Javascript virtual machine is one instruction set machine to parse and execute an assembly like code.
JSVM
github.com
JSVM
1–10 of 17 posts
Re: JSVM
#2I love low-level learning projects like this, but I wish more of them would centralize around something like Nand2Tetris[1] to create an expanded, and interconnected, learning ecosystem.
Re: JSVM
#3Shameless plug: a while back I wrote an assembler-and-VM for a similarly hypothetical assembly language that I was studying in class. Just for kicks, I wondered if I could fit the entire thing into 1KB of JavaScript, whilst including features as step by step execution, a "debugging GUI" (as much as you could expect from 1KB!) featuring the stack, register contents and program counter, plus the assembler on top which performs full syntax/opcode argument checking.
The result (which I'm pretty pleased with) is here: http://chengsun.github.io/ocremutiny.html
Re: JSVM
#4If I make make a few suggestions (mostly from a desire to see a more familiar sort of spec):
> Add arithmetic shift left/right
> Add logical shift left/right
> Add exclusive OR (XOR)
> Pick a word size so your integer and bit ops have meaning
Questions:
> How do I set the program counter from my assembly?
> Do I have registers (seems like a stack-based VM, so no)? If not, can I have more stacks?
> Can you setup a dedicated block of memory to use as a framebuffer and render it to a tag?
~
Good work so far!
Re: JSVM
#5I had to write one of these (in C) for a class a couple years ago.
Re: JSVM
#6I had to write one of these (in C) for a class a couple years ago. https://github.com/tylerkahn/MIPS-Virtual-Machine
Yay MIPS!
Also, let us not forget the Halt and Spontaneously Combust (HSC) instruction: ftp://reports.stanford.edu/pub/cstr/reports/csl/tr/86/289/CSL-TR-86-289.pdf .
Re: JSVM
#7I had to write one of these (in C) for a class a couple years ago. https://github.com/tylerkahn/MIPS-Virtual-Machine
Whoa dude, this is awesome!
I once wrote a MIPS assembler+VM in Racket. It went OK but I never used it for anything: https://github.com/gcr/mips-simulator Was a great learning experience though.
Re: JSVM
#8Better name it VM.js !!
Re: JSVM
#9Better name it VM.js !!
I real disappointed when I discovered this was not an amateur JS vm that I could read in a weekend or two, that would be awesome to have :(
Re: JSVM
#10Your VM will work much faster if you take the time to do a second pass over the generated "code" and resolve the jumps to LABELs all at once instead of linearly scanning the code for the appropriate target on each jump.