PC's and EFI

[Frederic Breitwieser]

>controlls the would send a string of 1s and 0s to another routine that
>would send 00000000 to the parellel port when it receives a 0, and
>00000001 or 00000010 or whatever (depending on which injecter is being
>fired) to the parellel port.

Well, since the cylinders ALWAYS fire in the same order, your method,
whether PC or PIC or other system, would be absolutely suitable.

In fact, you could write a 10000000 to the injector port, then shift right,
then write the 01000000 back. Continue this until the carry flag is set,
then you have one or two additional instructions to shove a 10000000 into
the port when the carry flag is set.  Or undercarry flag I mean.  You get
the idea.

Good idea!

The from scratch thing I started working on way back using a 68HC11E9 had
memory mapped I/O for all of the input/outputs, making device reading
simply a "poke" or "peek" type of thing like basic.

The other idea I had, was to cascade two 74HC193's to give an 8-bit value
clocked off the tach output, thus the microprocessor wouldn't have to count
each and every pulse - just subtracted the current value from the last one,
and the system would know how far things rotated.  Eventually, I was going
to take it a step further and have the crank wheel I was going to make
reset the '193's so I'd have 360 markers on the crank wheel, and the system
would count from 0-359.

never really finished it however.


Frederic Breitwieser
Bridgeport, CT 06606

Homebrew Automotive Website:
http://www.xephic.dynip.com/

1993 Supercharged Lincoln Continental
1989 HMMWV
2000 Buick-Powered Mid-Engined Sports Car