AT&T 3B2/300 Technical Reference Manual page 757

- - - - - - - - - - - - - - - - A p p e n d i x : CONNECTOR AND CABLING INFORMATION
20-PIN DAT A 1 CONNECTOR, J3
PIN DESCRIPTION
1 DRIVE SELECTED (DSD[O])
2 GROUND
3 NOT USED
4 GROUND
5
NOT USED
6
GROUND
7 CONNECTOR COMMON (J1P16)(J2P7)
8
GROUND
9 NOT USED
10
GROUND
11
GROUND
12 GROUND
13 +MFM WRITE DATA (MFMOPl)
14 -MFM WRITE DATA (MFMONl)
15 GROUND
16 GROUND
17 +MFM READ DATA (MFMIPl)
18
-MFM READ DATA (MFM!Nl)
19
GROUND
20 NOT USED
LEGEND:
MFM
NC
Modified Frequency Modulation
No Connection
FUNCTION
INPUT
GROUND
NC
GROUND
NC
GROUND
GROUND
NC
GROUND
GROUND
GROUND
OUTPUT
OUTPUT
GROUND
GROUND
INPUT
INPUT
GROUND
NC
CONNECTOR AND CABLING INFORMATION B-175