User's Manual

Table Of Contents

Interface

D-7

User's Manual

INTERFACE INFORMATION

Data Transmission Timing

In unidirectional mode (conventional Centronics interface), this printer

guarantees the received data when the Data and Data Strobe signals from the

computer have the following timing with respect to the Busy and

Acknowledge signals from the printer.

➤

T5 T6

T1, T2, T3 > 1 µs

T4 < 1 µs

0 µs < T5 < 3 µs

2 µs < T6 < 6 µs

Data 1 to Data 8

Data Strobe

BUSY

Acknowledge

T2 T3

In bidirectional mode (nibblemode), this printer can send data to the

computer. Data is sent in units of four bits (nibble) using four output signal

lines as data paths. The following outlines one byte of data sent during

reverse data transfer phase in nibble mode.

Data Available (*)

X Flag

Ack Data Req

Printer Busy

Host Busy

(from CPU)

Printer Clock

Data bit 4

Data bit 5

Data bit 6

Data bit 7

Data bit 0

Data bit 1

Data bit 2

Data bit 3

1284 Active

(from CPU)

* Data Available is assigned for the cable.