Compaq LA36 User Manual
Page 151
D-3
Interface Information
Pin
Direction
Signal
Description
33
0 volts. Same as pins 14, 19-30.
34
Not used
35
Not used
36
Not used
IEEE 1284-B Nibble Mode signals
The following table briefly gives connector pin assignments in IEEE 1284 mode.
Pin
Direction
Signal
Description
1
To printer
HostClk
High in reverse data transfer phase
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
PtrClk
Set to low to qualify data on reverse channel
11
From printer
PtrBusy
Reverse channel: Data 3 and 7
12
From printer
AckDataReq
Reverse channel: Data 2 and 6
13
From printer
Xflag
Reverse channel: Data 1 and 5
14
To printer
Host Busy
Set to low to indicate the host can receive
data
Set to high Host Acknowledge Receipt
15
Not used
16
0 volts. Logic ground
17
Chassis ground
18
From printer
Peripheral Logic Set to high to indicate the printer is ON
High
and all signals are in valid state.
- Max output current 50 mA
19-29
0 volts. Signal ground
30
0 volts. Signal ground