17
Chapter 2
External Connectors
Parallel Port
a. All data bits are sent to a printer in an 8-bit parallel format.
b. The signal is active low.
8
Clear to send
9
Ring indicator
Table 2-3. Parallel Port Signal Description
Pin Number
Signal Description
Pin Number
Signal Description
1
Strobe5
10
Acknowledge
b
2
Data bit 06
11
Busy
3
Data bit 1
a
12
Paper end
4
Data bit 2
a
13
Select
5
Data bit 3
a
14
Auto line feed
b
6
Data bit 4
a
15
Error1
7
Data bit 5
a
16
Initialize printer
b
8
Data bit 6
a
17
Select in
b
9
Data bit 7
a
18-25
Signal ground
Table 2-2. Serial Port Signal Description
Pin Number
Signal Description
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
