I've edited this table together for those that might have an old laptop floppy with a 26 pin connector and want to connect it to a regular 34 pin connector. Some interfaces don't use all the pins. In particular, pin 8 of the laptop floppy seems to have no equivalent on the 34 pin connector. The Dell GX-150 ribbon cable I probed had this pin unconnected.
3.5" Floppy Disk Pin Description
pin assignment pin assignment
1 GND 2 Density Select
3 GND 4 (reserved)
5 GND 6 (reserved)
7 GND 8 Index
9 GND 10 Motor Enable A
11 GND 12 Drive Sel B
13 GND 14 Drive Sel A
15 GND 16 Motor Enable B
17 GND 18 Direction
19 GND 20 Step
21 GND 22 Write Data
23 GND 24 Floppy Write Enable
25 GND 26 Track 0
27 GND 28 Write Protect
29 GND 30 Read Data
31 GND 32 Head Select
33 GND 34 Disk Change
Laptop Floppy Pin Description
pin assignment pin assignment
1 +5v 14 Step
2 Index 15 GND
3 +5v 16 Write Data
4 Drive Sel 17 GND
5 +5v 18 Floppy Write Enable
6 Disk Change 19 GND
7 Not connected 20 Track 0
8 Ready 21 GND
9 Not connected 22 Write Protect
10 Motor Enable 23 GND
11 Not Connected 24 Read Data
12 Direction 25 GND
13 Density Select 26 Head Select