Looking for Vic20 Kernel ROM disassembly

RJBowman · Post by **RJBowman** » Sat Dec 03, 2011 2:16 pm

I am looking for a Vic20 Kernel ROM disassembly. I have found articles by a guy named Richard Cini with parts of the disassembly, with a stated goal of documenting the entire ROM, but I have not found the complete disassembly all together. Does Richard Cini have this all archived on a web site somewhere?

Kweepa · Post by **Kweepa** » Sat Dec 03, 2011 4:45 pm

Yeah, Cini's C= hacking articles at http://ffd2.com/fridge/chacking/ are the only disassembly I'm aware of.
I think it would make a useful group project for the forums.

Wilson · Post by **Wilson** » Sat Dec 03, 2011 5:07 pm

Kweepa wrote:I think it would make a useful group project for the forums.

If may be able to make that a very short project.

I made an almost completely documented disassembly based off of Harlekin/Fairlight's C64 JiffyDOS disassembly last summer while working on a Vic-20 JiffyDOS port (still plan on finishing that when I have time btw), but I am not sure what the legality of distributing it is. I'd love to share and maybe even get someone to help finish JiffyDOS, but I'm very wary of any code sharing. The laws surrounding the reverse engineering of code seem to be very cloudy.

If you simply want an undocumented disassembly, you can of course disassemble it yourself.

Kweepa · Post by **Kweepa** » Sat Dec 03, 2011 7:43 pm

I don't care about JiffyDOS.
You say you have an almost complete kernal disassembly? Let's see that then!

Wilson · Post by **Wilson** » Tue Dec 06, 2011 6:35 pm

Kweepa wrote: I don't care about JiffyDOS

Sorry, I didn't intend for that to be the focus of my post, but looking back I see it is. I suppose I don't see an issue with sharing the documented unmodified kernal. Give me 2-3 weeks. I'm at school (away from my computer) until the end of next week.

Kweepa · Post by **Kweepa** » Tue Dec 06, 2011 7:17 pm

Cool, thanks!

Wilson · Post by **Wilson** » Sun Jan 08, 2012 10:36 am

I've been reluctant to release this disassembly because it's pretty rough. There are a lot of TODO's in here that could use a look at. Also, I forgot how large a chunk of the kernal is dedicated to tape access. Since that was not relevant to JiffyDOS, it remains uncommented for now. As I said before, I took 99% of the comments from Harlekin's C64 JiffyDOS disassembly. There might be an occasional reference to a CIA or something as such...Anyway, I've made it sound pretty horrible

, but it's fairly useful overall I think.

Download

Leeeeee · Post by **Leeeeee** » Wed Jan 11, 2012 12:51 am

I've put a new page up.

Enjoy.

Lee.

Wilson · Post by **Wilson** » Wed Jan 11, 2012 7:01 pm

I really wished you'd said you were working on that...

Fantastic job though. It looks extremely complete.

Kweepa · Post by **Kweepa** » Wed Jan 11, 2012 9:50 pm

Yes, thanks for this! Invaluable!

Leeeeee · Post by **Leeeeee** » Wed Jan 11, 2012 10:05 pm

I really wished you'd said you were working on that...

If I'd said you wouldn't have started yours and I wouldn't have been encouraged to say about mine. The only way that would have worked was if you had a time machine.

Fantastic job though. It looks extremely complete.

It's not, there's lots of things still to resolve. For instance, when I disassembled to a branch I'd fill in the branch condition and continue from the next instruction leaving what the branch achieves as something to do later. Most of them are still like that.

Today I've mostly filled in literal string bytes and added keyword token values as constants.

Version is now 1.01

Lee.

matsondawson · Post by **matsondawson** » Mon Jan 16, 2012 6:59 pm

Could I put a copy up on my site in the reference section of http://www.mdawson.net/vic20chrome/vic20.php ?
Or could you host a copy that's not in a ZIP that I could put a reference to?