ACT apricot - Page 183

PARALLEL INTERFACE
The definition of the control au tpu ts to and from the
printer and the details of the Centronics connector are
provided below.
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Centronics Connector Details
Description
Pin Description
Data strobe
19
OV
DO ...
20 OV
D1 21
OV
D2
22 OV
D3
8-bit data
23 OV
-
D4
output
24
OV
D5 25
OV
D6
26 OV
D7- 27
OV
Acknowledge (Ack)
28
OV
Busy
29
OV
Paper Empty (PE)
30
OV
Select
31 N.C.
OV
32 Fault
Unallocated Output X 33
OV
PE
OV 34
Unallocated output Y
Ground 35
N.C.
N.C. 36
N.C.
\ ~:::::::::::::::,~I)
Figure 2. Centronics Connector pin detail
Output timing signal. Used to latch the data
into the printer. Normally at logic high.
Positive edge of logic low pulse indicates
printer data is valid.
Input signal, Paper Empty. Logic high state
indicates that the printer is out of paper.
continued ....