*Screenception*

Visualizing programs with side-effects in a postfix shell with a live-updating text-mode environment. Built all the way up from machine code without any dependencies (except an x86 processor and Linux kernel).

https://archive.org/details/akkartik-2min-2020-11-12

Project page: https://github.com/akkartik/mu

More context: https://mastodon.social/@akkartik/104896128141863951

*Editing functions in the Mu shell*

https://archive.org/details/akkartik-2min-2020-12-06

Long delay since my last video. Printing floating-point numbers is *really* hard. I'm still half-assing it.

As a follow-up to https://merveilles.town/@akkartik/105331619408248578, I'm tightening focus to two threads:

a) These Mu shell experiments, and
b) An extremely skeletal OS to drop the Linux kernel dependency.

Deprioritized for now:
a) Other processors: RISCV, ARM, RPi, etc.
b) Graphics, mouse, etc. Device priorities for the OS are disk then ethernet.

*Towards running Mu without Linux*

All Mu really needs so far is to print to screen and read from the keyboard. Here's a 2-minute video about achieving that:

https://archive.org/details/akkartik-2min-2020-12-24

It seems such a small thing. But I needed lots of help, as you can see from the additions to my credits: https://github.com/akkartik/mu/compare/670cbb3d33807efb2d5e0db9e54ffed42f7ef0e3..main?short_path=b335630#diff-b335630551682c19a781afebcf4d07bf978fb1f8ac04c6bf87428ed5106870f5

Merry Christmas to all! What a beautiful world.

Project page: https://github.com/akkartik/mu

More context: https://mastodon.social/@akkartik/104896128141863951

*Switching gears to pure graphics*

Until now Mu has followed classic Unix: stdin, stdout, pure text mode.

But giving up an OS kernel requires controlling the screen myself. Which requires various complicated probing for hardware. Then programs handling various screen sizes.

Easier: just always assume some common graphics mode. Say 1024x768 with 256 colors.

Interestingly, the default palette has far fewer than 256 colors. (Pic: 1024 cols each contain color `col%256`.)

http://akkartik.github.io/mu/html/baremetal/ex2.hex.html

*2020: Flood-filling the Mu computer*

A year ago I had a prototype of a C-level programming language mapping 1:1 to Assembly that I _thought_ could be type-safe.

Since then, I:

* wrote an academic paper on it
* made it type-safe
* began a high-level language atop it
* got into video, with 15 2-minute screencasts
* and ran programs written in it on bare metal, without an OS, like, 5 years before I expected to.

❤️ to everyone who inspired, taught, debated, encouraged.

https://github.com/akkartik/mu

My 2020 wrap-up is turning into a bit of a rabbit hole:

http://akkartik.name/post/mu-2020

I ended up trying to create a Wardley Map (https://en.wikipedia.org/wiki/Wardley_map) for Mu.

https://github.com/akkartik/mu

*Rendering text atop baremetal*

Mu can now render text atop baremetal x86.

Try clicking around from http://akkartik.github.io/mu/html/baremetal/ex5.mu.html

The boot-up machine code reads a few sectors from disk, configures a keyboard handler, and loads a bitmap font (2KB for ASCII, with the option for more).

I use GNU Unifont. I believe that means Mu is now GPL v2. So stated. IANAL and I try not to think about software IP. But a font? Copyright seems reasonable there.

Next up: a text editor!

https://github.com/akkartik/mu

*A more international interface for rendering text*

New 2-minute video: https://archive.org/details/akkartik-2min-2021-01-12

You get just one fixed screen resolution: 1024x768, 256 colors. Widely available on modern machines, no drivers needed.

You get just one fixed-width bitmap font. No bold/italics, no anti-aliasing.

BUT it won't make assumptions about English and left-to-right order. I eventually want anybody to be able to customize it to their language.

Main project page: https://github.com/akkartik/mu

I've been trying to visualize the default 256-color palette I get on baremetal.

http://akkartik.github.io/mu/html/baremetal/vga_palette.html

To my eyes it looks like I can/should just live in the first 128 colors.

I built a game of "snakes", but it came out more like an etch-a-sketch 😄

http://akkartik.github.io/mu/html/baremetal/ex7.mu.html

Play it on any non-windows:

```
git clone https://github.com/akkartik/mu
cd mu
./translate_mu_baremetal_emulated baremetal/ex7.mu
qemu-system-i386 disk.img
```

h/j/k/l to draw

I made an art! On a computer without an OS.

https://github.com/akkartik/mu

It took a while, but I've finally ported a pre-existing Mu program to baremetal: an RPN calculator.

This was _hard_, purely because of cursor management. I have a greater appreciation for everything that display hardware and terminal emulators provide for text mode. Mu so far puts the onus on the programmer.

http://akkartik.github.io/mu/html/baremetal/rpn.mu.html

In the end it's interesting to visualize the changes I had to make:

vim -d apps/rpn.mu baremetal/rpn.mu

They're entirely in `main`; the rest is unchanged.

I've been reimplementing my from-scratch live-updating postfix shell to _really_ from scratch (no more OS kernel), while at the same time rewriting the prototype with lots of tests and actually giving the language some sort of rigorous basis. No demos yet, but in the meantime here's Conway's Game of Life running on baremetal Mu.

https://archive.org/details/akkartik-mu-life-2021-02-13

Sources: http://akkartik.github.io/mu/html/baremetal/life.mu.html

Main project page: https://github.com/akkartik/mu

The Mu shell is now off Linux

https://archive.org/details/akkartik-mu-shell-20210214

Starting point for the sources: http://akkartik.github.io/mu/html/baremetal/shell/line.mu.html

The architecture is now much cleaner. Functions contain lines, lines contain words, words contain gap buffers. Rendering a thing renders its constituent things. Render takes a top-left coordinate and returns a bottom-right coordinate. Each thing knows which constituent thing has its cursor, shows its cursor when rendering, redirects incoming keystrokes to it.

https://github.com/akkartik/mu