Apple LaserWriter Select 310 Printer User Manual
Page 18
C H A P T E R 1
LaserWriter Select 310 Hardware
6
Communication Ports
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
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
GROUND
–
Chassis ground
18
Not used
–
Not used
Pin 18
Pin 36
Pin 1
Pin 19