PC's, EFI, and Online tuning

[Wayne Blair]

Two pennies worth,

Online tuning:

If you go the route of using battery backed ram (in Delco's any way) after
you make some wiring modes to ecu and do some coding you should be able to
write your new data into the sram (what was the rom) with the diagnostic
link while the engine is running. This may need a patch to the comms
routine of the ECU code but I beleive that it is easy after you really
understanding the diagnostic protocol. Diagnostic tools can already write
to other addresses of the ECU's memory map - to perform test function cant
they ??.

OR you could use DUAL port RAM chips build a board that maps the data area
of your specific application to the dual port ram and still uses the rom
for code (a few pals or gals or descrete logic needed). Now with a serial
port connected to one side of the dual port and the ecu connected to the
other you change what you like whenever and the ECU just does it thing.

Both systems are hic up less. You dont have to worry about paging in out
between chips between cycles, and them slow eprom emulators can stay on the
shelf - who want to download the whole file every time you change a byte. 



PC EFI and building complete systems

There was at least a prototype of an Engine Management front end chip
produced buy a big Semiconductor company. This allowed any CPU of choice to
be the brains of an ECU the chip did all the hard work - figure out where
the crank was, rpm, load it had A/D and it goes on. All the CPU had to do
was pass a few parametrs to the chip every few milliseconds and it did the
rest. I can find the data sheet tonite if any one is interested. 

Unfortunately I think it was such a great device very concerned interests
ensured it was squashed or maybe it has a new name. Does any one else know
about a similar chip. When I apporached the supplier down under ( a few
years ago) they reported their supprise when the could not supply as they
had strong interest from the field.

ttfn

wayne