I had this running as a test on my MR2 with the Honda ECU back in 2009 or so:
It just takes the IGT signal and splits it out to 4 (or however many you want, up to 10) separate ignition channels, while using the edge of that signal to increment the coil counter. You have to tap the input of IC10 (I think, I forget which pin it was) to get the logic-level CYP signal for sync. It uses an edge detector to pick up the CYP signal, which resets the counter and it's sync'd from then on.
The BIP373s were for driving dumb ignition coils. The logic output of the 4081 will drive any coil with a built-in igniter. I used QR25 coils, but it worked with k-series coils on the bench as well.
Only problem is that it won't work with ignition cut rev limits. I have another version that I half-ass worked on that would use either IGT or TDC to increment the counter, but I never tried it out. It took forever to start too. Would probably fire up faster if you batch fire the coils during cranking. Not a difficult addition to make.
If someone wanted to pick it up and finish development, feel free.
Wanna hear some insane shit? The 4AGE kids built their own COP setups and just batch fired the coils full-time. *shudder*