Apple LaserWriter Select 310 Printer - 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