M5L8042-153P

Custom Mask-Programmed 8-Bit Universal Peripheral Interface (UPI-41) Microcontroller, containing a 12MHz internal core clock, 1KB of factory-calibrated program ROM, and a dedicated 8-bit asynchronous data bus interface designed primarily to manage keyboard scanning and system command routing, housed in a standard 40-pin through-hole plastic DIP package. Manufactured by Mitsubishi Electric.