8 ms·

Mu: A Human-Scale Computer

152 points by finite_jest 5y ago

spicybright 5y ago
I feel like the idea could be covered by commodore 64. Even adding basic networking in any way opens up an absolutely massive amount of un-abstracted concepts and processes to keep in one head. That said I flippin love people re-inventing a computer into something not derived from a VAX timeshare machine from the 70s.
- selfhoster11 5y ago
  The main issue with older machines is that the resolution isn't great for writing. I like reasonable letter shapes, and you kind of need 640x480 for that at least.
  - finite_jest 5y ago
    :-) 640x480, also known as God's preferred resolution: https://en.wikipedia.org/w/index.php?title=TempleOS&oldid=1057407249#System_overview https://en.wikipedia.org/w/index.php?title=TempleOS&oldid=10...
  - akkartik 5y ago
    Yeah, this was definitely a concern for me when building Mu. What do you think of the one font Mu has? It's http://unifoundry.com/unifont http://unifoundry.com/unifont. I was trying to get to some minimum level of legibility while otherwise optimizing for simplicity. 1024x768 seemed like a reasonable compromise, though adjacent resolutions are also fine.
    - andai 5y ago
      I like that font: I once saw it in a screenshot and spent a good amount of time trying to figure out which font it was.
    - yorwba 5y ago
      Note the limitations section: > Unifont Limitations > Unifont only stores one glyph per printable Unicode code point. This means that complex scripts with special forms for letter combinations including consonant combinations and floating vowel marks such as with Indic scripts (Devanagari, Bengali, Tamil, etc.) or letters that change shape depending upon their position in a word (Indic and Arabic scripts) will not render well in Unifont. In those cases, Unifont is only suitable as a font of last resort. Users wishing to properly render such complex scripts should use full OpenType fonts that faithfully display such alternate forms. So if your intention when choosing unifont was to support all of Unicode, it would be good to make it not too difficult to add more fonts.
      - akkartik 5y ago
        I definitely prioritize supporting all languages. (I don't care about flags and emoji and crap like that.) However I don't know enough yet. The current list of supported languages is enumerated at http://akkartik.github.io/mu/html/103glyph.subx.html#L98 http://akkartik.github.io/mu/html/103glyph.subx.html#L98 It's not just a matter of supporting more fonts. I need to support smarter fonts with ligatures and more. I think we could preserve the constraint of a single font and just make it smarter. But it'll take me some time to learn enough to do that.
        yorwba 5y ago
        Yeah, ligatures are required for many languages. E.g. you list Myanmar, where it's possible to construct something like င်္င္င္င္ငြေေေေေေေောာာာာာာာ, which has "nga" င, "asat" ်, "virama" ္ combined to put င်္ on the following consonant, which in this case is four "nga" င separated by three "virama" ္ to form a cluster င္င္င္င (Noto Sans Myanmar apparently supports stacking up to height 3, the fourth "nga" င awkwardly overlaps), then there's a "medial ra" ြ which puts a box around the preceding consonant without overlapping, then 8 copies of "e" ေ which should be rendered to the left of the consonant it follows and then 8 copies of "aa" ာ which attach to the right. You're not going to encounter something crazy like this in the wild (in Burmese, there's at most one of each vowel sign on a consonant, and I don't think stacking four consonants is ever necessary) but it serves as a demonstration of the edge cases that a font needs to handle. The lookup tables end up getting quite large, which I think is one of the reasons Noto isn't usually used as one file with all scripts.
    - magios 5y ago
      I actually use a slightly modified unifont exclusively on a linux system, deleted all other fonts, disabled browser font downloading, and use firefox to get proper rendering. If you use a tiling wm, without borders or spaces between windows, then three windows of 80 columns of 8x16 font works.
      - akkartik 5y ago
        Wow!
      - spicybright 5y ago
        I've never heard of deleting all fonts before, but I supposed that would work well for what you're going for! Wish general computing was more customizable like that...
      - aethertron 5y ago
        I would love to see a screenshot!
        Shared404 5y ago
        Seconding this!
      - magios 5y ago
        sorry for the late reply, also forgot to mention that I use a fontconfig file, .xresources, other config files for i3 (the tiling wm), termimal (xst) and vim that specify the unifont font specifically. here are a few images showing the setup and sites using unifont. https://imgur.com/a/5gAZau3 https://imgur.com/a/5gAZau3
        aethertron 5y ago
        Cool. I'd probably pick a different font, but I like this consistency. Perhaps as a way resisting attempts at emotional manipulation by typography...
    - carapace 5y ago
      Unifont seems very useful. Not pretty but definitely legible. - - - - FWIW, I ran across this the other day: "4x4 ASCII Font" > Small fonts have always been fascinating to me, so I decided to make the smallest font possible, which turned out to be 4x4 pixels per character. The font covers the entire range of visible ASCII characters, and most are immediately recognizable. https://simplifier.neocities.org/4x4.html https://simplifier.neocities.org/4x4.html - - - - For display from small machines I keep going back and forth between simple memory-mapped raster screens vs. emitting a stream of, say, SVG to an external "display processor" (following the "Wheel of Reincarnation": "On the Design of Display Processors" http://cva.stanford.edu/classes/cs99s/papers/myer-sutherland-design-of-display-processors.pdf http://cva.stanford.edu/classes/cs99s/papers/myer-sutherland... )
      - selfhoster11 5y ago
        I'm actually fond of the Unifont letter shapes. It might be just that I'm used to this font from using Linux, but I actually like it.
      - ExtraE 5y ago
        In principle wouldn’t 3x3 be the theoretical limit? That’s 9 bits/char which is enough for twice ASCII.
    - selfhoster11 5y ago
      Unifont is perfectly fine. Linux uses it in various places, so I don't mind it. In fact, I rather like its letter shapes. 1024x768 is more than reasonable. Almost luxurious in a "small"/"personal" computing context, but in a good way. I still use computers with that resolution sometimes.
  - mdp2021 5y ago
    You can start with the C64 definition as a base and rewrite it expanding it (e.g. instead of 40x25 cells, 320x200 pixels on 1000 bytes pointing to 8x8 sized chars, you could provide a similarly working mode but 120x64 cells, 1920x1024 pixels on 7680 bytes pointing to 16x16 sized multicolor chars). Have four SID instead of one, 64 sprites, use a large number of switchable 64Kb regions as modules (and/or a huge disk in physical RAM) etc. You can just take inspiration from the original and see how the traditional ideas could be adapted for current hardware.
- klelatti 5y ago
  Colour Maximite seems like a practical piece of modern hardware that takes a similar approach to the classic 80s home computers. https://geoffg.net/maximite.html https://geoffg.net/maximite.html
  - spicybright 5y ago
    I love hacker news because I'm always finding interesting things like these :) Thank you for sharing!
- stephbu 5y ago
  Yes, it reminded me a lot of when I first started in computing. Today we are so abstracted from the horsepower that produces our experiences, to the extent that most Software Engineers don't actually know how their code works. Not saying that is a bad thing, not saying that it is mandatory, it's just an art and science that is eroding rapidly. I started as an 8yr old, reading computer magazines, and initially coding in BASIC in 1K of RAM. I into Z80 Assembler and Machine Code at 10yrs - learning primitives like NMI's, Display DMA and Sound IO by hand with pencil, paper, and lots of reboot-causing mistakes. It was bruteforce, but still very influential in my understanding of a then-modern computer system. Z80 was a simple-enough chip instruction set that I still remember most the mnemonics today, and many of the architectural principals are still valid even after so much time.
  - fwip 5y ago
    > most Software Engineers don't actually know how their code works. This is only true when you decide that the specific level of abstraction that you learned is the important one. Sure, you knew the machine code. Did you know how the instruction set was implemented on the chip? The decode logic at a transistor logic to set the right signals to route your register to the ALU? Did you care about the equations that governed the flow of electrons through silicon? Or did you trust the machine code to be your level of abstraction that Worked?
    - AnIdiotOnTheNet 5y ago
      The world isn't as black and white as "all abstractions bad" or "all abstractions good" though. There are levels of abstraction that are objectively useful and levels of abstraction that are so separated from reality that a 3Ghz multicore computer is somehow incapable of keeping up with a human's typed input.
      - fwip 5y ago
        And the level of abstraction that is "good" changes over time and by use case. At my day job, I write both high-performance bioinformatics software and good-enough-performance web software. I do need to look at the assembly & think about the internals of the CPU when I'm trying to push through billions of reads in a timely manner. But I don't need to count cycles when I'm rendering a CRUD detail page in Django - I just need to make sure my database queries are reasonable. Also, the idea that you can say some abstractions (presumably in wide use) are "objectively" bad only makes sense if you've already applied your subjective criteria.
Stampo00 5y ago
See also uxn, uxntal, and varvara, which I feel have similar design goals. I love this movement. I miss personal computing. https://wiki.xxiivv.com/site/uxn.html https://wiki.xxiivv.com/site/uxn.html https://wiki.xxiivv.com/site/uxntal.html https://wiki.xxiivv.com/site/uxntal.html https://wiki.xxiivv.com/site/varvara.html https://wiki.xxiivv.com/site/varvara.html
- nemo1618 5y ago
  And Urbit, of course! https://urbit.org https://urbit.org
  - VikingCoder 5y ago
    Thanks for sharing Urbit, it's super interesting... ...and it's also awful. I get sad when I see an idea that I like implemented to poorly. It sucks oxygen out of the room, or poisons the well, or whatever. I think I basically want Deno with a decentralized ID / DNS system that has nothing to do with the hierarchy or Urbit... And using capability modeling for different apps... And with something like Wire Guard for end-to-end encryption... That feels like a federated version of Sandstorm.io... That's what I'm daydreaming about.
  - still_grokking 5y ago
    Let's see… https://github.com/urbit/urbit/blob/master/pkg/arvo/sys/arvo.hoon https://github.com/urbit/urbit/blob/master/pkg/arvo/sys/arvo... This is a kind of joke, isn't it?
VikingCoder 5y ago
Has anyone gotten DCPU-16 [1] to run directly on hardware? [1]: https://en.wikipedia.org/wiki/0x10c https://en.wikipedia.org/wiki/0x10c
bvrmn 5y ago
Some generic registers (r1, r2...) would be easy to implement and allocate on translation step.
- akkartik 5y ago
  Perhaps I should rename the registers to generic r1-r6. The trouble with automatically allocating registers is that you sometimes need to spill. And that means instructions need to work with either registers or memory. That feels like a very different kind of language, closer to C. You lose the largely 1:1 mapping with machine code that I was aiming for. Code generation gets more complex -- and my whole goal was to implement it in unsafe machine code (the SubX notation) and avoid metacircularity. Instead Mu makes you allocate registers -- but verifies your allocation so you have a reasonably decent experience.
  - nyanpasu64 5y ago
    I want a software stack an application developer (me) can fully understand. I don't want it to depend on a heavy opaque runtime obscuring control flow, requiring both native and VM-level debuggers, and resulting in unpredictable performance (Java/C#/JS). I don't want it to rely on GPU APIs, which expose hardware and driver implementation details (making software behave differently on different computers, and even malfunction on some hardware or with the wrong drivers installed), and lose support on newer hardware (you can't play Touhou 6 without a DX8 emulator). I don't want deep dependencies on heavyweight OSes and daemons and IPC (D-Bus desktop portals and drag-and-drop keep malfunctioning, playing Touhou or running Japanese software requires juggling Windows app locale emulators). I don't want heavyweight apps built on thick GUI frameworks or sprawling OS APIs, resulting in apps which can't run on OSes 10 years in the future (since they're missing GTK2 or Qt4 or WPF, or have an incompatible libstdc++), and also can't run on bare-metal emulators unless you install the full OS. Maybe Mu is it. I don't know. My concern is that low level code with manual register allocations is too unproductive, and even C (not to mention C++ or Rust) is complex enough that I don't know what the compiler is doing at -O2, with or without TBAA, with or without restrict, etc. Is it even possible to get a small understandable stack, and full Unicode support, OS-like text editing and keyboard shortcuts, system fonts, system font rendering and fontconfig, tab navigation to jump between widgets, maybe even OS file dialogs and accessibility? Lagrange is a Gemini client which depends on not much more than SDL (good), but doesn't use OS fonts rendering and text editing (bad).
thingification 5y ago
From my skim of the README this sounds like (in part) a system for generating unikernels, is that correct? Would anybody like to compare/contrast this with https://mirage.io/ https://mirage.io/?
- akkartik 5y ago
  I was certainly aware of unikernels (on a pretty superficial level) when I started Mu. A shared goal is minimizing attack surface. However, Mu also has a second goal: minimizing the build time supply chain and making it more auditable. There Mu has more in common with http://bootstrappable.org http://bootstrappable.org which is building https://www.gnu.org/software/mes https://www.gnu.org/software/mes. In service of this goal I've ended up leaving all C behind. As I understand it, unikernels want to let you bring your own application sources, and try to compile it to their substrate. Mu requires you to build your application for it. There's no compatibility with anything beyond the x86 instruction set (and Unicode).
dang 5y ago
One past thread: Mu: A Human Scale Computer - https://news.ycombinator.com/item?id=21242190 https://news.ycombinator.com/item?id=21242190 - Oct 2019 (12 comments)
akkartik 5y ago
If you're interested in playing with Mu, there's a guided tour where I try to make the process as painless as possible: https://github.com/akkartik/mu/blob/main/tutorial/index.md https://github.com/akkartik/mu/blob/main/tutorial/index.md
monocasa 5y ago
That's real neat. It sort of reminds me of the high level goals of TempleOS. Pining for the days of earlyish microcomputers where you truly owned and could understand the software stack sitting in front of you on your desk.
marcodiego 5y ago
Suppose someone plans to create a multitasking OS for a z80 based computer lacking memory protection. With the goal of saving memory and to guarantee memory isolation between processes, it is decided that the OS would actually be a byte-code interpreter capable of running multiple programs at the same time. So, a byte-code must be chosen to the project. Brainfuck is considered at first: it is extremely simple to implement but is rejected because has very little code density. Then, Chip-8 is considered: it is simple to implement and there are many programs and tools already available. Then p-code is looked at, but it is nowhere near as popular as Chip-8 and apparently not as simple to implement. Other vm's are considered but are rejected because they are not simple or not very popular: SWEET16, ijvm and tinybasic. Now, what is a good choice for such a situation? What is a good byte-code for such an endeavor? Restrictions are: 64kb of RAM not counting graphics or overlays for drivers that can be dynamically loaded, possibility of running 3 to 10 tasks at the same time, with a good balance of code density and performance, easy to implement and possibly with available tools or good example programs?
- akkartik 5y ago
  Have you looked into CollapseOS? It might fit your criteria if you're willing to put up with cooperative multitasking. http://collapseos.org http://collapseos.org
- AnIdiotOnTheNet 5y ago
  I've thought along similar lines a lot recently, and I think you end up wanting something like WASM, but without all the design-by-committee that comes with that. Specifically, ditch the parametric instructions, add arbitrary bit-width ints, multiple memories, a way to allocate and free memories, and hints[0]; and make the binary format simpler to parse by removing the completely unnecessary integer compression. [0] by which I mean the ability to tag functions and variables with an indication of what they're used for so the interpreter/jit is able to replace them with an efficient implementation if one is known to it. For instance, you possibly don't even need float types, just have routines for doing soft-float arithmetic tagged such that the interpreter knows they implement IEEE floating point operations that the processor may be able to handle on its own.
- 5y ago

152 points by finite_jest 5y ago

I feel like the idea could be covered by commodore 64. Even adding basic networking in any way opens up an absolutely massive amount of un-abstracted concepts and processes to keep in one head. That said I flippin love people re-inventing a computer into something not derived from a VAX timeshare machine from the 70s.

selfhoster11 5y ago
The main issue with older machines is that the resolution isn't great for writing. I like reasonable letter shapes, and you kind of need 640x480 for that at least.
- finite_jest 5y ago
  :-) 640x480, also known as God's preferred resolution: https://en.wikipedia.org/w/index.php?title=TempleOS&oldid=1057407249#System_overview https://en.wikipedia.org/w/index.php?title=TempleOS&oldid=10...
- akkartik 5y ago
  Yeah, this was definitely a concern for me when building Mu. What do you think of the one font Mu has? It's http://unifoundry.com/unifont http://unifoundry.com/unifont. I was trying to get to some minimum level of legibility while otherwise optimizing for simplicity. 1024x768 seemed like a reasonable compromise, though adjacent resolutions are also fine.
  - andai 5y ago
    I like that font: I once saw it in a screenshot and spent a good amount of time trying to figure out which font it was.
  - yorwba 5y ago
    Note the limitations section: > Unifont Limitations > Unifont only stores one glyph per printable Unicode code point. This means that complex scripts with special forms for letter combinations including consonant combinations and floating vowel marks such as with Indic scripts (Devanagari, Bengali, Tamil, etc.) or letters that change shape depending upon their position in a word (Indic and Arabic scripts) will not render well in Unifont. In those cases, Unifont is only suitable as a font of last resort. Users wishing to properly render such complex scripts should use full OpenType fonts that faithfully display such alternate forms. So if your intention when choosing unifont was to support all of Unicode, it would be good to make it not too difficult to add more fonts.
    - akkartik 5y ago
      I definitely prioritize supporting all languages. (I don't care about flags and emoji and crap like that.) However I don't know enough yet. The current list of supported languages is enumerated at http://akkartik.github.io/mu/html/103glyph.subx.html#L98 http://akkartik.github.io/mu/html/103glyph.subx.html#L98 It's not just a matter of supporting more fonts. I need to support smarter fonts with ligatures and more. I think we could preserve the constraint of a single font and just make it smarter. But it'll take me some time to learn enough to do that.
      - yorwba 5y ago
        Yeah, ligatures are required for many languages. E.g. you list Myanmar, where it's possible to construct something like င်္င္င္င္ငြေေေေေေေောာာာာာာာ, which has "nga" င, "asat" ်, "virama" ္ combined to put င်္ on the following consonant, which in this case is four "nga" င separated by three "virama" ္ to form a cluster င္င္င္င (Noto Sans Myanmar apparently supports stacking up to height 3, the fourth "nga" င awkwardly overlaps), then there's a "medial ra" ြ which puts a box around the preceding consonant without overlapping, then 8 copies of "e" ေ which should be rendered to the left of the consonant it follows and then 8 copies of "aa" ာ which attach to the right. You're not going to encounter something crazy like this in the wild (in Burmese, there's at most one of each vowel sign on a consonant, and I don't think stacking four consonants is ever necessary) but it serves as a demonstration of the edge cases that a font needs to handle. The lookup tables end up getting quite large, which I think is one of the reasons Noto isn't usually used as one file with all scripts.
  - magios 5y ago
    I actually use a slightly modified unifont exclusively on a linux system, deleted all other fonts, disabled browser font downloading, and use firefox to get proper rendering. If you use a tiling wm, without borders or spaces between windows, then three windows of 80 columns of 8x16 font works.
    - akkartik 5y ago
      Wow!
    - spicybright 5y ago
      I've never heard of deleting all fonts before, but I supposed that would work well for what you're going for! Wish general computing was more customizable like that...
    - aethertron 5y ago
      I would love to see a screenshot!
      - Shared404 5y ago
        Seconding this!
    - magios 5y ago
      sorry for the late reply, also forgot to mention that I use a fontconfig file, .xresources, other config files for i3 (the tiling wm), termimal (xst) and vim that specify the unifont font specifically. here are a few images showing the setup and sites using unifont. https://imgur.com/a/5gAZau3 https://imgur.com/a/5gAZau3
      - aethertron 5y ago
        Cool. I'd probably pick a different font, but I like this consistency. Perhaps as a way resisting attempts at emotional manipulation by typography...
  - carapace 5y ago
    Unifont seems very useful. Not pretty but definitely legible. - - - - FWIW, I ran across this the other day: "4x4 ASCII Font" > Small fonts have always been fascinating to me, so I decided to make the smallest font possible, which turned out to be 4x4 pixels per character. The font covers the entire range of visible ASCII characters, and most are immediately recognizable. https://simplifier.neocities.org/4x4.html https://simplifier.neocities.org/4x4.html - - - - For display from small machines I keep going back and forth between simple memory-mapped raster screens vs. emitting a stream of, say, SVG to an external "display processor" (following the "Wheel of Reincarnation": "On the Design of Display Processors" http://cva.stanford.edu/classes/cs99s/papers/myer-sutherland-design-of-display-processors.pdf http://cva.stanford.edu/classes/cs99s/papers/myer-sutherland... )
    - selfhoster11 5y ago
      I'm actually fond of the Unifont letter shapes. It might be just that I'm used to this font from using Linux, but I actually like it.
    - ExtraE 5y ago
      In principle wouldn’t 3x3 be the theoretical limit? That’s 9 bits/char which is enough for twice ASCII.
  - selfhoster11 5y ago
    Unifont is perfectly fine. Linux uses it in various places, so I don't mind it. In fact, I rather like its letter shapes. 1024x768 is more than reasonable. Almost luxurious in a "small"/"personal" computing context, but in a good way. I still use computers with that resolution sometimes.
- mdp2021 5y ago
  You can start with the C64 definition as a base and rewrite it expanding it (e.g. instead of 40x25 cells, 320x200 pixels on 1000 bytes pointing to 8x8 sized chars, you could provide a similarly working mode but 120x64 cells, 1920x1024 pixels on 7680 bytes pointing to 16x16 sized multicolor chars). Have four SID instead of one, 64 sprites, use a large number of switchable 64Kb regions as modules (and/or a huge disk in physical RAM) etc. You can just take inspiration from the original and see how the traditional ideas could be adapted for current hardware.
klelatti 5y ago
Colour Maximite seems like a practical piece of modern hardware that takes a similar approach to the classic 80s home computers. https://geoffg.net/maximite.html https://geoffg.net/maximite.html
- spicybright 5y ago
  I love hacker news because I'm always finding interesting things like these :) Thank you for sharing!
stephbu 5y ago
Yes, it reminded me a lot of when I first started in computing. Today we are so abstracted from the horsepower that produces our experiences, to the extent that most Software Engineers don't actually know how their code works. Not saying that is a bad thing, not saying that it is mandatory, it's just an art and science that is eroding rapidly. I started as an 8yr old, reading computer magazines, and initially coding in BASIC in 1K of RAM. I into Z80 Assembler and Machine Code at 10yrs - learning primitives like NMI's, Display DMA and Sound IO by hand with pencil, paper, and lots of reboot-causing mistakes. It was bruteforce, but still very influential in my understanding of a then-modern computer system. Z80 was a simple-enough chip instruction set that I still remember most the mnemonics today, and many of the architectural principals are still valid even after so much time.
- fwip 5y ago
  > most Software Engineers don't actually know how their code works. This is only true when you decide that the specific level of abstraction that you learned is the important one. Sure, you knew the machine code. Did you know how the instruction set was implemented on the chip? The decode logic at a transistor logic to set the right signals to route your register to the ALU? Did you care about the equations that governed the flow of electrons through silicon? Or did you trust the machine code to be your level of abstraction that Worked?
  - AnIdiotOnTheNet 5y ago
    The world isn't as black and white as "all abstractions bad" or "all abstractions good" though. There are levels of abstraction that are objectively useful and levels of abstraction that are so separated from reality that a 3Ghz multicore computer is somehow incapable of keeping up with a human's typed input.
    - fwip 5y ago
      And the level of abstraction that is "good" changes over time and by use case. At my day job, I write both high-performance bioinformatics software and good-enough-performance web software. I do need to look at the assembly & think about the internals of the CPU when I'm trying to push through billions of reads in a timely manner. But I don't need to count cycles when I'm rendering a CRUD detail page in Django - I just need to make sure my database queries are reasonable. Also, the idea that you can say some abstractions (presumably in wide use) are "objectively" bad only makes sense if you've already applied your subjective criteria.

Stampo00 5y ago

See also uxn, uxntal, and varvara, which I feel have similar design goals. I love this movement. I miss personal computing. https://wiki.xxiivv.com/site/uxn.html https://wiki.xxiivv.com/site/uxn.html https://wiki.xxiivv.com/site/uxntal.html https://wiki.xxiivv.com/site/uxntal.html https://wiki.xxiivv.com/site/varvara.html https://wiki.xxiivv.com/site/varvara.html

nemo1618 5y ago
And Urbit, of course! https://urbit.org https://urbit.org
- VikingCoder 5y ago
  Thanks for sharing Urbit, it's super interesting... ...and it's also awful. I get sad when I see an idea that I like implemented to poorly. It sucks oxygen out of the room, or poisons the well, or whatever. I think I basically want Deno with a decentralized ID / DNS system that has nothing to do with the hierarchy or Urbit... And using capability modeling for different apps... And with something like Wire Guard for end-to-end encryption... That feels like a federated version of Sandstorm.io... That's what I'm daydreaming about.
- still_grokking 5y ago
  Let's see… https://github.com/urbit/urbit/blob/master/pkg/arvo/sys/arvo.hoon https://github.com/urbit/urbit/blob/master/pkg/arvo/sys/arvo... This is a kind of joke, isn't it?

VikingCoder 5y ago

Has anyone gotten DCPU-16 [1] to run directly on hardware? [1]: https://en.wikipedia.org/wiki/0x10c https://en.wikipedia.org/wiki/0x10c

bvrmn 5y ago

Some generic registers (r1, r2...) would be easy to implement and allocate on translation step.

akkartik 5y ago
Perhaps I should rename the registers to generic r1-r6. The trouble with automatically allocating registers is that you sometimes need to spill. And that means instructions need to work with either registers or memory. That feels like a very different kind of language, closer to C. You lose the largely 1:1 mapping with machine code that I was aiming for. Code generation gets more complex -- and my whole goal was to implement it in unsafe machine code (the SubX notation) and avoid metacircularity. Instead Mu makes you allocate registers -- but verifies your allocation so you have a reasonably decent experience.
- nyanpasu64 5y ago
  I want a software stack an application developer (me) can fully understand. I don't want it to depend on a heavy opaque runtime obscuring control flow, requiring both native and VM-level debuggers, and resulting in unpredictable performance (Java/C#/JS). I don't want it to rely on GPU APIs, which expose hardware and driver implementation details (making software behave differently on different computers, and even malfunction on some hardware or with the wrong drivers installed), and lose support on newer hardware (you can't play Touhou 6 without a DX8 emulator). I don't want deep dependencies on heavyweight OSes and daemons and IPC (D-Bus desktop portals and drag-and-drop keep malfunctioning, playing Touhou or running Japanese software requires juggling Windows app locale emulators). I don't want heavyweight apps built on thick GUI frameworks or sprawling OS APIs, resulting in apps which can't run on OSes 10 years in the future (since they're missing GTK2 or Qt4 or WPF, or have an incompatible libstdc++), and also can't run on bare-metal emulators unless you install the full OS. Maybe Mu is it. I don't know. My concern is that low level code with manual register allocations is too unproductive, and even C (not to mention C++ or Rust) is complex enough that I don't know what the compiler is doing at -O2, with or without TBAA, with or without restrict, etc. Is it even possible to get a small understandable stack, and full Unicode support, OS-like text editing and keyboard shortcuts, system fonts, system font rendering and fontconfig, tab navigation to jump between widgets, maybe even OS file dialogs and accessibility? Lagrange is a Gemini client which depends on not much more than SDL (good), but doesn't use OS fonts rendering and text editing (bad).

thingification 5y ago

From my skim of the README this sounds like (in part) a system for generating unikernels, is that correct? Would anybody like to compare/contrast this with https://mirage.io/ https://mirage.io/?

akkartik 5y ago
I was certainly aware of unikernels (on a pretty superficial level) when I started Mu. A shared goal is minimizing attack surface. However, Mu also has a second goal: minimizing the build time supply chain and making it more auditable. There Mu has more in common with http://bootstrappable.org http://bootstrappable.org which is building https://www.gnu.org/software/mes https://www.gnu.org/software/mes. In service of this goal I've ended up leaving all C behind. As I understand it, unikernels want to let you bring your own application sources, and try to compile it to their substrate. Mu requires you to build your application for it. There's no compatibility with anything beyond the x86 instruction set (and Unicode).

dang 5y ago

One past thread: Mu: A Human Scale Computer - https://news.ycombinator.com/item?id=21242190 https://news.ycombinator.com/item?id=21242190 - Oct 2019 (12 comments)

akkartik 5y ago

If you're interested in playing with Mu, there's a guided tour where I try to make the process as painless as possible: https://github.com/akkartik/mu/blob/main/tutorial/index.md https://github.com/akkartik/mu/blob/main/tutorial/index.md

monocasa 5y ago

That's real neat. It sort of reminds me of the high level goals of TempleOS. Pining for the days of earlyish microcomputers where you truly owned and could understand the software stack sitting in front of you on your desk.

marcodiego 5y ago

Suppose someone plans to create a multitasking OS for a z80 based computer lacking memory protection. With the goal of saving memory and to guarantee memory isolation between processes, it is decided that the OS would actually be a byte-code interpreter capable of running multiple programs at the same time. So, a byte-code must be chosen to the project. Brainfuck is considered at first: it is extremely simple to implement but is rejected because has very little code density. Then, Chip-8 is considered: it is simple to implement and there are many programs and tools already available. Then p-code is looked at, but it is nowhere near as popular as Chip-8 and apparently not as simple to implement. Other vm's are considered but are rejected because they are not simple or not very popular: SWEET16, ijvm and tinybasic. Now, what is a good choice for such a situation? What is a good byte-code for such an endeavor? Restrictions are: 64kb of RAM not counting graphics or overlays for drivers that can be dynamically loaded, possibility of running 3 to 10 tasks at the same time, with a good balance of code density and performance, easy to implement and possibly with available tools or good example programs?

akkartik 5y ago
Have you looked into CollapseOS? It might fit your criteria if you're willing to put up with cooperative multitasking. http://collapseos.org http://collapseos.org
AnIdiotOnTheNet 5y ago
I've thought along similar lines a lot recently, and I think you end up wanting something like WASM, but without all the design-by-committee that comes with that. Specifically, ditch the parametric instructions, add arbitrary bit-width ints, multiple memories, a way to allocate and free memories, and hints[0]; and make the binary format simpler to parse by removing the completely unnecessary integer compression. [0] by which I mean the ability to tag functions and variables with an indication of what they're used for so the interpreter/jit is able to replace them with an efficient implementation if one is known to it. For instance, you possibly don't even need float types, just have routines for doing soft-float arithmetic tagged such that the interpreter knows they implement IEEE floating point operations that the processor may be able to handle on its own.
5y ago