Where to start?

[Frederic Breitwieser]

> 555s for VSS, and rpm.  VSS is usually 2,000 ppm, or 4,000 ppm
>     DPDT switch for VSS on, P/N is grounded as vss signal applied.
>     DPDT switch for ignition pulses so MAP signal changes when
>                 the engine starts.  (figure 6,800 rpm redline for v-8)
>     On/Off for memory clear.
>     On/Off for ecm, injectors, 555s, and misc on.

I use a parallel port cable, connected to flip-flops also,
thus achieving the 50/50 duty cycle as well, as follows:

DO - vss in
D1 - MAF in
PTR Ready - ground.

I defined a "generic ascii printer" in Windows, and just
dump core files to the printer port.  Was easy, though
creating the "print jobs" had to be done with an editor, and
took a lot of cutting and pasting.  Notepad is not the right
way to do this apparently.

I had intended to actually write real code where I could
adjust "dials" on the PC, and have it provide a full cycle
use test of the ECM, however I didn't get that industrious
unfortunately.

-- 
Frederic Breitwieser
Bridgeport, CT 06606

http://www.xephic.dynip.com
1993 Superchaged Lincoln Continental
1989 500cid Turbocharged HWMMV
1975 Dodge D200 Club Cab (soon to be twin turbo 440)
2000 Buick GTP (twin turbo V6)