Disassembly

[DAVE_HEMPSTEAD at HP-Andover-om3.om.hp.com]

Hi everyone,
    I learned a couple of things this weekend about my 95 ECM.  First thanks to 
whoever posted the document of the P4 system.  Very interesting reading.

    My 95 also supports command modes 2 (read out a block of 64 bytes of 
memory), command mode 3 (read out up to 8 individual addresses in memory) and 
command mode C.

    I found that command mode C lets you program your VIN and END MODEL number 
(what ever that is).  The format for command C is:
      0xF4, length, 0x0C, 0x01, 17 byte VIN, cksum
or    0xF4, length, 0x0C, 0x02, 4 byte End Model, cksum


    Note that for '95, the messages start with an 0xF4.

    I did check command mode 4 and 5.  They do write to ram locations, and 
according to the document, sets engine parms to your sent values.

    I believe that 94's and 95's are the same.  
    I have not been able to find the Motorola App Note AN1010 (I did find 1060).
 Can anyone point me to it?

    Can someone explain to me what technology is used to store the VIN in the 
ECM?  Is it EEPROM???

Thanks,
Dave Hempstead