Mac-01 vs. Mac-02

[ptimmerm@mashtun.JPL.NASA.GOV]

John, you can determine whether you have a mac-01 or mac-02 
simply by the size of the unit.  The earlier (unlikely) 
unit is about half the size of the later.  If it seems
normal sized, similar to a car stero, it's a mac-02.
My car with very similar build date (and later brought up
to us spec) has the larger mac-02.  

As for modifying the chip versus modifying the output of the 
pressure transducer, what  more do you hope to accomplish, 
other than advancing the timing (which the "hack" does nicely).  
I can modify you box to give any amount of ignition advance  and 
ECU cutoff you  want without the hassle of modifying the chip, 
or doing anything irreversible or vaguely smelling of rosin core 
solder.  A true chip hack for a mac-02 is, in my opinion, not
desirable, unless you are trying to do something totally 
unstreetable.  Let me know if I can be of more help.

paul timmerman