P J Moran

I know the parameters are on the prom, but where does the actual program (code) live?

There has been some discussion of using an '89 .bin (6E) in place of an '87 .bin (32B). I compared the parameter lists and found that there are more "tunable" parameters on the 6E than on the 32B. So how can the 6E data work with a computer from which a 32B prom was removed? If the program is in the computer and the tables are on the prom, how can you change parameters that weren't on the original prom and have any affect?

Now, if the program itself also lives on the prom, I can see how this might work, but it still looks iffy to me.

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'87 IROC 5.7l TPI - original owner!

Grim Reaper

The actual code is actually on the eprom too. About the first third of the eproms memory is tables and the remaining 2/3's are the actual machine code.

Technically, it is completely possible to re-do the machine code (or part of it) if you are knowledgable of the Motorolla's machine code/assembly language itself in that eprom.

I am currently looking for a good book on the Motorolla's assembly language and debating about re-writing some of the code myself to make it function the way I want, instead of the way GM designed it.

Brent

iTrader: (1)

In addition, some C3 ecms have some of the code stored on a hardwired ROM and the rest on the EPROM.

Grim Reaper

Thanks for the additional info Brent. Its amazing about the differences sometimes. Don't worry though PJ, you have a "P4" which has all the info on the eprom.

[This message has been edited by Glenn91L98GTA (edited January 12, 2001).]

Guest

Glenn, try a university library somewhere. Where I went to school they had a book that dealt only with the Motorola dinosaur computers, it was printed in 86 IIRC, and the ECM used in our cars was in there. I didnt even want to think about rewriting the program though, so I never bothered to learn it

Grim Reaper

Thanks for the tip Madmax. I might even try one of the public libraries (they are always good for out-of-date books). I do have a really old microprocessor book from my college days, but that book came out when the Z80 CPU was leading art.

Back in my "old days" when I use to be a "bit twiddler" I did a lot of assembly language programming, but that was for the IBM 370s. I even wrote code that was "self-modifying". So I know a lot of the concepts of assembly language programming...just have to bone up on the instruction set itself.

But as I read the 8D hack, I keep thinking...wouldn't be great to alter the code itself to do what I want it to do, or what I think it should do.

[This message has been edited by Glenn91L98GTA (edited January 12, 2001).]

P J Moran

Thanks Glen. I guess I'm about ready to register TunerCat and get the 6E TDF and try to run it. Since you get two, I'll also get the 32B, just in case

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'87 IROC 5.7l TPI - original owner!

Grim Reaper

Actually you only get 1 free choice. It comes included with 42.