C H A P T E R 1

LaserWriter Select 310 Hardware

Figure 1-3 shows the pin designations for the Centronics parallel connector and Table 1-3 lists the signal descriptions. Figure 1-4 shows the timing requirements for the Centronics interface.

Figure 1-3

A Centronics parallel connector

Pin 18

 

 

 

Pin 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Pin 36

 

 

Pin 19

Table 1-3

Signal descriptions for a Centronics parallel port

 

 

 

 

 

 

 

Pin

 

 

 

 

number

Signal name

I/O

Description

1

 

 

 

/PSTROBE

I

Strobe for parallel input data

2

 

 

 

DATA 0

I

Data input bit 0

3

 

 

 

DATA 1

I

Data input bit 1

4

 

 

 

DATA 2

I

Data input bit 2

5

 

 

 

DATA 3

I

Data input bit 3

6

 

 

 

DATA 4

I

Data input bit 4

7

 

 

 

DATA 5

I

Data input bit 5

8

 

 

 

DATA 6

I

Data input bit 6

9

 

 

 

DATA 7

I

Data input bit 7

10

 

 

 

/PACK

O

Handshaking output signal; printer uses it to

 

 

 

 

 

 

acknowledge receipt of parallel data

11

 

 

 

PBUSY

O

Busy output signal; indicates that a /PSTROBE

 

 

 

 

 

 

signal has been received, but /PACK has not

 

 

 

 

 

 

yet been given

12

 

 

 

POUT

O

Paper out; an output error signal; indicates the

 

 

 

 

 

 

printer has run out of paper

13

 

 

 

Tied high

–

This select line is tied high so the LaserWriter

 

 

 

 

 

 

Select 310 printer is always selected

14, 15, 16

Not connected

–

These lines are not connected

17

 

 

 

CHASSIS

–

Chassis ground

 

 

 

 

GROUND

 

 

 

18

 

 

 

Not used

–

Not used

6

Communication Ports

Page 18
Image 18
Apple 310 manual Pstrobe