Microcom 814M Operators Manual User Manual
Page 39
35
6.2.3 Parallel Interface Signals
Note:
− H stands for host computer terminal and P stands for printer terminal.
− Parallel Interface signals use TTL voltages. When it is used, please make sure both the rise and drop
time of host computer terminal is no longer than 0.5us.
− When data transfers, the host computer should not ignore the busy signal, or else the print data may
be lost.
− The length of parallel interface connection wire should be as short as possible.
Pin No.
Source
Compatible mode
1
H
nStrobe
2
H
Data 0 (Least Significant Bit)
3
H
Data 1
4
H
Data 2
5
H
Data 3
6
H
Data 4
7
H
Data 5
8
H
Data 6
9
H
Data 7 (Most Significant Bit)
10
P
nAck
11
P
Busy
12
P
Perror
13
P
Select
14
H
nAutoFd
15
Not Defined
16
Logic Ground
17
Chassis Ground
18
P
Peripheral Logic High
19
Signal Ground (nStrobe)
20
Signal Ground (Data 0)
21
Signal Ground (Data 1)
22
Signal Ground (Data 2)
23
Signal Ground (Data 3)
24
Signal Ground (Data 4)
25
Signal Ground (Data 5)
26
Signal Ground (Data 6)
27
Signal Ground (Data 7)
Table 6-3 Parallel Interface Signals Definition