Quote Originally Posted by NomakeWan View Post
The stock chip was a 27C256, not a 27C512. Usually when you burn a smaller BIN to a larger chip, you use a technique called "BIN stacking" to duplicate the data (in the case of a 27C512, this would mean burning two copies of the BIN to the chip, stacked on top of one another). This way the entire program space is filled, and you know that the entry vector will be correct.

If you have an ECM that supports 8192 baud ALDL, you could also pull the data by using a Mode 3 request. The program Flashhack by steveo includes the ability to dump ROMs over ALDL from any computer. I used it to dump CCMs from all three of my Corvettes without removing the computers from the car, for example: https://ecmhack.com/flashhack/

But since you have physical access to the chip, using the BURN2 (or any chip burner on the planet) to read it is the correct course of action. Just make sure you actually have the correct chip selected and are reading the correct program data addresses.
How do you do a mode 3 request, i think i might probably go that route. I could also possibly retrieve my old bin files from my old laptops hard drive but i think mode 3 or a way to read the 27SF512 flash chip would be a bit easier and simpler. Thanks