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Apple LaserWriter Select 310 Printer User Manual

Page 19

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C H A P T E R 1

LaserWriter Select 310 Hardware

Communication Ports

7

Figure 1-4

Timing for a Centronics interface

19-30

SIGNAL
GROUND

Signal ground

31

Not connected

This line is not connected

32

/FAULT

O

Fault signal; asserted if there is a printer
problem

33-36

Not connected

These lines are not connected

NOTE

Inputs and outputs are referenced to the printer. An input (I) signal is

sent from the host computer to the printer, and an output (O) signal is sent from
the printer to the host.

Table 1-3

Signal descriptions for a Centronics parallel port (continued)

Pin
number

Signal name

I/O

Description

Data

/PSTROBE

PBUSY

/PACK

a. Data setup time before PSTROBE on
b. PSTROBE on pulse width
c. Data hold time after PSTROBE off
d. PSTROBE on to PBUSY on
e. Duration of PBUSY on (printer on line)
f. PBUSY off to /PACK on
g. /PACK on pulse width

0.5µsec
1.0µsec
0.5µsec
0.0µsec

10.0µsec

0.0µsec
1.5µsec

2.5µsec

500µsec

1.0µsec

10.0µsec

Timing specification

Min. value

Typical value

Max. value

a

c

b

d

f

e

g