 486SX. Nobody is going to QC software for hardware that no one will ever use.

One thing that should probably work is this:

https://web.archive.org/web/20050205085 ... ms.net/rb/

I used this a ton back in the day. It's a command line recovery floppy disk, however, no bullshit here.

From this thread, Knoppix would boot on a 386sx about twenty years ago:

https://debian-knoppix.linuxtag.narkive ... r-hardware

So you might want to find an Knoppix CD image from that time frame.

[klappschlauch]

I just tested slackware 12 on the latest ao486 core with kernel-2.6.21, and it booted fine into a shell.

[Bas]

What kind of disk controller does that distro see from inside ao486?

[thera34]

Since we are probably not going to get FPU anytime soon, other than software FPU, are there maybe any small Linux distros that can run on AO486?

Basic Linux: https://distro.ibiblio.org/baslinux/

I managed to create a VHD with it under 86box, until I realized there is a ready-made one under "BL 3.50 image for QEMU users" https://distro.ibiblio.org/baslinux/bl3-5qem.zip link on that page
Rename the .img to .vhd and it will work just fine under ao486. Still working my out with ppp and X graphical system.

[Stinky]

I used to run Debian 1.3 on a 386sx20 with 10mb RAM, then Debian 2.0 on a 486DX66 with 24MB. Old openbsd versions could also work I ran 2.6 on a 486.

[thera34]

I used to run Debian 1.3 on a 386sx20 with 10mb RAM, then Debian 2.0 on a 486DX66 with 24MB. Old openbsd versions could also work I ran 2.6 on a 486.

DX in the 486 CPU names meant they had FPU integrated.

Unfortunately ao486 lacks that so any Unix or Linux - based OSes must have their kernels compiled to use own 387 FPU software emulator for the systems which lacked it.
The micro-kernel Unix-like ELKS/Minix is an exception, as it will run happily on XT core as well and doesn't need FPU in any form.
Another major issue seems to be in the FDC and IDE controller, most Unix (starting from System V), continuing to BSD and Linux - like OSes will fail with different errors.

The only Unix and Linux (sry @Caldor for derailing your topic) OSes that I know are running on ao486 are:
-ELKS/Minix - works as well on XT core, supports serial and SLIP connectivity
-QNX 4.25 - works fine, supports PPP. Also its famous demo floppy disk works
-Gentoo Linux (5.15.11 kernel iirc) - not my work, still need to install at some point net-dialup so it would have PPP, already compiled the kernel to support it. Most modern Linux that I know to work on ao486
-Basic Linux 3.5 - Slackware 4 distro (2.2.6 kernel), still working to get a fully bootable bigger vhd and some better libs/browser/apps/SSL shenanigans, PPP working (as well as some libc5 compiled add-ons like mc, naim, icewm etc, hence the need to update libs)
-PicoBSD floppy - some old BSD crammed into a floppy image, more like a novelty, iirc it doesn't see/work with hdd images