Very complex controller board for the PIC16C65,
Serial interfaces, RS232, I²C, PWM all by couplers,
Parallel I/O via optocouplers,
DALLAS watch with I²C,
connectable by RJ11 resp. RJ45 plugs,
two 5 volt power supplies integrated.
Dimension 1:1 as shown in the Data sheet
originally used for Paul ventilation control
Board without devices, but can be supplied.