Show HN: GentleOS – A pair of hobby OSes for vintage 32-bit and 16-bit PCs

Posted by luke8086 2 days ago

Hello HN,

I've been working on a simple OS for tinkering and running bare metal apps on vintage PCs.

Since I couldn't quite decide whether to target pure 16-bit, or slightly more capable 32-bit machines, I ended up with two separate versions:

- GentleOS/32 (https://github.com/luke8086/gentleos32) works on i386+, requires 4MB of RAM and VGA display supporting 640x480x16 mode or any 256-color VESA mode.

- GentleOS/16 (https://github.com/luke8086/gentleos) works on 80186+, requires less than 192KB of RAM and a CGA display supporting 320x200x4 mode.

You can find more details in the repos.

Comments

Comment by mysterydip 12 hours ago

> The only future plans are bugfixes, optimizations, and adding more apps.

Perfect. Nice to see a platform target stability instead of constantly reinventing itself and its APIs. Definitely want to give it a go!

Comment by iamnothere 23 hours ago

This is great, thanks for releasing your work. Very impressive.

You may get some interest from others in the retrocomputing/permacomputing sphere if you implement an Uxn emulator; it is extremely simple and can run on very limited hardware. https://100r.co/site/uxn.html

Vintage hardware would be a great host for Uxn programs, so I suspect this would generate some excitement.

Comment by luke8086 6 hours ago

Thank you so much! Somehow I haven't heard about Uxn before, but it seems very cool and I'll definitely look into it.

Comment by iamnothere 5 hours ago

You’re welcome. You’d probably appreciate its focus on long-term stability; the authors wanted an environment for their software that would ensure code could stay frozen in a working state forever. The only thing that may need updates is the VM, as the host OS and userland will shift over time, but the VM is designed to be exceptionally easy to implement and maintain. That comes at the cost of some capabilities, but they were specifically aiming for simpler software, so it works out.

Comment by sandos 8 hours ago

Heh, the "small virtual machine" was NOT a lie! Is that less than 200 lines? Very nice!

Now I feel like integrating that into various things....

Comment by nosioptar 10 hours ago

I think this is fantastic! I love that the code is so clean my dumb ass can understand it despite not using C much.

Comment by sixothree 9 hours ago

The code is cleaner that what I was expecting from a C repo. Also, it's quite a feat to fit this into 4 MB on a 386.

Comment by lproven 7 hours ago

> it's quite a feat to fit this into 4 MB on a 386.

I had 2 different Librex 386SX laptops, with 4MB of RAM, on long-term loan from work around 1992. One was quite chunky, the 2nd was a slimline thing with an off-centre hinge.

I ran OS/2 2.0 on them both.

So I could run multiple DOS apps, and a WinOS2 VM containing Windows 3.0, meaning I could run Win16 apps as well. And native OS/2 apps, although I didn't have many.

Here's a pic of the original Librex:

https://books.google.im/books?id=tDwEAAAAMBAJ&pg=PA27&redir_...

And the 2nd model:

https://www.reddit.com/r/vintagecomputing/comments/10gepdd/l...

TL;DR

A 386 with 4MB is small now but at the time this was a fairly serious workstation-level PC. At the time my work desktop was a 386DX but it had only 1MB of RAM.

In its time a 4MB 386 could run any one of multiple multitasking 32-bit protected-mode OSes, including OS/2 2.x, SCO Xenix, Coherent 3 or 4, DR Concurrent DOS/386, and so on.

This was a high-end bit of kit and with one of these OSes, or even with Quarterdeck DESQview, it could multitask half a dozen large and demanding DOS apps, or maybe a couple of the still fairly new Windows apps such as WinWord 1, or Excel 2.

Comment by oso2k 6 minutes ago

I have one those Librex as well. It was fun to play with when it came into my hands back in 1997.

Comment by nosioptar 5 hours ago

That's a wonderful machine. I'd love to see that style of keyboard on new stuff.

Its wild to me to think of how much old computers could do relative to new. WordPerfect for DOS was always responsive and quick wheb I used it. I've seen ms word cludge up machines that should have plenty of power to run a word processor.

Comment by lproven 4 hours ago

> I'd love to see that style of keyboard on new stuff.

OMG yes please. :-)

Yep, WP for DOS was quick. Rather clunky UI compared to MS Word for DOS, IMHO, but fast. A friend of mine used a simple method to demo its speed: on his cheap monochrome 286 home computer, he loaded the book he was working on -- one big file, a few hundred pages -- and just held down the cursor key to scroll through the whole thing. It kept the entire doc in RAM and the text just blurred as it zoomed through the entire book in under a minute.

Compared then (early 1990s) to Windows where a similar text took tens of minutes, as my faster computer struggled to load in pages of text from disk, render the fonts, etc.

In the late 1980s, Amstrad introduced new CP/M machines, the PCW range:

https://www.cpcwiki.eu/index.php/PCW

They sold for over a decade and shifted about 8 million units. A CP/M computer, in the early Windows era.

Maybe it's time to do that again: a very low-spec machine, but with a crisp e-ink screen and a great premium-grade mechanical keyboard, shipping with a modern FOSS DOS, a compilation of free DOS apps, and some nice friendly graphical launcher. Wrapped up as an easy appliance that doesn't do Internet stuff at all, but makes it trivially easy to save your work on USB media or zap it to modern devices wirelessly.

Form factor of a big late-20th-century laptop, with a massive battery so it can double as a power bank for your phone or something.

Comment by NoGravitas 6 hours ago

I had a 386SX-16 running OS/2 from 2.1 to 3.0. It was usually fine, you could multitask several OS/2 and DOS applications or a WinOS2 session. It was very easy to get it swapping, though, and when it was swapping, it ground to a halt. It helped a lot putting 8MB on it, though 4 of those were on an ISA card and very slow.

Comment by lproven 4 hours ago

Reminds me of my early-1990s home network server: a late-1980s IBM PS/2 Model 80, a 386 tower built with a moulded iron case. Super tough, fancy 32-bit IBM expansion bus. 4MB of RAM on the motherboard, another 4MB in an expansion slot.

I attached a couple of big SCSI drives and ran Windows NT 3.51 Server on it. When not logged in, it only used a couple of megs of RAM for the OS so file serving performance was tolerable -- and the hardware was literally bulletproof. I dropped one down a flight of stairs in my first job. The computer survived but it knocked lumps out of the concrete stairs on the way down.

Comment by icedchai 6 hours ago

My first Linux box was a 386SX with 3 megs of RAM (1 meg on the motherboard plus a 2 meg expansion.) It was a tight fit (SLS Linux, I think?) This would've been around 1992 or 93.

Comment by sixothree 3 hours ago

For you to downvote my small comment, and then go on to lecture me about things you have barely any grasp or memory of, is just astounding to me. I currently own at least 5 computers with 4 MB of RAM, part of a collection of computers that is too large to count (hence the project on github).

A 386 with 4MB was the bare minimum to run Windows 3.11, which is considered the first mainstream GUI for PCs. Technically they required 3 MB, but recommended 4 MB.

Topping it all off, you're being disingenuous by suggesting running OS/2 desktop applications with just 4 MB of RAM. OS/2 was _notoriously_ memory hungry. At the very least it required more RAM than Win 3.11 (which recommended 4 MB). While OS/2 required 4 MB, suggested 8 MB as a minimum, but really needed 16 MB to do anything remotely useful.

And for you to not remember that is pretty telling.

Comment by Waterluvian 7 hours ago

Kind of an odd statement I think, but I really like the aesthetic of early OS GUIs where you could tell half the tools were pretty much there as developer tools.

Comment by ajxs 1 hour ago

Really awesome work! A simple OS for retro x86 hardware is a really cool project! I wish I still had some era-appropriate hardware I could test-drive it on.

Comment by Aldipower 12 hours ago

A pre-build floppy disk image would be great, so I could run it on my IBM PS/1 from a floppy.

Comment by Aldipower 10 hours ago

Ok, I built the floppy image now. dd'ed it on a floppy and powered my IBM PS/1 up. Despite some nasty sounds of the HDD bearings that went away after 30 seconds, the floppy does not boot on this machine. Just a black screen. 386SX-25 2MB RAM. Maybe 2MB RAM too less, but I thought at least something will happen. :-)

Comment by luke8086 6 hours ago

Even on 2MB, you should be able to at least see GRUB, which would tell you that it can't load the kernel. Does it go blank before that? This could mean an issue with either GRUB or the floppy.

Comment by Aldipower 2 hours ago

Yes, it goes blank before GRUB and after 2MB count-up. I ruled out a defective floppy too. I suspect GRUB?

Comment by luke8086 1 hour ago

Yep, possibly.

In case you have DOS installed on the hard drive, you can also use GRUB4DOS [1] - just put gentleos.elf on C:\, run grub.exe, then `kernel /gentleos.elf`. You may first need to comment out any upper memory managers from config.sys. A bit of an academic exercise since the kernel still won't fit into memory.

Btw. feel free to reach out to me on my profile email. I'll be busy with work for the rest of the week, but later I may look for some workarounds to get it running on 2 megs.

[1] https://sourceforge.net/projects/grub4dos/

Comment by valleyer 12 hours ago

There seems to be an 8 meg image here: https://github.com/luke8086/gentleos32/releases/download/202...

Comment by ginko 12 hours ago

Someone prepare a set of floppy disk images so you can get the proper installation experience.

Comment by RobotToaster 10 hours ago

Including the mandatory corruption on the last one.

Comment by Aldipower 11 hours ago

This is a hdd image, I guess.

Comment by sillywalk 6 hours ago

I'm curious what model of PS/1? My first PC was a PS/1 model 2011, with a 286@10Mhz.

Also, there's an emulator for PS/1 machines at https://www.ibmulator.org/

Comment by luke8086 10 hours ago

For PS/1 you'll need the 16-bit version from https://github.com/luke8086/gentleos. A floppy image is provided in releases. Note you only need to copy the first 64KB, the rest is just padding for emulators.

Comment by Aldipower 8 hours ago

Ah, even though the 386SX-25 is 32bit in my PS/1? Will try it eventually.

Comment by luke8086 5 hours ago

Oh sorry, a quick google check told me PS/1 had 286. 386SX itself should be supported, the monochrome Toshiba on the photo has 386SX/20 with 10MB RAM.

Comment by Aldipower 3 hours ago

Anyway, I tried the 16bit version, and it works like a charm!! Thank you. Here's a video of the boot, I've just made. https://www.youtube.com/watch?v=1fSsTa8Oc48

Although, the floppy light does not turn off. Not sure, if this a problem with the OS or my hardware.

Comment by gunapologist99 7 hours ago

Yes, the CPU is full 32-bits, but the bus in a 386 SX is only 16 bit. Those PS/1's are such a cool piece of computing history!

https://en.wikipedia.org/wiki/I386#80386SX

Comment by wtallis 6 hours ago

The data bus was only 16 bits wide, but that doesn't really have much impact on OS compatibility; it just means that transferring a 32-bit value to or from memory takes two bus clock cycles instead of one. The address bus is only 24 bits wide, but that only affects physical memory address space; it still uses 32-bit pointers and a 32-bit virtual address space.

Comment by hansvs 10 hours ago

Nice! The project also has a 16-bit variant https://github.com/luke8086/gentleos, not clear if it works on 8086 IBM PC, but I'll give it a go. Been looking for a reason to power up my IBM PC again.

Comment by reconnecting 12 hours ago

GUI looks a but BeOS inspired, but somehow even cleaner.

Comment by luke8086 10 hours ago

Good catch, the yellow and blue colors are totally inspired by BeOS :D I'm even adjusting the default VGA palette to get the right tints in 16-color mode.

Comment by tecleandor 11 hours ago

I think it's that yellow bar what it makes it look like BeOS. And maybe the right hand menu bar. But once you check a B/W version, it doesn't look like BeOS that much.

Comment by MisterTea 10 hours ago

More like a Win 3.1 theme with BeOS colors and a NeXT desktop.

Comment by gt0 11 hours ago

Made me think of Breadbox Ensemble, which is GEOS, and was really lovely.

Comment by lproven 7 hours ago

FWIW, still around and now FOSS.

https://github.com/bluewaysw/pcgeos

Comment by j1greene 3 hours ago

Does this OS (either the 16 bit or 32 bit version) require apps built for it, or is it compatible with DOS or Windows 3.x or any other OS.

Comment by amelius 10 hours ago

Part of why these images look so nice is because these systems were not so locked down.

Comment by aktau 4 hours ago

I clicked around in the kernel section and the other commenters highlighting the simplicity weren't lying. It's beautiful in its simplicity.

Seeing the screenshots I was kind of expecting this was a pre-emptive multi-tasking OS (forgetting what I read in the submission).

Things that thus surprised me on a cursory look:

  - noticed krn_main() ends with `while (1);` [1]. I would've expected a "schedule" call or something. I assume there's no real busy loop burning CPU, maybe it's never meant to reach this code?
  - I'm reminded of the "bare metal OS" when I see one of the apps call `krn_\*` functions directly [2].

[1]: https://github.com/luke8086/gentleos32/blob/main/kernel/main...

[2]: https://github.com/luke8086/gentleos32/blob/ea691f14635c023d...

Comment by luke8086 2 hours ago

Thanks, so glad people like the code! I keep looking for ways to make it simpler and more obvious.

> - noticed krn_main() ends with `while (1);` [1]. I would've expected a "schedule" call or something. I assume there's no real busy loop burning CPU, maybe it's never meant to reach this code?

Yeah, `gui_main()` takes over and is not supposed to return, so the code is unreachable. The loop is just an old idiom used in such places (e.g. [1]), though I've now replaced it with a comment and a call to `halt()` to better convey the intention.

> - I'm reminded of the "bare metal OS" when I see one of the apps call `krn_*` functions directly [2].

Yeah... but at least the kernel doesn't call the apps... which it could ;^)

[1] https://github.com/freebsd/freebsd-src/blob/main/sys/x86/x86...

Comment by Dwedit 7 hours ago

There weren't too many GUIs that used the PC-BIOS font. Most of them wanted to get away from that.

Comment by ge96 8 hours ago

Ahh the Librettos... I had a couple of 50s at one point, one of those looks cool unusable thing and the brittle plastic damn, I opened it and the hinge snapped lmao my heart my soul

Unusuable because of how small the keys are

Comment by rasz 8 hours ago

Am I crazy or are the "photos" generated? I did have T1800 and it never looked like this. It had a very early very bad grayscale LCD wiht fiddly contrast control, not a perfect crisp vibrant OLED like this page shows.

example how one looks like irl https://allegrolokalnie.pl/oferta/laptop-toshiba-t1800 https://www.youtube.com/watch?v=sxIc_UVKxvc

Comment by luke8086 4 hours ago

All the photos are real, though it took me *lots* of time to get them somewhat right. The display on T1800 is indeed "challenging". What helped was:

- Letting it warm for a while

- Putting windows in the right places, because each one generates its own artifacts

- Setting background to dark with the white pattern

- Fiddling with the contrast knob and matching it with the right viewing angle

- Using 2x zoom

To be fair, the default photo app of iPhone 16 automatically reduced some of the artifacts. The only post-processing done myself in GIMP was very basic stuff like adjusting white balance, exposure and contrast.

Here you can see a few very quick-n-dirty photos I just took for comparison - https://imgur.com/a/6Xz6vc8

Comment by bor_real 6 hours ago

Perhaps a new panel was retrofitted into it?

Comment by rasz 6 hours ago

OLED panel? that would be a bigger hack than this OS :) Either all pictures are AI generated using QEMU templates that were there previously https://github.com/luke8086/gentleos32/commit/d40576226b7020... or those are real pictured beautified by AI. YT loves doing that to thumbnails, example https://hackaday.com/2026/06/03/hydraulic-drive-for-your-law...

Comment by luke8086 4 hours ago

The only AI-generated artifact is the cyberpunk wallpaper from the last photo, I'll admit that :)

Btw. the QEMU screenshots are still in the repo in https://github.com/luke8086/gentleos32/tree/main/doc/appimg

Comment by phendrenad2 8 hours ago

Love the photos of it running on 386/486 laptops. So cute!

Comment by vortegne 9 hours ago

What a lovely-looking OS! Also great to hear that the project isn't aiming for infinite changes!

Will be digging out some old hardware to test it out very soon, this is exciting!

Comment by Damjanski 10 hours ago

<3<3<3

Comment by mohammad_dev 2 days ago

[flagged]

Comment by mdct 11 hours ago

This reminds me of the era when operating systems felt more approachable and visually distinct. Modern UIs are often cleaner, but many of them have lost some of the personality that older systems had.

Comment by kolesnikov-arch 11 hours ago

[dead]

Comment by xtiansimon 11 hours ago

[flagged]

Comment by nosioptar 11 hours ago

That video's bullshit. People prefer old UIs because modern ui is shit, not because they're not creative.

Computer programs are tools. It doesnt do anyone any good if they're unusable in the name of chasing moronic trends.

Comment by reconnecting 10 hours ago

I have a theory that corporations make new UIs to entertain people through them. First, to create the feeling that something is happening, and second, to increase screen time.

Old interfaces were far more practical for getting work done, and therefore obviously boring.

For me, as someone who is supposed to use technology as a tool and not as a source of amusement, the new interfaces of the major OSes feel unacceptable. But the other billion people chatting and scrolling are the real consumers, not me — and as a result, we now have the interfaces we have.

Comment by latexr 7 hours ago

That’s one reason corporations make new UIs, yes, but the other is users demanding them for the sake of novelty. Reddit (but not only) is filled with people with no design sense complaining about how something which works (because it was relentlessly iterated on) looks “stale” and “old”. They’re the same users who jump from app to app willy nilly just chasing novelty. Any turd, if hyped enough, is ailed as “the future”, “modern”, “innovative”, which is repeated drivel from what the corporations tell you when they introduce their next thing.

Comment by alterom 9 hours ago

Not really a theory.

Software makers treat UIs the way auto makers treat paint and body styling.

Comment by luciferin 9 hours ago

I think there's a couple of different forces at play in the convergence of GUI design that we're seeing in the past 20 years. First, there's been a huge amount of widely accepted research that shows what the most accessible way to design an interface is. Things like Google's Material Design and Apples Human Interface Guidelines come to mind. Second, the widespread availability of those two specific design guides make it increasingly common for developers to just create to those. It ensures that things just work and are increasingly portable. Third, we're in a landscape where API stability and design is prized. That's partially because of the number of times that design has been broken by updates and version changes. It takes many years for developers to update their applications when a new back-end is developed, and the time in between gives broken applications, and ugly looking fallback. You can look at running GTK1 apps on modern GNOME, or X11 apps rendering on Wayland over the past decade for an example of this.

All that said, I truly miss the days when we had interface skinning. There was a skin for OS X called UNO that was absolute perfection in my eyes, and it was ported to an old version of Android back when skinning was a thing. There's nothing like it available now. Even GNOME is highly against theming and skinning now, apparently because they like breaking with every single release rather than maintaining an API/ABI and skinning support. The themes that were available for Windows XP were so much fun, even if you had to swap out DLLs to get them working.

Comment by zozbot234 9 hours ago

> First, there's been a huge amount of widely accepted research that shows what the most accessible way to design an interface is.

Focus-group based and UX research was a lot more intense in the 1990s compared to today, and late 1990s UIs are still among the best available.

Comment by nosioptar 8 hours ago

Google's Material Design is fucking awful from an accessibility standpoint. There's no contrast. Clickable items don't look clickable. With a keyboard/remote, you can never tell what's selected.

Material is what made me hate google. It makes everything so difficult. It doesnt even look good. It's a low contrast sea of modern bullshit.

I sincerely hope that the material designers go to hell when they die and are forced to use their own garbage designs for all eternity while those of us who dont suck can use properly designed software.

Comment by mftb 7 hours ago

I generally agree with you about UIs (if by shit you mean they've thrown away a ton of utility), but I don't think his video was bs, maybe just moved too far from it's original context.

Comment by LastTrain 10 hours ago

Like almost all bullshit that is believable by a multitude, it is couched in some very small truths.

Comment by Aldipower 11 hours ago

So, you poop everywhere you go. Interesting.

Comment by dang 7 hours ago

Please don't do this here.

Comment by darkwater 11 hours ago

I don't really understand GP's message. User's comment history seems pretty normal, why would they drop a random IG link here? Wrong article?

Comment by LastTrain 11 hours ago

The link is to a designer talking about how technology has led us to a design world that is mostly driven by nostalgia. I personally don’t see it as being applicable here as it deals with big design houses not hobbies, but I can see why someone might think it is.

Comment by cestith 9 hours ago

What a designer might call nostalgia an actual user of an OS might call standard, or maybe even intuitive. The point of an operating system is to be used. If it’s pretty, that’s a bonus. Usability by the target audience is the primary concern.

Comment by nosioptar 10 hours ago

To anyone interested in the video, but without an Instagram account, gramsnap sometimes works. (Imginn.com sometimes works for viewing IG profiles.)

https://gramsnap.com/en/instagram-reels-viewer/

Comment by LastTrain 10 hours ago

The video is a word salad of self-aggrandizement and judgement. Don't bother. The dude holds up fashion as if it is some paragon of virtue.

Comment by nosioptar 9 hours ago

The first sentence of your comment seems to describe 99% of social media.

Comment by neofrog 10 hours ago

[flagged]

Comment by linkdd 8 hours ago

[flagged]

Comment by shevy-java 11 hours ago

> A hobby operating system for vintage 32-bit PCs.

I am all in favour of great projects, but why a differentiation between 32-bits or 64-bits? I don't understand that. Is a computer that is 32 bit or 64 bit, either way which, not worthy?

Edit: I understand a motivation if it is on simplicity choosing one or the other, but other than that I don't see why that should ever be a goal worthy to be pursued. Software should really "just work" no matter the number of bits and bytes.

Comment by luke8086 10 hours ago

In this context, 32-bit means the minimal requirement. You can absolutely run even the 16-bit version on a 64-bit PC, provided it has BIOS/legacy-boot mode.

It only won't work on modern pure-UEFI systems because that would require writing full stack of USB drivers for keyboard and mouse, and that would be a huge task.

Comment by grebc 11 hours ago

“Vintage” 64 bit PC’s aren’t a thing.

> Edit: I understand a motivation if it is on simplicity choosing one or the other, but other than that I don't see why that should ever be a goal worthy to be pursued. Software should really "just work" no matter the number of bits and bytes.

Not really how software works.

Comment by Aldipower 11 hours ago

> “Vintage” 64 bit PC’s aren’t a thing.

Just sold my SGI Indigo 2 for 900 $ ! Vintage 64 bit is absolutely a thing. :-)

Comment by amuradbegovic 11 hours ago

they said PCs

Comment by trashb 10 hours ago

The DEC 3000 would like to have a word with you.

Comment by nocman 8 hours ago

Yeah, DEC Alpha was the first thing to come to my mind. I guess some might argue it wasn't a "PC" - if you don't include what used to be called "workstations". This is largely because PC meant "personal computer", and very few people could afford their own DEC Alpha - they were very pricey ($20k at some point in the 90's, I believe).

Comment by Aldipower 10 hours ago

It even has 64 bit "word" size!

Comment by RobotToaster 10 hours ago

Itanium was released 25 years ago now...

Comment by hnlmorg 10 hours ago

Whilst that’s definitely old in computer terms, even “retro”, is it old enough to be “vintage”?

Personally I’d have said it isn’t. But these terms are subjective.

Comment by rob74 9 hours ago

"Vintage" usually refers to actually old stuff, while "retro" refers to new stuff that looks/sounds/feels like old stuff. So GentleOS is a retro OS designed to run on vintage hardware.

(That distinction wasn't clear to me either, so I had to look it up - TIL).

Comment by pjc50 11 hours ago

Don't worry, this is portable to both vintage word sizes: 32 and 16.

Comment by trashb 10 hours ago

x86 boots in 16-bit real mode. Then you need to specifically transition into 32-Bit, and from 32-Bit it can be transitioned to 64-Bit Architecture...

The last step (32-bit to 64-bit) can a bit of a can of worms especially on older platforms where 64-bit implementations can differ greatly and 32-bit "just works tm". 32-bit is quite well supported and has enough resources to make some interesting programs work without much hassle.

I think the author has made the decision not to support 64-bit mode due to needing to balance the complexity and usability of the project. It is a hobby project after all.

Since the author maintains a 16-bit and 32-bit for this project I suppose if you wanted you can always fork and maintain a 64-bit version if you wanted to.

Comment by 9 hours ago

Comment by ReptileMan 11 hours ago

32 is vintager vintage

Comment by Aldipower 11 hours ago

32 bit vinteger ;-)

Comment by bayindirh 11 hours ago

You can do 32 bit voolean too, great for that vintage bitmasks to store application flags. =]