# State of Retro Gaming in Emacs
Vasilij "wasamasa" Schneidermann

[[!template id=vid src="https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8--vasilij-wasamasa-schneidermann.webm"]]  
[Download compressed .webm video (7.2M)](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/smaller/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8--vasilij-wasamasa-schneidermann--vp9-q56-video-original-audio.webm)

- [chip8 demo - alien, .webm video, 720p, 2M](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-alien--vasilij-wasamasa-schneidermann.webm)
- [chip8 demo - brix, .webm video, 720p, 1M](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-brix--vasilij-wasamasa-schneidermann.webm)
- [chip8 demo - car, .webm, 720p, 1M](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-car--vasilij-wasamasa-schneidermann.webm)
- [chip8 demo - joust, .webm video, 720p, 2M](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-joust--vasilij-wasamasa-schneidermann.webm)
- [chip8 demo - kaleidoscope, video, 720p, 2M](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-kaleidoscope--vasilij-wasamasa-schneidermann.webm)
- [chip8 demo - sierpinski, video, 720p, 357K](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-sierpinski--vasilij-wasamasa-schneidermann.webm)
- [chip8 demo - tetris, video, 720p, 843K](https://mirror.csclub.uwaterloo.ca/emacsconf/2020/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8-demo-tetris--vasilij-wasamasa-schneidermann.webm)

Many jokes have been made about the true nature of Emacs, such as it
being a fully-fledged operating system.  This talk will demonstrate
its suitability for playing retro games, then explore the inner
workings of a [CHIP-8](https://en.wikipedia.org/wiki/CHIP-8) emulator capable of smooth video game emulation.

[1]: <https://depp.brause.cc/talks/chicken-saar/>
[2]: <https://depp.brause.cc/talks/openchaos-2019-11/>

<!-- from the pad --->

- Actual start and end time (EST): Start: 2020-11-29T13.23.01; End:
  2020-11-29T13.33.00
- Alternative stream for extended talk:
  <http://live.emacsconf.org/alt.html> or
  <http://live0.emacsconf.org/alt.webm>.

# Questions

## Q5: Do you think would be possible to write some compiler in order to write chip-8 games on elisp?
It could be possible if you restrict yourself to some very limited
Elisp subset or lispy assembler. For the latter, here's some projects
to draw inspiration from:

- <https://ahefner.livejournal.com/20528.html>.
- <http://www.dustmop.io/blog/2019/09/10/what-remains-technical-breakdown/>
  ->
  <http://www.pawfal.org/dave/blog/2016/05/a-6502-lisp-compiler-sprite-animation-and-the-nesfamicom/>.
- <https://en.wikipedia.org/wiki/Game_Oriented_Assembly_Lisp> ->
  <https://blog.jakspeedruns.com/opengoal-project-update-september-2020/>.

## Q4: What's the biggest perf bottleneck for your emulator? does it spend time executing your Lisp or something else in the Emacs infrastructure (eg redisplay)?
Redisplay was super slow, it's like 3-4x as slow as executing the CPU
cycles.

- Okay that's the reason why GCCEmacs does not help :)

## Q3: Do you think that you make our tiny console based in the chip ATMega like Arduboy?
I'm sorry, I didn't quite understand the question, could you please
clarify it? I'm not exactly a hardware person, might have to defer it
to someone else.

I've looked at Arduboy and I believe the DEFCON CHIP-8 Badge is the
closest to this:
<https://hackaday.io/project/19121-andxor-dc25-badge/log/53223-chip8-schip-game-emulation>

## Q2: Any tutorial to start? I want to make my game now, no, for chip8
I'm not aware of tutorials, but there's CHIP-8 resources online. You
can of course study the assembly of existing games, that's how I
figured out the tricks that broke my emulator :>

## Q1: How did you manage to present a game engine without showing any game? :-) Show us!!
See the alt stream, it has several demos not shown due to time
constraints.

# Notes
- Slides available at <https://depp.brause.cc/talks/emacsconf-2020/>.
- Repository available at <https://depp.brause.cc/chip8.el/>.
- Blog post available at
  <https://emacsninja.com/posts/smooth-video-game-emulation-in-emacs.html>.