5-1
CHAPTER 5 INTERFACE INFORMATION

5.1 Overview

The PrintPartner 20W printer communicates with the host through two parallel interfaces and a serial interface or an
optional interface. The printer automatically selects the interface proper to the occasion. This chapter describes the
parallel and serial interfaces. For locations of the parallel and serial interface connectors and the optional interface’s
slot, see Figure 1.3.

5.2 Parallel Interface (IEEE 1284-B Connector)

The parallel interface is a bidirectional Centronics interface (nibble mode of the IEEE 1284 standard is supported).

5.2.1 Hardware requirements

Signal levels: TTL-compatible
0.0 to +0.4 V for low-level
+2.4 to +5.0 V for high-level
Input circuit: SN74LS14 or equivalent
Figure 5.1 shows the parallel interface input circuit.
+5 V
1 k
100
1000 pF
+5 V
1 k
Data Strobe
Input Prime
Data 1-8
(Auto Feed XT)
(Select In)

Figure 5.1 Parallel interface input circuit