ECM 1227748, creating a new ECU file?

[TK]

I've done some work on the 748 code for the 4 banger Fiero/Grand Am. Why, I
don't know ........

I can upload it to incoming if anyone cares.

TK


----- Original Message -----
From: steve ravet <sravet at arm.com>
To: <gmecm at diy-efi.org>
Sent: Tuesday, February 20, 2001 12:05 PM
Subject: Re: ECM 1227748, creating a new ECU file?


> Nick, I have the same ECM and am hoping to put it on a boat some day.  I
> have looked through a few bin files and there are 7 or 8 or so 3d tables
> that jump right out at you.  That's the extent of my work, though, I
> don't know what the tables do.  Tunercat doesn't seem to support 1227748
> although he might be talked into it.  I doubt Terry K has an editor
> either, just because it's not that common an ECM.  but who knows, as
> him.  I'd be interested in swapping info on this ECM if you come up with
> anything.
>
> Nick McAlpin wrote:
> >
> > What does it take to make a new ECU file from scratch?
> >
> > I'm the one with an 88 coupe who got some help from the list over
> > the past few days (thanks all!) and i am interested in working with
> > the EPROM code/tables a little bit but being a less common ECM,
> > the ECU doesn't seem to exist.
> >
> > So, my question, is building an ECU really not much more than
> > looking through the bits of the .BIN, identifying tables purely by
> > pattern and then playing with them to find out what they do?  what
> > about single byte memory spots - do you guys just change the
> > value one byte at a time to find out what it does?
>
> Basically.  Once you find the tables, you can start changing values
> (like zero out an entire line) and see what the effect is on timing or
> fuel.  You don't want to do that on a car, you want to do it on an ECM
> testbench.  There is some information about building an ECM testbench on
> the WWW page http://diy-efi.org/gmecm/projects/ecm_testbench/
>
> There is some info in the archives, mostly from Ludis, about this ECM.
> Search around in there also.
>
> >
> > is there any standardization in the table formats of ECM's?  For ex.
> > if I find a table of size X columns and Y rows that it is probably
> > table Z?  or is every ECM/bin different.
>
> As I understand it, bins that share the same mask code have tables in
> the same places, and the same sizes, as each other.
>
> >
> > It seems like if I have to start from total scratch, I could end up
> > burning 1000's of EPROMS and doing a lot of guesswork (and hope
> > not to break anything in the meantime?)
>
> Yes to the 1000's (unless you get an emulator), no to the breaking stuff
> if you use an ecm testbench.
>
> --steve
>
> --
> Steve Ravet
> steve.ravet at arm.com
> ARM,Inc.
> www.arm.com
> --------------------------------------------------------------------------
--
> To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>
>

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org