A 6502 disassembler that runs on the NES.

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slembcke
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A 6502 disassembler that runs on the NES.

Post by slembcke » Sat Nov 25, 2017 10:49 pm

This might be the most useless piece of software I've ever written. Haha.

In case you ever wanted a 6502 disassembler to run on the NES that can only disassemble it's own source code:
Image

Donload source/.nes: http://files.slembcke.net/temp/Disassembler.tgz

edit: added a download link
Last edited by slembcke on Mon Nov 27, 2017 3:53 pm, edited 1 time in total.

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Kasumi
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Re: A 6502 disassembler that runs on the NES.

Post by Kasumi » Sat Nov 25, 2017 11:16 pm

That's actually really cool. Is the code small enough to fit in WRAM? Because it might be cool to hack into other games.

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tokumaru
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Re: A 6502 disassembler that runs on the NES.

Post by tokumaru » Sun Nov 26, 2017 12:45 am

That could be fun to play with, even if not particularly useful.

Totally unrelated, but I couldn't help noticing that the animated GIF was made from lossily compressed images, resulting in a huge file due to the numerous color artifacts around the text. If you used clean images instead, that GIF could easily be 10 times smaller, and it'd look better too. When possible, avoid JPEG/MPEG when capturing screenshots/video from old consoles.


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pubby
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Re: A 6502 disassembler that runs on the NES.

Post by pubby » Mon Nov 27, 2017 4:42 am

There's no link?

How does it determine the alignment of the code?

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slembcke
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Re: A 6502 disassembler that runs on the NES.

Post by slembcke » Mon Nov 27, 2017 3:57 pm

I'm kind of surprised that people want to see the code for this. :p I added a download link to the first post.

This is my first cc65 program in 10+ years (I think I last used it in like 2003), and first NES project so I wouldn't expect to learn much from it. Compared to the 2 kb Apple II monitor program, this 4+ kb disassembler is a monstrosity. :p It was easy to make though.

@puby It doesn't. It's starts at $c000, and there is only one code segment.

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rainwarrior
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Re: A 6502 disassembler that runs on the NES.

Post by rainwarrior » Tue Nov 28, 2017 11:30 pm

I let it go all the way around just to see.

Didn't quite manage to wrap perfectly. ;)
disassembler_wrap.png
disassembler_wrap.png (3.26 KiB) Viewed 4448 times

adam_smasher
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Re: A 6502 disassembler that runs on the NES.

Post by adam_smasher » Thu Nov 30, 2017 11:52 am

Image

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Punch
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Re: A 6502 disassembler that runs on the NES.

Post by Punch » Fri Dec 01, 2017 10:23 am

Is that a "quine"?
This is a block of text that can be added to posts you make. There is a 255 character limit.

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slembcke
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Re: A 6502 disassembler that runs on the NES.

Post by slembcke » Fri Dec 15, 2017 1:36 am

Now with split scrolling!
Image

Fixed the jerky scrolling by switching to NMIs as well. I had forgotten how much fun 6502 assembly was even if it's not very practical in 2018. :p

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