NEC SX Service And Reference Manual page 99

9-8 Specifications
Parallel Printer Pin Assignments
Pin Signal
Strobe
1
Data Bit 0
2
3 Data Bit 1
Data Bit 2
4
5 Data Bit
Data Bit 4
6
Data Bit 5
7
Data Bit 6
8
Data Bit 7
9
10 Acknowledge
11 Busy
12 PE
13 Select
14 Auto Feed XT
15 Error
16 Initialize
17 Select In
18 -25 Ground