EPROMs in non GM ECMs

[Christian Hack]

On Tue, 10 Feb 1998, Ludis Langens wrote:

> What sizes/types of EPROMs are used by other companies?  I know that I
> might as well skip all Fords because they use nonstandard stuff.  But
> what about Chrysler and the Japanese and European engine controllers?
> 

I have a Nissan RB30ET engine in my Australian Commodore (3.0 litre inline
6 with turbo). The engine computer which contains a majority of Hitachi
chips is apparently based around the Bosch Motronic system. It has a Bosch
part number as well as a GMH part number. The system is based around a
Hitachi HD6802 processor

Anyways, it contains a 16kx8 masked ROM, which I have currently replaced
with a 27C128 EPROM. This is only for the engine computer. The trans has
its own computer on the other side of the car.

All the models after the VL (mine) use GM engine computers with ROMs of
varying size from 16k upto 64k (I think). The latter ones apparently
control the trans as well.

BTW: Anyone with any ideas on how to modify it would be appreciated. I
have a dissassembled listing of the ROM (about 13 pages of 6 columns each
and ~80 lines per column!). I believe it is the same as one of the engine
computers on the Jim Wolf technology page. He modifies computers for the
Nissan 300ZX VG30 (V6) engine so I think that it would be the same
computer with a fairly different ROM.

I am a software engineer (just graduated!) so I have no problem
interpreting the code but because I have no information on the support
circuitry it is very difficult to understand since the program refers to
addresses not in the ROM (i.e. I/O ports on external circuitry). I have
looked everywhere. I have left the list of chip numbers at home so if
anyone thinks they can help email me and I will post the list. 

Thanks

Christian Hack
e9329002 at student.uq.edu.au