3 ms·

Interesting. Only somewhat related; any pointers to articles/document on implementing a stack-based virtual machine?

bugfix-66 4y ago
Look at the Green Arrays F18, the "conclusion" that Forth reached: https://www.greenarraychips.com/home/documents/greg/PB003-110412-F18A.pdf https://www.greenarraychips.com/home/documents/greg/PB003-11... Here's a clear description of what each instruction does: https://colorforth.github.io/forth.html https://colorforth.github.io/forth.html Hilariously, the system has no logical OR, only AND and XOR and NOT, because "Inclusive-or is rarely needed." This system was designed by Chuck Moore, father of Forth. Here is an entertaining video of him explaining the F18A stack machine and programming system: https://youtu.be/0PclgBd6_Zs https://youtu.be/0PclgBd6_Zs This is such a simple machine. I am planning to make a tiny emulator for my site. One could probably write an emulator in 80 lines of Go (one goroutine for each of the 144 cores).
- whatshisface 4y ago
  >The word */ multiplies by a ratio, with a double-length intermediate product. It eliminates the need for floating-point. Anyone who knows a lot about numeric stuff care to comment on this statement?
  - bugfix-66 4y ago
    It's just a fixed point instruction. Fixed point multiply: a*m times b*m yields (a*b)*m = a*m * b*m / m In the above, m is the fixed point 1. For example, 65536 for a 16.16 fixed point. The instruction allows you to multiply a*m by b*m and then divide by m, renormalizing your fixed point result. Chuck Moore thinks nobody needs floating point because fixed point is sufficient!
    - Someone 4y ago
      And, importantly, the double-length intermediate result prevents the rapid loss of precision, compared to the naive alternatives of : */ * 65536 / : and : */ 65536 / * ;
spaintech 4y ago
This might have what you need… https://wiki.xxiivv.com/site/uxn.html https://wiki.xxiivv.com/site/uxn.html interesting design and fun little project.
entaloneralie 4y ago
This talk covers some of the design decisions that lead to the design of the uxn stack machine. https://vimeo.com/771406693#t=85m30s https://vimeo.com/771406693#t=85m30s C source code of the VM, 100 lines. https://git.sr.ht/~rabbits/uxn/tree/main/item/src/uxn.c https://git.sr.ht/~rabbits/uxn/tree/main/item/src/uxn.c An example assembly file for that stack machine https://git.sr.ht/~rabbits/uxn/tree/main/item/projects/examples/exercises/fib.tal https://git.sr.ht/~rabbits/uxn/tree/main/item/projects/examp... Another stack machine designed to target FPGA with an elegant design, mentioned in the talk above. https://excamera.com/sphinx/article-j1a-swapforth.html https://excamera.com/sphinx/article-j1a-swapforth.html
bmitc 4y ago
The virtual machine in nand2tetris (book is *The Elements of Computing Systems) is stack-based. https://www.nand2tetris.org/ https://www.nand2tetris.org/ https://mitpress.mit.edu/9780262539807/the-elements-of-computing-systems/ https://mitpress.mit.edu/9780262539807/the-elements-of-compu... https://www.coursera.org/learn/build-a-computer https://www.coursera.org/learn/build-a-computer
LAC-Tech 4y ago
Chapter 3 of this book is pretty useful for that, as each of the instructions have pseudo code descriptions. Worth noting they only pop once for the ADD instruction, not twice!
gjadi 4y ago
What about the JVM? :D https://docs.oracle.com/javase/specs/jvms/se7/html/index.html https://docs.oracle.com/javase/specs/jvms/se7/html/index.htm...

Look at the Green Arrays F18, the "conclusion" that Forth reached: https://www.greenarraychips.com/home/documents/greg/PB003-110412-F18A.pdf https://www.greenarraychips.com/home/documents/greg/PB003-11... Here's a clear description of what each instruction does: https://colorforth.github.io/forth.html https://colorforth.github.io/forth.html Hilariously, the system has no logical OR, only AND and XOR and NOT, because "Inclusive-or is rarely needed." This system was designed by Chuck Moore, father of Forth. Here is an entertaining video of him explaining the F18A stack machine and programming system: https://youtu.be/0PclgBd6_Zs https://youtu.be/0PclgBd6_Zs This is such a simple machine. I am planning to make a tiny emulator for my site. One could probably write an emulator in 80 lines of Go (one goroutine for each of the 144 cores).

whatshisface 4y ago
>The word */ multiplies by a ratio, with a double-length intermediate product. It eliminates the need for floating-point. Anyone who knows a lot about numeric stuff care to comment on this statement?
- bugfix-66 4y ago
  It's just a fixed point instruction. Fixed point multiply: a*m times b*m yields (a*b)*m = a*m * b*m / m In the above, m is the fixed point 1. For example, 65536 for a 16.16 fixed point. The instruction allows you to multiply a*m by b*m and then divide by m, renormalizing your fixed point result. Chuck Moore thinks nobody needs floating point because fixed point is sufficient!
  - Someone 4y ago
    And, importantly, the double-length intermediate result prevents the rapid loss of precision, compared to the naive alternatives of : */ * 65536 / : and : */ 65536 / * ;

spaintech 4y ago

This might have what you need… https://wiki.xxiivv.com/site/uxn.html https://wiki.xxiivv.com/site/uxn.html interesting design and fun little project.

entaloneralie 4y ago

This talk covers some of the design decisions that lead to the design of the uxn stack machine. https://vimeo.com/771406693#t=85m30s https://vimeo.com/771406693#t=85m30s C source code of the VM, 100 lines. https://git.sr.ht/~rabbits/uxn/tree/main/item/src/uxn.c https://git.sr.ht/~rabbits/uxn/tree/main/item/src/uxn.c An example assembly file for that stack machine https://git.sr.ht/~rabbits/uxn/tree/main/item/projects/examples/exercises/fib.tal https://git.sr.ht/~rabbits/uxn/tree/main/item/projects/examp... Another stack machine designed to target FPGA with an elegant design, mentioned in the talk above. https://excamera.com/sphinx/article-j1a-swapforth.html https://excamera.com/sphinx/article-j1a-swapforth.html

bmitc 4y ago

The virtual machine in nand2tetris (book is *The Elements of Computing Systems) is stack-based. https://www.nand2tetris.org/ https://www.nand2tetris.org/ https://mitpress.mit.edu/9780262539807/the-elements-of-computing-systems/ https://mitpress.mit.edu/9780262539807/the-elements-of-compu... https://www.coursera.org/learn/build-a-computer https://www.coursera.org/learn/build-a-computer

LAC-Tech 4y ago

Chapter 3 of this book is pretty useful for that, as each of the instructions have pseudo code descriptions. Worth noting they only pop once for the ADD instruction, not twice!

gjadi 4y ago

What about the JVM? :D https://docs.oracle.com/javase/specs/jvms/se7/html/index.html https://docs.oracle.com/javase/specs/jvms/se7/html/index.htm...