21Nterface Specifications; Parallel Interface (Forward Channel) - Epson 2070 - LQ B/W Dot-matrix Printer Service Manual

1.3.2 Interface Specifications
This
printer provides a bidirectional 8-bit parallel interface and a Type B optional interface slot,
standard.
1.3.2.1 Parallel Interface (Fotward Channel)
Transmission mode
Adaptable connector
Synchronization
. Handshaking
Signal level
Table 1-31 Pin Assignments for Forward Channel
Return
Pin Signal
No. Name
STROBE
2
3
4
5
6
7
8
9
ACKNLG
10
11 BUSY
, 12 PE
13
SLCT
14
AFXT
31
32 ERROR
36
18
Logic H
35
17 Chassis
16,33,
19-30
15,34
NC
8-bit parallel, IEEE-P1284, compatibility mode
57-30360 (Amphenol) or equivalent
STROBE
BUSY and ACI@lLG signals
In IOut
Strobe pulse. Input data is latched at falling edge of the signal
19 In
In Parallel input data to the printer
20
21 In
22 In
23 In
24
In
25 In
26
In
27 In
This signal (negative pulse) indicates the printer has received
out
28
data and is ready to accept more data.
This signal's HIGH level means the printer is not ready to
29 out
accept data.
This signal's HIGH level means the printer has a paper-out
out
28
error.
out
28
Always HIGH when the printer is powered on.
Not used.
In
30
This signal's negative pulse initializes printer.
30 In
This signal's LOW level means the printer is in an error state.
29
out
Not used.
30 In
----
o u t This line is pulled up to + 5 V through 3.9KQ resistor.
----
Out
This line is pulled up to +5 V through 3.3KQ resistor.
----
-–- Chassis GND.
Signal
---- ---
---- ---
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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