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7.2 Parallel Interface
Connector Pin Assignment
Item Specification
Method Centronics
Data transfer rate 1000 to 6000 cps
Synchronization method External supply strobe pulse
Handshaking By ACK and BUSY signals
Logic level TTL-compatible
Pin No. Signal Name IN/OUT Function
1 STROBE IN Normally HIGH. Data reading starts after this signal
becomes LOW.
2 ~ 9 DATA 1 ~ 8 IN Data. HIGH for “1”, LOW for “0”.
10 ACK OUT Turned ON when data acquisition is complete.
11 BUSY OUT Reception of data is possible when this signal is LOW;
reception is not possible when HIGH.
12 PAPER OUT OUT Becomes HIGH when no paper is inserted.
13 SELECTED OUT Becomes HIGH when the printer goes on line.
14 ~ 15 N/C Not used
16 SIGNAL GND Signal ground
17 CHASSIS GND Printer frame ground
18 +5 V +5 V for external equipment (50 mA max.)
19 ~ 30 TWISTED
PAIR RETURN Return signal for various signals
31 RESET IN Initializes the printer when LOW.
32 ERROR OUT Becomes LOW when the printer cannot function.
33 EXT GND Ground terminal for external equipment
34 ~ 35 N/C Not used
36 — Always HIGH