Need some IC Help

write to NEC

The uPA2004C is probably a custom processor, and the other numbers look suspiciously like they may be too. There's a chance that the 393 is a comparator, but I doubt it.

There are IC's checking kits available with emulation firmware/software , i don`t have idea if its going to work for those 20 to 30 year old technology, but if such data base is available for that "ancient" technology .

You can still check with board circuit layout , can identify power pin , ground pin , crystal oscillator connection , various buses etc ,may be able to identify nature of the component and its function ,i don`t think any use it can do to todays far supperior technology but curiosity is different(great) thing .

Hi David,

your µPA2004C is a seven channel darlington array with protection diode used for control of LED or relays. You find it at www.necel.com/nesdis/image/IC-1401.pdf. It can be replaced by other parts if no longer available.

Googling "D546C" you find suppliers of those 42pin ICs who have datasheets available if you make a request.
Regards Uwe

Your C393C is a normal Comparator like LM393 from National Semiconductors or equivalents from Motorola.
Uwe