Dumping ROM combo chips

[Bruce Plecan]

-----Original Message-----
From: Don.F.Broadus at ucm.com <Don.F.Broadus at ucm.com>
To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
Date: Monday, November 30, 1998 1:21 PM
Subject: RE: Dumping ROM combo chips


>Thanks guys for looking it up. The ECM was out of a full sized Chevy taxi.
>U-Pull-it had marked 90  5.7 TBI on the outside
>Of the car but I wasn't sure if it was since the body style looked older
and
>the tail lights were guide 1987, I couldn't find the vin number any where.
>Is this ECM 747 compatible ?

Does it plug in?, yes, will it work, correctly?, Only if you add an air
intake temp sensor (I think all the car TBI's used air temp).  Different
table locations, I venture to say.

Bruce
>
>Thanks for putting up with all of my questions
>
>Don
>
> -----Original Message-----
> From: Bruce Plecan [SMTP:nacelp at bright.net]
> Sent: Monday, November 30, 1998 9:08 AM
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: Re: Dumping ROM combo chips
>
>
> -----Original Message-----
> From: Don.F.Broadus at ucm.com <Don.F.Broadus at ucm.com>
> To: diy_efi at efi332.eng.ohio-state.edu
><diy_efi at efi332.eng.ohio-state.edu>
> Date: Monday, November 30, 1998 9:44 AM
> Subject: RE: Dumping ROM combo chips
>
> 1990 5.7L eng code 7,   helps to have a rough year of application if
> possible.
> Bruce
>
>
> >Thanks very much for the info ! I have found another ECM this week,
>could
> >you please identify this one also
> >1228746 AUML 1209  the engine was out of the car so I don't know
>the
> >application.
> >
> >Thanks Don
> >
> > -----Original Message-----
> > From: Bruce Plecan [SMTP:nacelp at bright.net]
> > Sent: Wednesday, November 25, 1998 6:21 PM
> > To: diy_efi at efi332.eng.ohio-state.edu
> > Subject: Re: Dumping ROM combo chips
> >
> >
> > -----Original Message-----
> > From: Don.F.Broadus at ucm.com <Don.F.Broadus at ucm.com>
> > To: diy_efi at efi332.eng.ohio-state.edu
> ><diy_efi at efi332.eng.ohio-state.edu>
> > Date: Wednesday, November 25, 1998 10:00 AM
> > Subject: RE: Dumping ROM combo chips
> >
> >
> > >Could I bother you for info on  Prom ABHC 7377 out of a 1227747
>ECM
> >from a
> > >1987
> > >Full sized GMC Van.  Would this PROM work on a  stock 5.7L
>engine
> >
> > Yes, it's out of a G Van.  If the 5.7 is in something much
>lighter,
> > different then the match will be less than perfect drivibility
>wise.
> > GM looks at lots of things when they do a calibration, the finer
> > it is tuned the less transferable it is.
> > Bruce
> > >
> > >Thanks Don
> > >
> > > -----Original Message-----
> > > From: Ludis Langens [SMTP:ludis at cruzers.com]
> > > Sent: Wednesday, November 18, 1998 2:55 PM
> > > To: Diy_efi
> > > Subject: Dumping ROM combo chips
> > >
> > > Many of the older GM ECMs use a 40 pin DIP combination
>ROM/RAM/IO
> > >chip.
> > > (The pinout is on my web site.)  This chip has 4K bytes of ROM,
> >128
> > > bytes of RAM, and 8 digital I/O lines.  The chip receives all 16
> > > processor address lines and does it's own address decoding.
> > >
> > > If you wish to read out the ROM from one of these out of
>circuit,
> > >you'll
> > > need to provide an E clock signal.  I wired up an adapter to
>read
> > >these
> > > chips in a PROM reader as a 27512.  The RAM and I/O appear to
>read
> > >OK
> > > with E tied high.  The ROM however doesn't.  The PROM ~OE signal
> > >needed
> > > to be inverted and applied to the combo chip's E input.
> > >
> > > --
> > > Ludis Langens                               ludis (at) cruzers
> >(dot)
> > >com
> > > Mac, Fiero, & engine controller goodies:
> > >http://www.cruzers.com/~ludis/
> > >
> >
>