[Diy_efi] Nippondenso / Toyota TCCS

[Torbjörn Forsman]

The Nippondenso ECUs used by Toyota in the late eighties use to have a 
mask rom microcontroller that only bears a ND part number. Does anyone 
have a clue what kind of microcontroller it really is?

Some observations:
42-pin DIL package.
Date code with one digit for the year, one letter for the month and then 
four random digits. I.e. 6K4711 for a unit which is made in late 1986.
VCC on pins 20, 41 and 42, GND on pin 21. Reset pin 3, active low. Clock 
crystal (12,0 MHz) between pins 15 and 16.

Best regards

Torbj?rn Forsman