questions
copperos.iso
1.8 MB. Start here. Boots in QEMU and in VirtualBox's optical drive.
What is CopperOS?
A small experimental operating system for 32-bit x86, written from scratch for learning and for boot demos. A NASM boot sector loads a freestanding C kernel, the kernel brings up a VESA graphics mode, and it draws its own desktop with eight built-in apps. The finished system is about 1.8 MB. Longer answer here.
How do I try it?
Download the ISO and boot it in a virtual machine — that is the tested path and it takes one command:
qemu-system-x86_64 -cdrom copperos.iso -m 256M -boot dVirtualBox works too: type Other / Unknown (32-bit), 256 MB of RAM, and EFI switched off. The download page has every setting written out.
Why does the Try it page say OUT OF ORDER?
The in-browser emulator is switched off. It was not CopperOS failing — it was the emulator hosting it, which depended on an outside CDN, downloaded the whole ISO before showing anything, and only approximated the BIOS calls Copperhead relies on. Rather than leave a page that hangs on "Booting…" with no explanation, it now says what is true. The whole story.
My download came out as an HTML file. What happened?
That was a real bug on this site, and it is fixed. Missing files used to redirect to a valid web page, and your browser dutifully saved that page under the name you asked for. The release binaries are now published properly, they are served with the right content type, and a missing file now returns a genuine 404 instead of a page. How to check the copy you already have.
Which file should I take?
copperos.vdi
1.0 MB. Attach as a VirtualBox hard disk instead of a CD.
copperos.img
1.4 MB. A raw sector image, for -drive format=raw or a hex editor.
Every one of them has a line in SHA256SUMS. Checking it takes ten seconds and rules out the single most common cause of a machine that will not boot.
Is it safe for production?
No, and it is not close. There is no process isolation, no filesystem worth the name, no networking, and no security model. Run it in a virtual machine. Putting it on hardware you care about would be a mistake that is entirely yours to make.
What are the cookies for?
Keeping you signed in to Discussions, remembering the answer you gave the cookie notice, and protecting the admin area. Two optional categories — small interface preferences and a count of which pages produce errors — are yours to refuse, and refusing costs you nothing but convenience. No advertising, no third-party trackers, nothing sold or shared. Every cookie is listed here, and you can change your answer on that page at any time.
How do I report a problem or send feedback?
The support page reaches the CopperOS team by email. What helps most is boring detail: which host, which virtual machine, what you did, what you expected, and what happened instead. Reports written that way are how new entries end up on the Why did this happen? page.