3800 series II swap, please read :)

[TK]

Hi Ludis,

That is exactly what the ECM has. However, when I change those bytes, the 4k
and 2k outputs don't seem to change only the ECM view of NMPH. I think it
affects the IPC stream too for the dashboard. Guess I could try it again. I
tried it a few times after the swap was first completed.

Anything cosmic in the divisors? (Why those values).

Terry
-----Original Message-----
From: Ludis Langens <ludis at cruzers.com>
To: gmecm at efi332.eng.ohio-state.edu <gmecm at efi332.eng.ohio-state.edu>
Date: Sunday, July 11, 1999 3:34 PM
Subject: Re: 3800 series II swap, please read :)


>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/
>