I wanted a tiny scriptable meltdown proof way to run userspace programs
and visualize how program execution impacts memory. It helps to explain
how things like Actually Portable Executable works. It can show you how
the GCC generated code is going about manipulating matrices and more. I
didn't feel fully comfortable with Qemu and Bochs because I'm not smart
enough to understand them. I wanted something like gVisor but with much
stronger levels of assurances. I wanted a single binary that'll run, on
all major operating systems with an embedded GPL barrier ZIP filesystem
that is tiny enough to transpile to JavaScript and run in browsers too.
https://justine.storage.googleapis.com/emulator625.mp4
Video game emulators seem to convert colors for modern displays poorly.
Check out https://youtu.be/Eds63YbGhDQ?t=481 where we notice in the CRT
displays Super Mario Bros with a blue sky, whereas the PC shows purple.
It's likely b/c NTSC used Illuminant C whereas sRGB uses Illuminant D65.
See the improvement: https://justine.storage.googleapis.com/nesemu3.png
Now you can play video games in the terminal as they looked in the 80's.
This change also reduces CPU usage to a third.
One of the benefits of implementing system call support from scratch is
that we're able to have embedded zip filesystem support which trickles
into libraries such as stdio, without unportable symbolic interposition.
It's also be great if we could say open("gs://bucket/object", O_RDONLY)
for seamless GCS, similar to Java NIO, but abstracted by the C library.