Python-based implementation of Notch's DCPU-16

https://github.com/jtauber/dcpu16py

by jtauber • 14 years ago

112 68 14 years ago

github.com

mahmud2• 14 years ago

this one is one of the more complete ones: has a disassembler. should be trivial to add stepping and breakpoints.

dbh937• 14 years ago

There should just be one thread for all the dcpu-16 implementations

look_lookatme• 14 years ago

What is a good resource for understanding how all of this works? Books, site, tutorial, minix usenet threads... I don't care, just something to get me started.

edit:

Assuming I'm a standard, competent web dev-ish Ruby, Python programmer with little experience below those languages.

jlawer5• 14 years ago

Your best bet is a university text book on computer architecture. The course I took used a decimal based CPU (not binary) and had many other "simplifications" but its probably your best bet, at least unless you want to learn assembly level programming full stop... in which case there is some really good 32bit linux asm tutorials out there (64 bit stuff isn't as common).

This is basically part of most first year IT / CS courses, and kind of not used in day to day IT so many self taught programmers never learn it.

jtauber7• 14 years ago

I'm actually planning on writing some tutorials based around DCPU-16 as it's a nice small instruction set with very orthogonal addressing modes (but don't worry if you don't know what that means :-)

Sort of a "Assembly Language for Python programmers" guide

patrickod2• 14 years ago

I would absolutely love to read this when it's done. Having never officially studied any of this I feel my knowledge is really lacking.

hendzen4• 14 years ago

First read K&R C and get comfortable writing C programs. Then pick up the latest edition of Patterson & Hennessy and learn the MIPS ISA. It's a very simple instruction set that avoids most of the pedagogical distractions imposed by x86 or some other more complicated architecture.

tptacek• 14 years ago

Second Hennesy & Patterson. Read it 12 years ago, still remember it vividly; everything made more sense afterwards.

It's expensive though; you might do just as well with a used older edition.

A somewhat perverse alternative approach: get a book on how debuggers work (like "How Debuggers Work").

AdamTReineke• 14 years ago

Why the latest edition? We're using the 2nd edition (from 1998) in my computer architecture class this semester and it seems just fine. Even better was getting it off Half.com for <$10 after shipping.

Gring• 14 years ago

There are two books co-authored by Patterson and Hennessy. Which one do you mean? "Computer Architecture: A Quantitative Approach" or "Computer Organization and Design: the Hardware/Software Interface"?

jmpeax• 14 years ago

Waiting for a glsl implementation.

jlawer5• 14 years ago

I am fairly sure notch would have one... if he is planning on running this, then I am going to imagine that he is basically going to have massive farms of GPGPUs planned for doing this emulation.

jerf5• 14 years ago

You could try to run a simulation of branch-heavy code on your hardware optimized for branchless number crunching, but you're probably better off compiling the opcodes into something that you can then use to simulate branch-heavy code on your branch-heavy-code-optimized hardware.

binarycrusader• 14 years ago

For the love of pete; please put a copyright notice and license on your code!

Even if you want to use the same license as notch, you must explicitly specify that, otherwise, no one can really use your code.

guelo2• 14 years ago

Doesn't no copyright notice mean that it's in the public domain?

iamwil• 14 years ago

No. copyright is automatically applied when the work is created. You have to explicitly give more relaxed rights, aka licenses and copylefts, for people to know whether they can use it.

eridius• 14 years ago

No. Copyright is implicit. Something can only be in the Public Domain if it's explicitly placed there (and supposedly, not all countries even recognize Public Domain, hence the creation of the WTFPL[1]).

[1] http://sam.zoy.org/wtfpl/

codezero• 14 years ago

Because most people adhere to copyright notices... Especially in this community.

jtauber7• 14 years ago

You must have just missed it. A LICENSE was added around the time you posted this comment.

anthonyb3• 14 years ago

That Cell class looks a bit odd, and I can't imagine it's doing good things for your memory use. Perhaps you could simplify it by making your registers a list or a dictionary, rather than a tuple?

ie.

  self.registers = { 'A': 0x0000, ... }

then you could access it directly:

  self.registers['A'] = 0x0001

jerf5• 14 years ago

Memory use isn't the problem, it's the added code complexity. Not having

   self.registers = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]

instead is adding ".value" all over the place where it isn't necessary. I haven't actually tried this but it looks like dropping the Cell class entirely, putting that line in as the definition of registers, then s/.values//g ought to work, or very nearly work.

PC, SP, and O are already defined as variables containing the index for that register, a fine way to do it.

anthonyb3• 14 years ago

Using the array module for registers and memory might be even better - you're not likely to want to randomly add a register or memory bank.

jtauber7• 14 years ago

The reason for the Cell() is explained in a comment; I have to be able to pass around references to registers and memory locations distinct from their value. I'm open to alternatives but the above won't work as how do you pass in "register A" or "memory location 0x1000" as the arg to an instruction method in that case?

severb• 14 years ago

Here's a Python asm compiler to go with those tools https://github.com/severb/0x10c-asm

coderdude• 14 years ago

This is so cool. Between jtauber's work and the other versions floating around I can't imagine that we won't be seeing basic compilers for higher level languages soon. So far there are emulators for the CPU, multiple assemblers, and a disassembler. Have you checked out the C version on the front page? He's been updating it like mad.

jtauber7• 14 years ago

Oh I hadn't seen this. I've actually implemented my own as part of dcpu16py.

krollew3• 14 years ago

I wonder why so many started to implement VMs for that processor. Just impatience when his next game will be released?

krasin• 14 years ago

implementing a VM is a game itself

krollew3• 14 years ago

There are so much things to implement. Why VM from game that is yet created?

praptak• 14 years ago

How did you decide which value of the PC to use (current instruction? next instruction? second word of current instruction?) when PC is one of the operands? The spec is not very clear on when exactly is PC incremented.

VMG• 14 years ago

I'd love to see a Haskell or Lisp implementation

clavalle• 14 years ago

Here you go:

https://docs.google.com/?pli=1#folders/0BxArLOveUH1bb081YWhD...

tzs• 14 years ago

Looks like implementing this thing is becoming the new national passtime, at least based on the number of different implementations that have been discussed on HN in the last day.

I wonder how long till someone implements it in minecraft?

overshard• 14 years ago

This is certainly the best implementation so far, clean, readable and actually works. Also allows for writing in ASM and not HEX with the assembler.

Python-based implementation of Notch's DCPU-16

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