PC Based EFI

[ALIPPER at aol.com]

Jim, I'm glad to see your interest in the PC-based EFI.  You ask:

>	First. I looked at the way you decode the address 
>structure on the ISA bus, and how does that stop other 
>devices from addressing the injector. Since you only use 
>the first 5 address lines....

The addressing is making use of the CPU's I/O port addressing mode, NOT
memory addressing.  Port addressing only uses A0-A9.  My design decodes A5-A9
as the
address block in which the EFI will operate, then within that, it only uses
A0-A4 for the locations it requires.  (note the inclusion of the IOR and IOW
signals in order to enable any of the devices).

>	Second. The circuit you use to drive the injector. Your 
>not drive the injector all by yourself are you? It looks 
>to me as though you're giving it to the cars ignition 
>system.. Could you clarify this.

The injector may be operated in several modes (see the doc files).
 Ordinarily, it fires the injector(s) once every spark (as do virtually all
TBI systems).  In certain cicumstances (e.g. starting and rapid
accelleration) this is not adequate.  During these times, it may be switched
to async mode where the injector fires off of on of the timer outputs at an
adjustable interval.  There is no need at all for interrupts in this design,
thereby simplifying the implementation.  As you can see, it can even be
operated from BASIC.  Hope this helps.

                                                  - Al -