Re: Franco Sprocket - eprom burners?

[Orin Eman <orin@WOLFENET.com>]

> On Fri, 21 Nov 1997, Huw Powell wrote:

> > >  Another way to compensate is to burn a special ignition PROM chip. If you have
> > > a computer hacker friend who will do you a favor, the chip only costs about
> > > $10. If you take it to an auto company, the chip runs about
> > > $300.
> > 
> > OK guys n gals, it seems like there is a cost effective way to use this cam gear
> > in the na cars.  I know a few of you out there have eprom burners, what is the
> > possibility of finding out the "special ignition" details and making a few?
> > 
> Huw,

> 	I talked to George about this very thing, and Orin Eman was 
> checking into the code to see how often the ECU needs that distributor 
> reference.   Orin thought it was only needed when the ECU detected 
> knock.   If Orin can figure out away to reprogram the ECU so that it 
> doesn't need this signal, then we could simply bolt the Franco gear on 
> the cam, and enjoy it.

For the MAC11B:

E7E7:	7E FF E1	JMP	FFE1

FFE1:	5C		INCB
FFE2:	26 01		BNE	FFE5
FFE4:	5C		INCB
FFE5:	7E E7 EB	JMP	E7EB
FFE8:

Adjust the checksum byte at E6FD to make the checksum 0 mod 256.

This should keep the cylinder counter correct.  (255 which is
0 mod 5 becomes 1, anything else is merely incremented.)

You should check and understand the above before using it!  I haven't
tested it yet!!!  (AND it was assembled by hand.)

Orin.