Compaq LA36 User Manual
Page 150
D-2
Interface Information
Centronics Compatible signals
Pin
Direction
Signal
Description
1
To printer
STROBE L
STROBE pulse low to read data
A strobe low signal will raise BUSY line to
high.
2
To printer
DATA BIT 1
These signals are the 1st to the 8th bits of
3
To printer
DATA BIT 2
parallel data.
4
To printer
DATA BIT 3
5
To printer
DATA BIT 4
These signals are active high for a logical 1.
6
To printer
DATA BIT 5
7
To printer
DATA BIT 6
8
To printer
DATA BIT 7
9
To printer
DATA BIT 8
10
From printer
ACKNLG L
ACKNLG pulse low indicates data received
and ready to receive more data.
Sent at power up or after INIT sequence.
11
From printer
BUSY H
high indicates the printer can not
receive data (buffer full). BUSY high occurs
when paper is out, an INIT is received, the
printer is offline, or an error condition exists.
12
From printer
PE H
PAPER END high signal indicates paper out.
13
From printer
SLCT H
A high signal indicates the printer is in the
select state.
SLCT L
Low signal occurs when printer is de selected
or an error condition exists.
14
Not used
15
Not used
16
0 volts. Logic ground.
17
Chassis ground.
18
+ 5V. Maximum output current is 50 mA.
19-29
TWP returns
0 volts. All at logic ground.
30
INIT ground
0 volts
31
To printer
INIT L
INIT low resets the printer to its initial state
and clears the buffer.
Printer must see a pulse > 25 microseconds.
32
From printer
ERROR L
This signal is low when the printer is out of
paper, not selected, or in an error state.