1227747 ROM image?

[jim_in_dorris]

I am not sure if I have seen the binary of the second half of the $42 binary anywhere. If someone has a dead 7747, we could unsolder the second rom and read it.

[shimniok]

Thanks guys. I didn't want to pollute the other thread with this question. :) Supposedly one can pull the image without desoldering using some pins exposed somewhere. Unfortunately the website that used to spell it out is lost to time. There's another site that has binaries that you can load into the EPROM and it'll spit out the data via serial.

[RobertISaar]

There's another site that has binaries that you can load into the EPROM and it'll spit out the data via serial.

i seem to remember reading about this on either the DIY-EFI site in the GM_ECM section or possibly directly from Ludis, i forget which at this point. in any case, that's the easiest route to go, though i seem to remember that the pins used for the serial communications were the IAC drivers, instead of the normal ALDL circuit?

[shimniok]

Here's the site I found: http://www.exatorq.com/ludis_obd1/spit.html

It has various EPROM images for dumping the ROM. You're right; it doesn't use the standard ALDL pin.

Ground ECM pins A12 & D1. Connect a 12 volt power source to ECM pins A6, B1 & C16. Connect the positive end of a 1 µF capacitor to ECM pin C6. Note, this is not the regular ALDL output pin. Connect the negative end of the capacitor to your computer's RxD serial port input. (Also provide a ground connection between the ECM and serial port.) On the computer, run a terminal emulator set to 8-N-2 and 9600 baud. The ROM contents should now be dumped repeatedly to your terminal in Motorola S19 format.