couple questions

[96TurboTA]

Are the 96-97 OBDII pcms part of the P4 family? Do the external flash memory chips contain the code as well as data? How do I know where to start the disassembly since the reset vector is on the motorola CPU?

[96TurboTA]

Ok, I realize my posts have been really vague, so I'll attempt to clear up things. I've got LT1_edit for my 96 TransAm. It's got a 383 and a single turbo. What I want to do is read the PCM, and not only get the data tables, but also the operating system code. My hope is to be able to modify the gm code for a 2bar map sensor. I know this won't be a trivial task, but I'd like to try. I'm familiar with the Motorola HC11 code, as I used it extensively in college. I am an EE, not that I know anything, but I'm not totally clueless either. My first problem is how to get the code out of the PCM. My first instinct tells me that GM would put the OS code locked in the motorola chip/s. However, after thinking about it, they may need to update the OS down the line if a problem is found, and hence put it in the flash chips. So my questions are: Where is the OS stored?, and if it's not on the motorola chip, how can I find the start of the code. I've never programmed with external eeprom, only the onboard memory(internal to the motorola HC11). With the onboard memory, the reset vector was always at FFFE, and FFFF. Any help or guidance would be great. Thanks in advance.
Josh