Parallel Interface - Epson MX-80 Operation Manual

1.3. Power circuit
The power circuit generates 5V DC for the logic circuit, and 24V DC to energize
the solenoids of the print head and two stepper motors.
1.4. Printer initialization
Printer initialization is accomplished in either of the two ways described below.
(1) Initialization takes place automatically each time the primary AC power source
is interrupted and reapplied (i.e., by turning the Power Switch off and on).
(2) Initialization may be initiated remotely by activating the INIT signal to the
parallel interface connector. This line should be driven by a TTL driver or its
equivalent.