Dumping ROM combo chips

[Don.F.Broadus at ucm.com]

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 ?
 
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/
	> >
	>