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-WEBVTT
-
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-hello everyone and welcome to my talk
-
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-state of retrogaming and Emacs
-
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-[Music]
-
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-first of all a little bit about myself
-
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-my name is neilman I'm 28 years old
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-I work as a cyber security consultant
-
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-msg systems and
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-test other people's web applications and
-
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-review the source code for security
-
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-problems
-
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-you can reach me by email I have my own
-
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-self-hosted git repositories
-
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-and I have a blog where you can
-
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-occasionally find new posts by me on all
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-kinds of things not just emix things
-
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-so but the motivation about this one I
-
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-found that Emacs is the ultimate
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-procrastination machine and there are
-
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-lots of fun demonstrations I'll go over
-
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-a few of them
-
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-for example someone made a thing to
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-order sell it for himself online so it
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-doesn't have to walk over to the shop
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-there's plenty rc bots there's some game
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-things
-
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-there's an emulator for the z machine
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-which you can use to play zorg
-
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-and so I asked myself at this point can
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-you actually emulate retro games at
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-60fps and it looked around a bit
-
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-and found some projects but none that
-
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-were actually able to
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-do it at 60fps so I set out to do my own
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-one
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-and looked out for a console that you
-
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-can actually emulate at that speed
-
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-using emax with its very very limited
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-rendering
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-[Music]
-
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-and here's the project chip8.el it's
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-pretty much finished
-
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-it clocks into under 1000 sourced lines
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-of code
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-it supports the superchip 8 extensions
-
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-it runs at full speed all games behave
-
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-okay as far as I'm concerned and
-
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-yeah I'm pretty happy with it it's very
-
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-much the hell world of emulation
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-and I might maybe do some other
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-emulation projects in the future
-
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-now for the section which is the longest
-
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-bunch of fun facts about ship a dot el
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-which I've learned
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-during this project so
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-what the hell is debate anyway first of
-
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-all unlike many other emulation game
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-things it's not a console but a vm
-
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-it was designed for easy parting of home
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-computer games
-
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-it wasn't terribly successful and but
-
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-there's still a small community of
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-enthusiasts
-
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-writing games for it and there are even
-
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-a few demos
-
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-this vm has system specs it has a very
-
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-very simple 8-bit cpu with 16 registers
-
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-and
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-36 fixed size instructions you have a
-
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-whole
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-4 kilobyte of ram you have a stack with
-
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-16 return addresses
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-the resolution is 64 by 32 black white
-
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-pixels
-
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-rendering is done by drawing sprites
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-these are drawn in excel mode meaning
-
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-that if you
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-draw a sprite and set a bit it just
-
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-flips over from black to white or white
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-to black
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-first one you have a modern buzz that
-
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-can just beep at one
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-frequency and most unusually there's a
-
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-hexadecimal keypad as input
-
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-so the keys are basically zero to nine
-
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-and a to f
-
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-so how does this whole thing work it
-
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-runs an unspecified speed
-
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-you'll probably have to do some fine
-
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-tune you find the speed you're happy
-
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-with
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-sound and delay timers exist they count
-
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-down at 60fps down to zero
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-this is done so that you can play a
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-sound at some specific time
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-the game itself is loaded with a fixed
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-offset into ram the program account is
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-set to exactly that offset
-
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-and from there it enters the game loop
-
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-where decodes and instruction executes
-
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-it for the side effects and just
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-loops and does this at infinitum
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-[Music]
-
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-so the game was the first thing where
-
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-into problems the usual game approach is
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-to
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-do stuff figure out how long to eight
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-wait for exactly that much and
-
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-repeat this doesn't work well in imax at
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-all because well
-
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-user input basically and
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-Emacs is designed to just do whatever it
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-needs to do whenever you enter use input
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-instead of
-
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-doing things at one specific time if you
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-try to do
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-interruptable sleep well you get
-
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-unpredictable behavior
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-for example can be the timer doesn't run
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-at all at next time because you've
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-accidentally cancelled it
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-if you do uninterruptable sleep it's
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-freezes instead which isn't what you
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-want either
-
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-so I went for timers which forced me to
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-do inversion of control
-
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-meaning that I have to write code in the
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-style where it's just call it
-
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-time and this allows this input to
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-happen and to
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-for things to progress at roughly the
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-speed I want to
-
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-so there's the skydiver function which
-
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-is called a 60fps
-
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-and I have to be very careful to not do
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-too much in it
-
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-and say this function execute cpu cycles
-
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-decrypt the sound delay registers and
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-redraw
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-the screen so to map this whole system
-
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-to mx lisp
-
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-I've used just integers and vectors
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-which contain even more integers
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-this is used for the ram registers
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-return stack key state screen and so on
-
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-and so forth basically
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-what you would do if you were writing c
-
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-all of this is stored in global
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-variables I'm not using any
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-lists at all and as a side effect
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-there's no constant going on at all
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-there are no extra objects created which
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-would trigger
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-garbage collection pulses this getting
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-this red was rather tricky actually and
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-there were some
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-in garbage collection problems which I
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-had to resolve over time
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-so the coding instructions for this you
-
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-have to know that all instructions are
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-two bytes long
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-and the arguments encoded inside them
-
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-for example the jump to address
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-instruction
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-is encoded as one and three hex digits
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-the type is extracted masking with f000
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-and then shifting it by 12 bits mask
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-means the hd
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-performance binary end you can do the
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-same with the argument basement with
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-zero fff
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-and no shift if you do this long enough
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-you'll find common patterns for example
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-addresses are always encoded like this
-
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-using the last three nibbles in the code
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-you'll find a big count which dispatches
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-on the type and executes it for the side
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-effects
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-[Music]
-
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-for testing I've initially just accused
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-the rom until I fit ctrl g
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-and then use the debug command to run
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-the screen to a buffer
-
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-later on I found tiny roms that just
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-display a static
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-test screen for example logo and looked
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-whether it looked right
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-I added instructions as needed and went
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-through more and more and more roms and
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-later I wrote in unit test suite as a
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-safety net and this unit test suite it
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-just
-
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-sets up an empty emulator state executes
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-some instructions and then looks whether
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-the
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-expected side effects have happened
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-for debugging I usually use e-debug but
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-this was super ineffective because well
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-you don't really want to step through
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-big cons doing side effects for every
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-single cycle when it can take like 100
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-cycles for things to happen
-
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-therefore I've set up logging and
-
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-whenever I locked something
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-and couldn't figure out the error I
-
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-compared my lock output with
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-instrumented version of another emulator
-
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-and if the locks diverge then I have
-
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-figured out where the bug lies and could
-
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-look deeper into it
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-future project idea might be a chip 8
-
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-debugger but I doubt I'll ever
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-go into it for analysis I initially
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-wrote a disassembler which is a very
-
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-simple thing but super tedious
-
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-especially if you wanted to add advanced
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-functionality for example analysis or
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-thinking of what part is data what had
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-this code
-
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-and I had this great idea for using the
-
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-radari 2 framework
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-and adding analysis and disassembly
-
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-plug-in for it
-
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-so I looked into this found okay here
-
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-where you can write plugins in c
-
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-but also in python so I wrote one in
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-python and then the scout there's
-
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-actually existing one in core which you
-
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-have to enable explicitly by passing its
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-argument so I've tried it and found it's
-
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-not exactly as good as my own one so
-
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-improved this one and submitted pull
-
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-requests until it was at the same level
-
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-[Music]
-
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-rendering was the trickiest part of this
-
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-whole thing because
-
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-well I decided against using a library
-
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-not like there would have been any
-
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-usable library for this
-
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-my usual approach of accelerating svg
-
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-file was too expensive it just created
-
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-too much garbage and took too long time
-
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-I then tried creating mutating strings
-
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-this was either either too expensive
-
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-just like svgs or too complicated I
-
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-tried changing svg tiles which created
-
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-gaps between the lines
-
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-then I tried to create an xpm file which
-
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-was backed by a bull vector
-
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-administrating this bull vector
-
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-but the image caching effect made it
-
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-just every nth frame to appear which
-
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-wasn't good either then I had the idea
-
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-to just use plain text
-
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-and paint the individual characters with
-
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-a different background color this
-
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-this had perfect perfect performance
-
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-there were many optimization attempts
-
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-until I got there and it was
-
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-very very stressful I wasn't sure
-
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-whether I would ever get to accept the
-
-00:08:23.199 --> 00:08:26.160
-performance at all
-
-00:08:26.160 --> 00:08:28.560
-for sound you only need to a single beep
-
-00:08:28.560 --> 00:08:30.319
-so technically it shouldn't be difficult
-
-00:08:30.319 --> 00:08:31.280
-to emulate it
-
-00:08:31.280 --> 00:08:33.519
-however doing this is hard because Emacs
-
-00:08:33.519 --> 00:08:34.880
-officially only supports synchronous
-
-00:08:34.880 --> 00:08:37.200
-playback of sounds
-
-00:08:37.200 --> 00:08:39.039
-but there's also emax process which you
-
-00:08:39.039 --> 00:08:41.360
-can launch in asynchronous way
-
-00:08:41.360 --> 00:08:43.519
-so I looked into it and found that
-
-00:08:43.519 --> 00:08:45.279
-employee has a slave mode and mpv
-
-00:08:45.279 --> 00:08:46.640
-supports listing on the
-
-00:08:46.640 --> 00:08:50.880
-fifo for commands so I've created a pipe
-
-00:08:50.880 --> 00:08:54.000
-started a past mpv in loop mode and
-
-00:08:54.000 --> 00:08:55.519
-always send in pause and pause command
-
-00:08:55.519 --> 00:08:58.000
-to the fifo and that way I could control
-
-00:08:58.000 --> 00:09:02.640
-when to start beeping and stop beeping
-
-00:09:02.640 --> 00:09:05.760
-so yeah that's it so far was a very
-
-00:09:05.760 --> 00:09:07.200
-educational experience
-
-00:09:07.200 --> 00:09:09.279
-I have tried out a bunch of games which
-
-00:09:09.279 --> 00:09:10.320
-were
-
-00:09:10.320 --> 00:09:12.640
-well I almost say the worst ports of
-
-00:09:12.640 --> 00:09:14.320
-classic games I've ever tried
-
-00:09:14.320 --> 00:09:15.839
-it wasn't terribly fun to play them but
-
-00:09:15.839 --> 00:09:18.320
-was fun to improve the emulator until
-
-00:09:18.320 --> 00:09:21.760
-well things worked good enough
-
-00:09:21.760 --> 00:09:23.279
-and I've learned a lot about how
-
-00:09:23.279 --> 00:09:25.120
-computers work at this level
-
-00:09:25.120 --> 00:09:27.760
-so maybe maybe I'll in the future make
-
-00:09:27.760 --> 00:09:28.880
-another emulator
-
-00:09:28.880 --> 00:09:31.920
-but uh I'm not sure whether anything
-
-00:09:31.920 --> 00:09:34.000
-more advanced like intel 8080 emulator
-
-00:09:34.000 --> 00:09:36.560
-will actually run mix fast enough
-
-00:09:36.560 --> 00:09:37.839
-but it's still an interesting idea
-
-00:09:37.839 --> 00:09:39.200
-because then you could actually have an
-
-00:09:39.200 --> 00:09:39.600
-os
-
-00:09:39.600 --> 00:09:41.680
-inside Emacs and fulfill that one
-
-00:09:41.680 --> 00:09:43.120
-specific meme
-
-00:09:43.120 --> 00:09:45.440
-but if I try to do most serious stuff
-
-00:09:45.440 --> 00:09:47.279
-I'll probably use chicken scheme which
-
-00:09:47.279 --> 00:09:48.000
-is my
-
-00:09:48.000 --> 00:09:49.920
-preferred language for serious projects
-
-00:09:49.920 --> 00:09:53.279
-and writing neso gamer emulator
-
-00:09:53.279 --> 00:09:57.839
-and that's it thank you
diff --git a/2020/subtitles/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8--vasilij-wasamasa-schneidermann.vtt b/2020/subtitles/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8--vasilij-wasamasa-schneidermann.vtt
new file mode 100644
index 00000000..3d655630
--- /dev/null
+++ b/2020/subtitles/emacsconf-2020--27-state-of-retro-gaming-in-emacs-chip8--vasilij-wasamasa-schneidermann.vtt
@@ -0,0 +1,630 @@
+WEBVTT
+
+00:00:00.880 --> 00:00:04.520
+Hello everyone and welcome to my talk, "The State of Retro Gaming and Emacs."
+
+00:00:06.960 --> 00:00:08.639
+First of all, a little bit about myself.
+
+00:00:08.639 --> 00:00:12.000
+My name is Vasilij Schneidermann. I'm 28 years old.
+
+00:00:12.000 --> 00:00:14.719
+I work as a cyber security consultant at msg systems,
+
+00:00:14.719 --> 00:00:17.359
+and test other people's web applications
+
+00:00:17.359 --> 00:00:20.160
+and review the source code for security problems.
+
+00:00:20.160 --> 00:00:22.080
+You can reach me by email.
+
+00:00:22.080 --> 00:00:25.039
+I have my own self-hosted git repositories,
+
+00:00:25.039 --> 00:00:28.160
+and I have a blog where you can occasionally find new posts by me
+
+00:00:28.160 --> 00:00:32.160
+on all kinds of things, not just Emacs things.
+
+00:00:32.160 --> 00:00:34.559
+The motivation about this one...
+
+00:00:34.559 --> 00:00:37.600
+I found that Emacs is the ultimate procrastination machine,
+
+00:00:37.600 --> 00:00:39.600
+and there are lots of fun demonstrations.
+
+00:00:39.600 --> 00:00:41.200
+I'll go over a few of them.
+
+00:00:41.200 --> 00:00:45.840
+For example, someone made a thing to order salad for himself online,
+
+00:00:45.840 --> 00:00:48.239
+so he doesn't have to walk over to the shop.
+
+00:00:48.239 --> 00:00:51.760
+There's plenty of IRC bots. There's some game things.
+
+00:00:51.760 --> 00:00:55.600
+There's an emulator for the Z-machine
+which you can use to play zork.
+
+00:00:55.600 --> 00:00:57.440
+And so I asked myself, at this point,
+
+00:00:57.440 --> 00:00:59.920
+can you actually emulate retro games at 60fps?
+
+00:00:59.920 --> 00:01:02.079
+I looked around a bit and found some projects,
+
+00:01:02.079 --> 00:01:06.159
+but none that were actually able to do it at 60fps.
+
+00:01:06.159 --> 00:01:08.000
+So I set out to do my own one,
+
+00:01:08.000 --> 00:01:09.200
+and looked out for a console
+
+00:01:09.200 --> 00:01:11.119
+that you can actually emulate at that speed,
+
+00:01:11.119 --> 00:01:14.690
+using Emacs with its very, very limited rendering.
+
+00:01:16.320 --> 00:01:19.200
+And here's the project, chip8.el.
+
+00:01:19.200 --> 00:01:20.560
+It's pretty much finished.
+
+00:01:20.560 --> 00:01:24.000
+It clocks into under 1000 source lines of code.
+
+00:01:24.000 --> 00:01:26.159
+It supports the superchip 8 extensions.
+
+00:01:26.159 --> 00:01:27.280
+It runs at full speed.
+
+00:01:27.280 --> 00:01:29.600
+All games behave okay, as far as I'm concerned,
+
+00:01:29.600 --> 00:01:31.680
+and yeah, I'm pretty happy with it.
+
+00:01:31.680 --> 00:01:34.479
+It's very much the hello world of emulation,
+
+00:01:34.479 --> 00:01:40.880
+and I might, maybe, do some other emulation projects in the future.
+
+00:01:40.880 --> 00:01:43.360
+Now, for the section which is the longest:
+
+00:01:43.360 --> 00:01:45.439
+bunch of fun facts about chip8.el
+
+00:01:45.439 --> 00:01:49.200
+which I've learned during this project.
+
+00:01:49.200 --> 00:01:51.759
+So what the hell is chip8 anyway?
+
+00:01:51.759 --> 00:01:54.960
+First of all, unlike many other emulation game things,
+
+00:01:54.960 --> 00:01:56.799
+it's not a console, but a VM.
+
+00:01:56.799 --> 00:02:00.000
+It was designed for easy porting of home
+computer games.
+
+00:02:00.000 --> 00:02:02.320
+It wasn't terribly successful,
+
+00:02:02.320 --> 00:02:05.439
+but there's still a small community of enthusiasts writing games for it,
+
+00:02:05.439 --> 00:02:09.119
+and there are even a few demos.
+
+00:02:09.119 --> 00:02:11.039
+This VM has system specs.
+
+00:02:11.039 --> 00:02:14.720
+It has a very, very simple 8-bit cpu with 16 registers,
+
+00:02:14.720 --> 00:02:17.280
+and 36 fixed-size instructions.
+
+00:02:17.280 --> 00:02:19.680
+You have a whole 4 kilobyte of RAM.
+
+00:02:19.680 --> 00:02:22.080
+You have a stack with 16 return addresses.
+
+00:02:22.080 --> 00:02:25.760
+The resolution is 64 by 32 black/white pixels.
+
+00:02:25.760 --> 00:02:28.000
+Rendering is done by drawing sprites.
+
+00:02:28.000 --> 00:02:29.200
+These are drawn in XOR mode,
+
+00:02:29.200 --> 00:02:31.840
+meaning that if you draw a sprite and set a bit,
+
+00:02:31.840 --> 00:02:35.040
+it just flips over from black to white or white to black.
+
+00:02:35.040 --> 00:02:39.360
+For sound, you have a monotone buzzer that can just beep at one frequency.
+
+00:02:39.360 --> 00:02:43.120
+Most unusually, there's a hexadecimal keypad as input,
+
+00:02:43.120 --> 00:02:48.480
+so the keys are basically zero to nine and a to f.
+
+00:02:48.480 --> 00:02:50.720
+So how does this whole thing work?
+
+00:02:50.720 --> 00:02:52.400
+It runs at an unspecified speed.
+
+00:02:52.400 --> 00:02:53.040
+You'll probably have to do some fine-tuning
+
+00:02:53.040 --> 00:02:56.080
+to find the speed you're happy with.
+
+00:02:56.080 --> 00:02:58.080
+Sound and delay timers exist.
+
+00:02:58.080 --> 00:03:01.120
+They count down at 60fps down to 0.
+
+00:03:01.120 --> 00:03:05.120
+This is done so that you can play a sound at some specific time.
+
+00:03:05.120 --> 00:03:07.840
+The game itself is loaded with a fixed offset into RAM.
+
+00:03:07.840 --> 00:03:10.480
+The program counter is set to exactly that offset,
+
+00:03:10.480 --> 00:03:11.920
+and from there it enters the game loop
+
+00:03:11.920 --> 00:03:13.280
+where it decodes an instruction,
+
+00:03:13.280 --> 00:03:14.800
+executes it for the side effects,
+
+00:03:14.800 --> 00:03:18.130
+and just loops and does this ad infinitum.
+
+00:03:19.599 --> 00:03:22.720
+So the game loop was the first thing where we ran into problems.
+
+00:03:22.720 --> 00:03:25.120
+The usual game approach is to do stuff,
+
+00:03:25.120 --> 00:03:26.640
+figure out how long to wait,
+
+00:03:26.640 --> 00:03:29.280
+wait for exactly that much, and repeat.
+
+00:03:29.280 --> 00:03:31.680
+This doesn't work well in Emacs at all, because, well,
+
+00:03:31.680 --> 00:03:34.959
+user input, basically.
+
+00:03:34.959 --> 00:03:37.760
+Emacs is designed to just do whatever it needs to do
+
+00:03:37.760 --> 00:03:39.040
+whenever you enter user input
+
+00:03:39.040 --> 00:03:42.319
+instead of doing things at one specific time.
+
+00:03:42.319 --> 00:03:46.640
+If you try to do interruptable sleep, well, you get unpredictable behavior.
+
+00:03:46.640 --> 00:03:50.480
+For example, it can be the timer doesn't run at all at the next time
+
+00:03:50.480 --> 00:03:52.560
+because you've accidentally cancelled it.
+
+00:03:52.560 --> 00:03:55.120
+If you do uninterruptable sleep, it freezes instead ,
+
+00:03:55.120 --> 00:03:56.720
+which isn't what we want either.
+
+00:03:56.720 --> 00:04:00.560
+So I went for timers, which forced me to do inversion of control,
+
+00:04:00.560 --> 00:04:02.560
+meaning that I have to write code in the style
+
+00:04:02.560 --> 00:04:04.879
+where it just calls timer,
+
+00:04:04.879 --> 00:04:06.560
+and this allows this input to happen
+
+00:04:06.560 --> 00:04:11.040
+and for things to progress at roughly the speed I want to.
+
+00:04:11.040 --> 00:04:14.159
+So there's the timer function which is called at 60fps
+
+00:04:14.159 --> 00:04:17.359
+and I have to be very careful to not do too much in it.
+
+00:04:17.359 --> 00:04:21.305
+And, say, this function executes CPU cycles,
+
+00:04:21.305 --> 00:04:26.479
+decrement the sound/delay registers, and redraw the screen.
+
+00:04:26.479 --> 00:04:28.800
+So to map this whole system to Emacs Lisp,
+
+00:04:28.800 --> 00:04:31.199
+I've used just integers and vectors
+
+00:04:31.199 --> 00:04:33.120
+which contain even more integers.
+
+00:04:33.120 --> 00:04:35.040
+This is used for the RAM, registers,
+
+00:04:35.040 --> 00:04:37.040
+return stack, key state, screen,
+
+00:04:37.040 --> 00:04:38.508
+and so on and so forth.
+
+00:04:38.508 --> 00:04:41.520
+Basically, what you would do if you were writing C.
+
+00:04:41.520 --> 00:04:43.360
+All of this is stored in global variables.
+
+00:04:43.360 --> 00:04:45.600
+I'm not using any lists at all.
+
+00:04:45.600 --> 00:04:48.400
+As a side effect, there's no consing going on at all.
+
+00:04:48.400 --> 00:04:50.080
+There are no extra objects created
+
+00:04:50.080 --> 00:04:53.199
+which would trigger garbage collection processes.
+
+00:04:53.199 --> 00:04:55.600
+Getting this right was rather tricky, actually,
+
+00:04:55.600 --> 00:04:58.240
+and there were some hidden garbage collection problems
+
+00:04:58.240 --> 00:05:01.759
+which I had to resolve over time.
+
+00:05:01.759 --> 00:05:03.759
+So, decoding instructions.
+
+00:05:03.759 --> 00:05:06.800
+For this, you have to know that all instructions are two bytes long,
+
+00:05:06.800 --> 00:05:08.880
+and the arguments are encoded inside them.
+
+00:05:08.880 --> 00:05:11.440
+For example, the jump to address instruction
+
+00:05:11.440 --> 00:05:15.120
+is encoded as one and three hex digits.
+
+00:05:15.120 --> 00:05:18.400
+The type is extracted masking with #xF000
+
+00:05:18.400 --> 00:05:20.400
+and then shifting it by 12 bits.
+
+00:05:20.400 --> 00:05:23.520
+Mask means you perform the binary AND.
+
+00:05:23.520 --> 00:05:28.400
+You can do the same with the argument by masking with #0xFFF and no shift.
+
+00:05:28.400 --> 00:05:30.560
+If you do this long enough, you'll find common patterns.
+
+00:05:30.560 --> 00:05:32.639
+For example, addresses are always encoded like this
+
+00:05:32.639 --> 00:05:34.880
+using the last three nibbles.
+
+00:05:34.880 --> 00:05:36.160
+In the code, you'll find a big cond
+
+00:05:36.160 --> 00:05:40.070
+which dispatches on the type and executes it for the side effects.
+
+00:05:41.440 --> 00:05:45.919
+For testing, I've initially just executed the ROM until I've hit C-g,
+
+00:05:45.919 --> 00:05:49.039
+and then use the debug command to render the screen to a buffer.
+
+00:05:49.039 --> 00:05:53.199
+Later on, I found tiny ROMs that just display a static test screen,
+
+00:05:53.199 --> 00:05:57.280
+for example, logo, and looked whether it looked right.
+
+00:05:57.280 --> 00:05:58.800
+I added instructions as needed
+
+00:05:58.800 --> 00:06:00.720
+and went through more and more and more ROMs.
+
+00:06:00.720 --> 00:06:04.000
+And later I wrote a unit test suite as a safety net.
+
+00:06:04.000 --> 00:06:07.840
+This unit test suite, it just sets up an empty emulator state,
+
+00:06:07.840 --> 00:06:09.199
+executes some instructions,
+
+00:06:09.199 --> 00:06:14.880
+and then looks whether the expected side effects have happened.
+
+00:06:14.880 --> 00:06:18.319
+For debugging, I usually use edebug, but this was super ineffective,
+
+00:06:18.319 --> 00:06:21.600
+because, well, you don't really want to step through big cons
+
+00:06:21.600 --> 00:06:23.680
+doing side effects for every single cycle,
+
+00:06:23.680 --> 00:06:26.880
+when it can take like 100 cycles for things to happen.
+
+00:06:26.880 --> 00:06:29.680
+Therefore I've set up logging.
+
+00:06:29.680 --> 00:06:32.639
+Whenever I logged something and couldn't figure out the error,
+
+00:06:32.639 --> 00:06:37.039
+I compared my log output with the instrumented version of another emulator,
+
+00:06:37.039 --> 00:06:40.479
+and if the logs diverge, then I have figured out where the bug lies
+
+00:06:40.479 --> 00:06:42.720
+and could look deeper into it.
+
+00:06:42.720 --> 00:06:44.960
+Future project idea might be a chip 8 debugger,
+
+00:06:44.960 --> 00:06:49.440
+but I doubt I'll ever go into it.
+
+00:06:49.440 --> 00:06:51.759
+For analysis, I initially wrote a disassembler,
+
+00:06:51.759 --> 00:06:54.400
+which is a very simple thing but super tedious,
+
+00:06:54.400 --> 00:06:56.639
+especially if you wanted to add advanced functionality,
+
+00:06:56.639 --> 00:06:58.720
+for example, analysis or thinking of what part is data,
+
+00:06:58.720 --> 00:07:00.000
+what part is code.
+
+00:07:00.000 --> 00:07:03.360
+I had this great idea for using the radare 2 framework
+
+00:07:03.360 --> 00:07:06.479
+and adding analysis and disassembly plug-in for it.
+
+00:07:06.479 --> 00:07:08.400
+So I looked into this. Found, okay,
+
+00:07:08.400 --> 00:07:10.319
+you can write plugins in C
+
+00:07:10.319 --> 00:07:12.639
+but also in Python, so I wrote one in Python,
+
+00:07:12.639 --> 00:07:14.720
+and then discovered there's actually an existing one in core,
+
+00:07:14.720 --> 00:07:18.400
+which you have to enable explicitly by passing an extra argument.
+
+00:07:18.400 --> 00:07:21.680
+I've tried it and found it's not exactly as good as my own one,
+
+00:07:21.680 --> 00:07:24.160
+so I improved this one and submitted pull requests
+
+00:07:24.160 --> 00:07:26.610
+until it was at the same level.
+
+00:07:28.080 --> 00:07:30.720
+Rendering was the trickiest part of this whole thing,
+
+00:07:30.720 --> 00:07:34.319
+because, well, I decided against using a library.
+
+00:07:34.319 --> 00:07:37.120
+Not like there would have been any usable library for this.
+
+00:07:37.120 --> 00:07:40.880
+My usual approach of creating SVG files was too expensive.
+
+00:07:40.880 --> 00:07:45.120
+It just created too much garbage and took too long time.
+
+00:07:45.120 --> 00:07:47.360
+I then tried creating mutating strings.
+
+00:07:47.360 --> 00:07:52.479
+This was either too expensive, just like SVGs, or too complicated.
+
+00:07:52.479 --> 00:07:57.280
+I tried changing SVG tiles, which created gaps between the lines.
+
+00:07:57.280 --> 00:08:00.720
+Then I tried to create an xpm file which was backed by a bool vector
+
+00:08:00.720 --> 00:08:02.400
+and mutating this bool vector,
+
+00:08:02.400 --> 00:08:04.000
+but the image caching effect
+
+00:08:04.000 --> 00:08:06.479
+made it just every nth frame to appear,
+
+00:08:06.479 --> 00:08:08.879
+which wasn't good either.
+
+00:08:08.879 --> 00:08:11.440
+Then I had the idea to just use plain text
+
+00:08:11.440 --> 00:08:13.120
+and paint the individual characters
+
+00:08:13.120 --> 00:08:14.800
+with a different background color.
+
+00:08:14.800 --> 00:08:17.120
+This had perfect, perfect performance.
+
+00:08:17.120 --> 00:08:19.280
+There were many optimization attempts until I got there,
+
+00:08:19.280 --> 00:08:21.199
+and it was very, very stressful.
+
+00:08:21.199 --> 00:08:26.160
+I wasn't sure whether I would ever get to accept the performance at all.
+
+00:08:26.160 --> 00:08:28.560
+For sound you only need to do a single beep,
+
+00:08:28.560 --> 00:08:31.280
+so technically, it shouldn't be difficult to emulate it.
+
+00:08:31.280 --> 00:08:33.039
+However, doing this is hard because
+
+00:08:33.039 --> 00:08:37.200
+Emacs officially only supports synchronous playback of sounds.
+
+00:08:37.200 --> 00:08:41.360
+But there's also Emacs process, which you can launch in asynchronous way.
+
+00:08:41.360 --> 00:08:44.720
+So I looked into it and found that mplayer has a slave mode
+
+00:08:44.720 --> 00:08:48.640
+and mpv supports listing on the fifo for commands.
+
+00:08:48.640 --> 00:08:53.760
+So I've created a pipe, started a paused MPV in loop mode,
+
+00:08:53.760 --> 00:08:56.560
+and always send in pause and unpause command to the FIFO,
+
+00:08:56.560 --> 00:08:58.000
+and that way I could control
+
+00:08:58.000 --> 00:09:02.640
+when to start beeping and stop beeping.
+
+00:09:02.640 --> 00:09:04.160
+So yeah, that's it so far.
+
+00:09:04.160 --> 00:09:07.200
+It was a very educational experience.
+
+00:09:07.200 --> 00:09:10.320
+I have tried out a bunch of games which were,
+
+00:09:10.320 --> 00:09:14.320
+well, I almost say the worst ports of classic games I've ever tried.
+
+00:09:14.320 --> 00:09:15.680
+It wasn't terribly fun to play them,
+
+00:09:15.680 --> 00:09:18.555
+but was fun to improve the emulator
+
+00:09:18.555 --> 00:09:21.760
+until, well, things worked good enough.
+
+00:09:21.760 --> 00:09:25.120
+I've learned a lot about how computers work at this level,
+
+00:09:25.120 --> 00:09:28.880
+so, maybe, maybe I'll in the future make another emulator,
+
+00:09:28.880 --> 00:09:34.000
+but I'm not sure whether anything more advanced, like an Intel 8080 emulator,
+
+00:09:34.000 --> 00:09:36.560
+will actually run in Emacs fast enough,
+
+00:09:36.560 --> 00:09:37.839
+but it's still an interesting idea,
+
+00:09:37.839 --> 00:09:40.800
+because then you could actually have an OS inside Emacs
+
+00:09:40.800 --> 00:09:43.120
+and fulfill that one specific meme.
+
+00:09:43.120 --> 00:09:45.440
+But if I try to do most serious stuff,
+
+00:09:45.440 --> 00:09:47.040
+I'll probably use Chicken Scheme,
+
+00:09:47.040 --> 00:09:49.920
+which is my preferred language for serious projects,
+
+00:09:49.920 --> 00:09:53.279
+and write a NES game emulator.
+
+00:09:53.279 --> 00:09:57.839
+And that's it. Thank you.