KnightOS

kernel

Assembly2014–2018

KnightOS / kernel

kernel

Kernel for z80 calculators

Systems & Infrastructure

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3Distinct people

9Mentions

0Explicit recommenders

300GitHub stars

REPOSITORY AT A GLANCE

What to know before exploring

What it is

Kernel for z80 calculators

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

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Also in these discussions

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This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 12:54:37 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year9 dated mentions

Observed mentions: 2014-01-20 08:48:57 UTC to 2018-02-02 20:27:01 UTC.

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges

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Period	Start (UTC)	End (exclusive, UTC)	Mentions	Submissions	Comments
2014	2014-01-01 00:00:00 UTC	2015-01-01 00:00:00 UTC	4	1	3
2015	2015-01-01 00:00:00 UTC	2016-01-01 00:00:00 UTC	2	0	2
2016	2016-01-01 00:00:00 UTC	2017-01-01 00:00:00 UTC	0	0	0
2017	2017-01-01 00:00:00 UTC	2018-01-01 00:00:00 UTC	1	1	0
2018	2018-01-01 00:00:00 UTC	2019-01-01 00:00:00 UTC	2	0	2

What Hacker News says

9 sources

Sir_Cmpwn·Feb 2, 2018

Writing a microkernel in C is fine. I said _C++_. But for the record, I built this: https://github.com/KnightOS/kernel And I've worked on toy kernels here and there and studied more serious kernels in depth.

In Google’s Fuchsia OS on the Pixelbook

Sir_Cmpwn·Jan 6, 2018

For fun, I took a "happy medium" approach in KnightOS. Programs are written with RSTs (basically the z80 version of traps) next to each instruction with a relative address, then the kernel looks up the return address on the stack, partially decodes the next instruction, and then modifies the code in RAM to update the address to the correct one. It's basically just-in-time PIC. https://github.com/KnightOS/kernel/blob/master/src/00/restar...

In SymbOS: Graphical Z80 Multitasking Operating System

MaxLeiter·Oct 13, 2017Submission

KnightOS, an open-source operating system for TI calculators

3 points · Open discussion

Sir_Cmpwn·Oct 27, 2015

I worked with a friend of mine to write a documentation generator for assembly code. It lets you write your docs with markdown, and has "[[syscall]]" syntax to link to another syscall from your docs. Example: http://www.knightos.org/documentation/reference/threading.ht... https://github.com/KnightOS/kernel/blob/06aeba5442a073d02338...

In Classeur.io: Re-enjoy writing, with Markdown

Sir_Cmpwn·Jul 25, 2015

I'd be happy to give some more detailed thoughts. I write a lot of assembly myself [1], so hopefully that lends me some credibility. I haven't read much of your TLS implementation, but I'm not a security researcher and I don't think I'm qualified to give an opinion on your particular implementation. However, there are some points to be made here. First of all, almost no one ships their own crypto for a good reason. To trust that something is secure, you need to have lots of people working on it and lots of projects invested in it (something that OpenSSL and such have). "Many eyes makes bugs shallow" is the common phrase, but it holds truer when large companies with highly skilled engineers are putting their secrets and their customer's secrets on the line. Your implementation has the unfortunate problem of being written in assembly. While

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I don't think there's anything inherently wrong with assembly, many people don't share the same opinion. People will be reluctant to contribute to it (how do people contribute, anyway?). Also, it is easier to make mistakes in assembly, and I would be surprised if there weren't several mistakes in your TLS implementation and in the rest of the server. This doesn't reflect poorly on you as a developer, but is instead a consequence of choosing assembly. Assembly also inherits a lot of the common security problems C has (like buffer overflows), but makes them harder to identify. I would feel very uncomfortable exposing anything written in assembly to the public net, and doubly so if it used an unproven TLS stack written in the same. Other projects avoid the problem of untested crypto by using tested crypto from an external module like OpenSSL. [1] https://github.com/KnightOS/kernel

In Rwasa – A high-performance web server in x86_64 assembly

Sir_Cmpwn·Jun 16, 2014

> This is a complete replacement though, right? Yep. > IIRC, the firmware updates had to be signed, how did you get around that? Here are Texas Instrument's private keys: https://github.com/KnightOS/kernel/tree/master/keys

In KnightOS, a third party OS for TI z80 calculators

Sir_Cmpwn·Apr 7, 2014

I'm _still_ writing z80 assembly for those calcs! Want to help? https://github.com/KnightOS/kernel How about a kernel with preemptive multitasking, dynamic memory management, a tree-based filesystem, cross-platform binaries, and the comforts of Unix?

In Poll: How long have you been programming?

ddevault·Mar 8, 2014Submission

Show HN: I built an open-source kernel for Texas Instruments calculators

You know that old TI calculator you used in high school, then put in a box and forgot about? Have you ever wished you had an operating system for your calculator with preemptive multitasking, dynamic memory management, a tree filesystem conforming to the FHS, and all the comforts of Unix? Well, good news: that's totally a thing that exists. I've been working on my kernel for about three and a half years now and I'm looking for new contributors to help out. It's written entirely in z80 assembly, and it's both challenging and fun to work on. There's an IRC channel for contributors or people who are just generally interested. You should stop by! It's #knightos on irc.freenode.net. https://github.com/KnightOS/kernel

20 points · Open discussion

Sir_Cmpwn·Jan 20, 2014

This may not be entirely related, but I've been building an open-source kernel in z80 assembly for three and a half years now: https://github.com/KnightOS/kernel I might chime in with a perspective of someone working on 70s hardware without memory protection, ring modes, or enough RAM to page it around. In my system, all processes run as root (since we can't stop them from doing so on a z80), and share one big memory block. The kernel takes up the first 0x500 bytes of memory (which can be changed at kernel compile time), and the remaining 0x7A00 bytes of memory is distributed among the "userspace". Programs allocate memory here in a first-come, first-serve basis, and their own program memory, stack, and allocated space are all thrown together in this big userland memory space. Not sure if that's a valuable perspective, but thought you mig

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ht find it interesting. Here's some links: https://github.com/KnightOS/kernel/blob/master/docs/memory.m... https://github.com/KnightOS/kernel/blob/master/src/00/memory...

In Anatomy of a Program in Memory