Parallel Interface (Reverse Channel); Table 1-33 Pin Assignments For Reverse Channel - Epson 2070 - LQ B/W Dot-matrix Printer Service Manual

1.3.2.2 Parallel Interface (Reverse Channel)

Transmission mode
. Adaptable comector
Synchronization
. Handshaking
Signal level
. Data transmission timing

Table 1-33 Pin Assignments for Reverse Channel

Pin Signal
Name
No,
2
3
4
5
6
7
8
9
10
PtrBusy I
11
12
DataBit-2, 6
13
DataBit-l, 5
14 HostBusy
31
DataAvail /
32
DataBit-O, 4
36 1284-Active
18 Logic H
35 +5 v
17
Chassis
16,33,
GND
15,34
NC
57-30360 (Anphenol) or equivalent
Refer to the IEEE-P1284 Specification
Refer to the IEEE-P1284 Specification
Refer to the specification
In/Out
19 In Host clock signal.
20 In Parallel input data to the printer
21 In
22 In
23 In
24 In
25 In
26 In
27 In
28 o u t
Printer clock signal.
Printer busy signal and reverse channel transfer of data
29
o u t
bits 3 or 7
Acknowledge data request signal and reverse channel
28 o u t
transfer of data bits 2 or 6
X-flag signal and reverse channel transfer of data bits 1
28 o u t
or 5
In Host busy signal.
30
Not used.
In
30
Data available signal and reverse channel transfer of
29 o u t
data bits O or 4
In 1284 active signal.
30
- - -
o u t This line is pulled up to + 5 V through 3.3K Q resistor.
o u t This line is pulled up to +5 V through 3.3K Q resistor.
- - -
Chassis GND.
Signal GND.
. . -
. . -
Not connected.
Product Description
Function Description
bit O: LSB
bit 1
bit 2
bit 3
bit 4
bit 5
bit 6
bit 7: MSB
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