Appendix F

The Parallel and Serial Interfaces

The LQ-800/1000 printers have both parallel and serial interfaces to communicate with the computer; this appendix describes these inter- faces.

Parallel Interface

Connector pin assignments and a description of respective interface signals are shown in Table F-1.

Table F-1. Pins and signals

Signal

Return

 

 

Direc-

 

Description

Pin

Pin

Signal

 

tion

 

1

19

 

 

IN

 

pulse to read data in Pulse

STROBE

 

STROBE

 

 

 

 

 

width must be more than 0.5

 

 

 

 

 

microseconds at the receiving terminal.

2

20

DATA 1

 

IN

These signals represent information

3

21

DATA 2

 

IN

of the 1st to 8th bits of parallel

4

2 2

DATA 3

 

 

data, respectively Each signal is

5

23

DATA 4

 

IN

at HIGH level when data is logical

6

24

DATA 5

 

IN

1 and LOW when it is logical 0.

725 DATA 6

8

26

DATA

7

IN

9

2 7

DATA

8

IN

1028 ACKNLG OUT Approximately 12-microsecond pulse. LOW indicates that data has been received and that the printer is ready to accept more data.

11

29

BUSY

OUT

A HIGH signal indicates that the printer

 

 

 

 

cannot receive data. The signal goes

 

 

 

 

HIGH in the following cases:

 

 

 

 

1) During data entry (ea.char.time)

 

 

 

 

2)

During printing

 

 

 

 

3)

When Off-Line

 

 

 

 

4)

During printer-error state

F-1