Handshaking

Handshaking by DTR signal or X-on/X-off. The DTR signal changes to mark - meaning the printer is not ready to receive data - when the number of bytes free in the input buffer goes down to 256. The signal changes to space - meaning that the printer is now ready - when the number of bytes in the input buffer rises to 528.

Error handling

A * character is printed if a parity error is detected. All other errors are ignored.

Connector

D-sub 25-pin connector

In this table, the direction of signals is given relative to the printer.

Initialization

There are the three ways that the printer can be initialized (returned to a fixed set of conditions).

Hardware initialization

Software initialization

When the power is turned on

When the printer receives an INIT signal at the parallel interface (pin 31 goes LOW).

Software sends the ESC @ (initialize the printer) command.

Technical Specifications

A-13