NCR 7458 - Manual (Page 89)

Chapter 3: Hardware Service 3-65
Flexible Diskette (CN18)
Signal Name Pin Pin Signal Name
Ground 1 2 DRVDEN0
Ground 3 4 Reserved
Key 5 6 DRVDEN1
Ground 7 8 Index#
Ground 9 10 Motor Enable 1#
Ground 11 12 Drive Select 0#
Ground 13 14 Drive Select 1#
Ground 15 16 Motor Enable 0#
Ground 17 18 DIR#
Ground 19 20 STEP#
Ground 21 22 Write Data#
Ground 23 24 Write Gate#
Ground 25 26 Track 0#
Ground 27 28 Write Protect#
Ground 29 30 Read Data#
Ground 31 32 HDSEL
Ground 33 34 DSKCHG Change#