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

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/>


## More on the alt-stream: <https://live.emacsconf.org/alt.html>