Specifications

CHAPTER 1
Introduction to the LaserWriter 16/600 PS Printer
8
Communication Ports
Note
In Table 1-3, inputs and outputs are referenced to the printer. This means
that an input (I) is a signal sent from the host computer to the printer,
and an output (O) is a signal sent by the printer to the host.
◆
Table 1-3 Signal descriptions for the Centronics parallel port
Pin
number Signal name I/O Description
1 /STROBE (HostClk) 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 /ACK (PtrClk) O Handshaking output signal; printer
uses this signal to acknowledge receipt
of parallel data
11 BUSY (PtrBusy) O Busy output signal; indicates that a
/STROBE signal has been received, but
that /ACK has not yet been given
12 PAPER ERR
(AckDataReq)
O Paper error, an output error signal;
indicates the printer has run out
of paper
13 SELECT (Xflag) O Printer select line; driven high to
indicate the LaserWriter 16/600 PS
printer is online
14 /AUTOFEED
(HostBusy)
I
15, 34 Not connected – These lines are not connected
17 GND – Chassis ground
18, 33, 35 Tied high – Not used, tied high
16, 19-30 GND – Signal ground
31 INPRIME (nInit) I Reset signal; host CPU asserts this
signal to cancel the current job on
this port
continued