What Can We Learn From Running Doom on A Calculator?

Video Description

This video was sponsored by Brilliant. To try everything Brilliant has to offer—free—for a full 30 days, visit https://brilliant.org/Tariq10x/ . You’ll also get 20% off an annual premium subscription. You've seen people run DOOM on everything—from smart fridges to pregnancy tests. But what does it take to run DOOM on a TI-84 Plus graphing calculator? In this video, I dive into the hardware and software architecture of the TI-84, figure out how it's even possible to load and run custom applications, and walk you through what’s actually going on under the hood. Yes, we’re talking Z80 processor, embedded firmware, and just enough reverse engineering. Along the way, I cover: How I got a TI-84 Plus for $7 on eBay Why the TI-83 was a nightmare to work with How calculators run apps like DOOM The software stack (firmware, OS, app layer) Why embedded systems development is full of pain, chaos, and cosmic radiation This video is part technical deep dive, part deadpan humor, and part existential crisis brought on by calculators. If you're into retro computing, low-level programming, or just like watching weird tech experiments, this one’s for you. If you want to help me get better equipment: https://www.patreon.com/tariq10x/ https://x.com/realtariq10x Sources: Z80 Manual: https://www.zilog.com/docs/z80/um0080.pdf TI Calculator Documentation Wiki: https://wikiti.brandonw.net/index.php?title=Calculator_Documentation zDoom Download: https://www.ticalc.org/archives/files/fileinfo/360/36062.html MirageOs Download: https://www.ticalc.org/archives/files/fileinfo/139/13949.html MirageOs Homepage: https://detachedsolutions.com/mirageos/ Calculator tear downs: http://www.datamath.org 00:00 The Rabbit Hole 01:01 Getting the Hardware 03:06 What Even Is This Device 05:06 Hardware 07:14 Bank Switching 13:51 TI-84 vs Gameboy 17:04 Firmware 19:28 B_CALLS 22:03 MirageOS 27:16 Source Code 30:39 Conclusion Song Credits: ------------------------------------------------------------------------------------------------------------------- All songs Licensed under Creative Commons: By Attribution 4.0 License ------------------------------------------------------------------------------------------------------------------- "Rising Tide" Kevin MacLeod (incompetech.com) "Intuit 256" Kevin MacLeod (incompetech.com) "Hard Boiled" Kevin MacLeod (incompetech.com) "Dispersion Relation" Kevin MacLeod (incompetech.com) "Spy Glass" Kevin MacLeod (incompetech.com) "Mesmerizing Galaxy Loop" Kevin MacLeod (incompetech.com) "Lightless Dawn" Kevin MacLeod (incompetech.com)