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siraben
zkeme80
Scheme2019–2026
siraben / zkeme80

zkeme80

An assembler and operating system for the TI-84+ written in Scheme, Forth and Z80 assembly.

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Explore on GitHubRead Hacker News discussions
4Distinct people
12Mentions
0Explicit recommenders
257GitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

An assembler and operating system for the TI-84+ written in Scheme, Forth and Z80 assembly.

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

Mentioned in the same Hacker News threads. That is not proof they are substitutes.

This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 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 year12 dated mentions

Observed mentions: 2019-01-04 23:03:52 UTC to 2026-07-17 22:12:26 UTC.

0123452019-01-01 00:00:00 UTC to 2020-01-01 00:00:00 UTC (exclusive): 5 mentions; 3 submissions, 2 comments20192020-01-01 00:00:00 UTC to 2021-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments2021-01-01 00:00:00 UTC to 2022-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 3 mentions; 0 submissions, 3 comments20222023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2026-01-01 00:00:00 UTC to 2027-01-01 00:00:00 UTC (exclusive): 1 mentions; 0 submissions, 1 comments. Incomplete calendar period.2026*

* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.

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

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20192019-01-01 00:00:00 UTC2020-01-01 00:00:00 UTC532
20202020-01-01 00:00:00 UTC2021-01-01 00:00:00 UTC303
20212021-01-01 00:00:00 UTC2022-01-01 00:00:00 UTC000
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC303
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC000
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC000
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC000
2026 (partial)2026-01-01 00:00:00 UTC2027-01-01 00:00:00 UTC101

What Hacker News says

12 sources
siraben·Jul 31, 2022
I've owned a TI-84+ calculator since around middle school (they are priced ridiculously everywhere on the planet, and this only exacerbates the problem because of purchasing power differences). However, it can provide a unique programming environment that rivals modern setups with a lot of learning potential (perhaps I would recommend NumWorks these days, but it's still $100.) One of the earliest programs I wrote in middle school was a program to solve quadratic equations given the coefficients, then a program to compute the golden ratio by iterating the function f(x) = 1+1/x, and a Langston's ant program (all written in TI-BASIC on the device itself, with zero setup necessary.) Later on in high school (late 2010s) as I learned C programming and data structures on my own, I read "Learn TI-83 Plus Assembly In 28 Days"[0] and got into asse
Read the rest
mbly programming, eventually culminating in a Forth-based operating system[1] that runs from boot. You do need to have a computer for this setup, but the calculator comes with a cable in the box. It also was not uncommon to see other high school students download games or do light forms of hacking (mostly centered around storing data to be retrieved during exams.) Contrast this to if you wanted to do assembly programming on a modern computer and understand the boot processes of your machine. It's significantly more complicated that even at the university level it is not taught in detail. The boot process[2] or memory mapping[3] for the 84+ can be understood relatively easily, and the assembly instructions are much simpler. While I similarly lament the price point, the fact that you have essentially given/required the purchase of a standardized, self-contained, non-trivial computer to students could potentially be used to teach programming and computer science from an early age. [0] https://tutorials.eeems.ca/ASMin28Days/lesson/toc.html [1] https://github.com/siraben/zkeme80 [2] https://wikiti.brandonw.net/index.php?title=83Plus:State_of_... [3] https://wikiti.brandonw.net/index.php?title=83Plus:Memory_Ma...
In TI-83 Plus One More
siraben·Jul 30, 2020
Seeing projects like this from time to time always brings renewed interest to the TI graphic calculators. A while back I wrote a Forth-based operating system for the TI-84+[0] which uses the TiLem emulator[1]. I didn't want the software to bit-rot as well, so having a Nix build file would ensure the OS and emulator stay working into the future. [0] http://github.com/siraben/zkeme80 [1] http://lpg.ticalc.org/prj_tilem/
In Tihle: A new emulator targeting TI graphing calculators
siraben·Jul 12, 2020
This nicely provides empircal evidence on the slowdown of using Forth, which seems to be around 10 to 20 times slower than optimized assembly. I was initially surprised by how poorly Forth performed on all counts of speed, memory usage and development time. For something as complex as a game the lack of a type system and postfix nature make Forth quite unsuitable. When I use Forth, it's often for high-level applications[0] with the performance critical words written in assembly. So this keeps the complexity relatively low as opposed to writing the whole thing in Forth. [0] https://github.com/siraben/zkeme80/blob/master/src/bootstrap...
In Robot Game: Comparing 6502 C, Assembly, and Forth
siraben·Nov 26, 2019
As someone who has just got out of the curriculum that enforces usage of the TI calculators, given the ubiquity of these devices, I wish it was used more in teaching students about low-level programming, hardware, etc. especially with older models such as the TI-84+ there's great hacking potential. Compared to programming on the modern software stack, the Z80 is minimal. Plus, who said it has to be in assembly? Forth would do! Some of my own hacking attempts: [1] https://github.com/siraben/zkeme80/ [2] https://github.com/siraben/ti84-forth/
In Big Calculator: How Texas Instruments Monopolized Math Class
DogestFogey·Jan 15, 2019Submission

Show HN: I made a Forth-Based OS for the TI-84+ Calculator

https://github.com/siraben/zkeme80 As a successor to my previous project[1], a Forth interpreter that runs under the TI operating system, I decided to go all the way and write my own assembler and OS. This is a project I've been working on for just over a month, but there's still a long way to go. The idea is to have a kernel + the Forth interpreter and compiler, then users can modify how their operating system works through the Forth files. My Forth implementation is mostly ANS-standard conforming, so most code should work right out of the box without any problem. See the GitHub repository for more, along with building instructions (you only need Guile and make build!) [1] http://github.com/siraben/ti84-forth
6 points · Open discussion

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