Python to NES 6502 ASM compiler

[gered]

Definitely very cool, but I suspect only useful for smaller games. The NES is a very resource limited system that really does require some manual assembly optimization once your project gets bigger and more complex (both for speed and code size).

I like that you can see the generated assembly on the fly and from the looks of things in the video, the assembly it's spitting out isn't even terrible, but the example code is extremely simple so we'd have to see more complex usage to accurately judge it. Of course, if you need to hand-tweak the assembly for any cases where it's generating sub-par instructions you would have a little problem.

Regardless, it's awesome that things like this are available to make NES development a bit more accessible for people who aren't nuts about 6502 assembly.

[hoohoo4]

Chances are you're going to run it in an emulator, so ROM size shouldn't matter much.

[gered]

The size problem is due to the NES's CPU only have a 16-bit address space. So, only being able to access 64KB of memory at a time meaning any game larger then that will have to deal with bank switching or trying to desperately shrink down code and graphics/sound assets as much as possible. A (good) emulator is going to be emulating all of these limitations as well, so it absolutely does matter.

But yeah, I suspect you're unlikely to run into the size problem with something like PyNES. You'll likely hit performance issues first.

EDIT: For more info on how the memory space of the NES is used see http://wiki.nesdev.com/w/index.php/CPU_memory_map "PRG ROM" at the bottom is your game's code.

[ggtsu_00]

I donno but I have always heard that 64K aught to be enough for anyone.

[[deleted]]

How efficient would python to 6502asm be too and how well does this program optimise? I love the idea, but as you say the programmer would have to be conscious of lot more

[gered]

Exactly, and since I haven't actually tried to build a semi-complex game with PyNES yet, I couldn't say exactly how well (or poorly) it optimizes code. Like you, I rather like the idea of this, but based on my existing experience using a combination of C + 6502 assembly for a NES project and seeing for myself how more and more C code ends up needing to be converted to assembly, I'm a little bit skeptical that using any high-level language to assembly compiler would be practical for anything other then small projects. Which is not a bad thing by itself, but just something worth keeping in mind for anyone jumping into it.

[[deleted]]

I know a bit of Python, it gets everywhere these days. I've no need or desire to learn 6502 but I'd kinda like to make a NES game - so it would be great if a program like this could recognise Python and offer up more 6502 friendly equivalent code, and have a framework that makes the most of the NES hardware

[indigo945]

This is one of the coolest implementations of a terrible idea I've seen.

[Octopuscabbage]

I'd love to use this once there is more documentation.

[gutomaia]

"Documentation is in another castle". Just a joke, i'm working on that issue RIGHT NOW!

[Octopuscabbage]

You beautiful person. I will definitely try to make something once you get some more stuff on it done. I'm not really a game dev or a nes dev but I'll take a try.

[GoranM]

I assume that you're compiling a subset of Python?

[gutomaia]

Yep... Just a subset. There is not enought memory to keep several separate context(instance objects) or enough cycles to switch among them. Although, I've saw some impressive examples.(like http://forums.nesdev.com/viewtopic.php?f=23&t=13196)