Another Intro + DIS w/ '749 .bin

[Tedscj at aol.com]

Hi,
  My profession relates neither to automobiles nor electronics.  Cars have
been my hobby since I was old enough to drive and bought my first car (a $200
'62 Buick Skylark).  I don't even qualify in calling myself hobbyist when it
comes to electronics (analog or digital).  My only experience in programming
was Basic on an Apple II in highschool!  My first computer was a Pentium with
W95.  So as you can see, I don't know much, but I'm smart enough to figure
most things out.
My project is half way done already (the easy half!)  I have adapted a '730
with DIS to my Jag 4.2L straight 6.  It works pretty well as is, but of course
I would like to make it work better!
  I want to figure out how to get the sy/ty .bin to work in my '730 with the
DIS.  At this stage, I don't even have an EPROM programmer/reader yet.  So for
now I'm just reading and theorizing.  I know Bruce is already figuring out how
to get the sy/ty bin running in the '730, and I know others would like to be
able to use DIS too.
Here's what I know (or think I know) so far:
1: I read in a Chilton manual in the library that the signal the DIS module
sends out is inverse to the signal an HEI module sends.
2: I read in the archives that someone tried to run a .bin from a 6cyl DIS on
an engine with a distributor and it "just wouldn't run right"  They didn't say
it wouldn't run!  Just not "right."  However, I have never heard anyone say
that an HEI based .bin (like the sy/ty .bin) wouldn't run on a car with DIS.
3: after reading the P4 document, I just learned that the P4 computer controls
dwell time.  I had always thought that was handled by the module.  I think
this may be the source of the problem, Not the inverse signal.  The document
also states that the P4 reads the falling edge of the signal to determine RPM.
Even an inverse signal would still have the same number of falling edges at
the same frequency, so I doubt that's the problem.  Though it may cause things
to be a few degrees off, but that could be fixed through the base reference
angle.
Could it be that the dwell computation for a DIS .bin would be to aggressive
to work well with a dizzy, whereas a dizzy based .bin (sy/ty) would work with
a DIS module albeit with rather conservative dwell times that don't take full
advantage of DIS?
I guess there is only one way to find out, and that is to try it!  Which means
I need to find a programmer that will work with a pentium based system (it
seems that most won't) without causing me to go broke!  Any suggestions?

Ted