3800 series II swap, please read :)

[Ludis Langens]

TK wrote:
> 
> From that I can tell, the speedo VSS output is just buffered VSS signal. I
> can move the divisor and road speed constant all over hell and the ECM
> changes but not the VSS output to the speedo.

If this ECM is at all like the '730 ECM, there is a seperate divisor
just for the speedo/cruise outputs of the ECM.  The dividing happens in
the chip (64992) which contains the VSS zero crossing detector and the
ECM->speedo VSS output driver.  This dividing is totally independent of
anything else in the ECM.  There are seven possible divisors: 1, 6, 7,
8, 9, 10, and 11.  In the '730, a 3 bit selector code is written to an
output port in the 45154 chip.

-- 
Ludis Langens                               ludis (at) cruzers (dot) com
Mac, Fiero, & engine controller goodies:  http://www.cruzers.com/~ludis/