Dumping a Mistubishi ECU

[Ronald T. Webb]

I have what seems to be the same unit (from a geo tracker). I've thoufht
about the same thing, and done what looks like the same research (I found
the disassembler anyway).

I found no specs on the ROM.

The MELPS 7700 family seems to be a microcontroller version of the 6502.
Assemblers, a C compiler, and even a complete integrated development system
are available.

One normal method of getting a dump is to substitute a chunk of code I've
seen called a "code spitter" program, then monitor address and data lines
with a logic analyzer. To do this, you have to remove the ROM from the
board (my PLCC is soldered in). I do not know enough about the peripherals
used, or the memory map, and the board has what appear to be proprietary
composite devices all over it.

The bottom line is "I gave up". It'd be easier to rebuild the system around
a '7747...


"Barry E. King" wrote:

> Does anyone have an inexpensive means of dumping the contents of an
> Mitsubishi M37793 84 pin PLCC?  It appears this processor from the 7700
> family is a 16 bit enhanced version of the 6502 of all things.  I can
> disassemble it once dumped.
>
> Thanks,
>
> Barry