Compaq P5000 Series Centronics Parallel Interface, Centronics Interface Signals, Input Signals

Chapter 5 Centronics Parallel Interface

Centronics Parallel Interface

The Centronics interface enables the printer to operate with controllers designed for buffered Centronics printers. The length of the data cable from the host computer to the printer must not exceed 15 feet (5 meters).

Table 12. Centronics Interface Connector Pin Assignments

Input Signals		Output Signals		Miscellaneous
Signal	Pin	Signal	Pin	Signal	Pin
DATA LINE 1	2	ACKNOWLEDGE	10	CHASSIS GROUND	17
Return	20	Return	28
DATA LINE 2	3	ONLINE	13	GROUND	30
Return	21	Return	28
DATA LINE 3	4	FAULT	32	Spares	14
Return	22	Return	29
DATA LINE 4	5	PAPER EMPTY	12	No Connection	34,35,
Return	23	Return	28		36
DATA LINE 5	6	BUSY	11	+5 Volts	18
Return	24	Return	29
DATA LINE 6	7
Return	25
DATA LINE 7	8
Return	26
DATA LINE 8	9
Return	27
DATA STROBE	1
Return	19
PAPER INSTRUCTION	15
Return	29
PRIME	31
Return	30

Centronics Interface Signals

The Centronics interface signals between the host computer and the printer are defined as follows:

Data Lines 1 through 8. Provide eight standard or inverted levels from the host that specify character data, plot data, or a control code. Data Line 8 allows access to the extended ASCII character set. You may enable or disable this line via the Data Bit 8 parameter on the Centronics submenu (page 107).

Data Strobe. Carries a low true, 100 ns minimum pulse from the host that clocks data into the printer.

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