Floppy 40-pin

Signals and voltages are transferred between the system board and the diskette drives by a cable or printed circuit board. The printed-circuit board provides a 2- by 20-pin card edge connector for each diskette drive, with a locator key between pins 34 and 36. The cable interface provides a 2 x 17-pin header connector to each diskette drive, with a locator key below pin 17. ) The following figures show the signals and DC voltages for each diskette drive connector type:

Pinout

40-Pin Card-Edge connector

Pin Signal     Pin Signal
 1  Ground      2  -High Density Select
 3  Reserved    4  Reserved
 5  Ground      6  Reserved
 7  Ground      8  -Index
 9  Ground     10  Reserved
11  Ground     12  -Drive Select
13  Ground     14  Reserved
15  Ground     16  -Motor Enable
17  Ground     16  -Direction In
19  Ground     20  -Step
21  Ground     22  -Write Data
23  Ground     24  -Write Enable
25  Ground     26  -Track 0
27  Ground     28  -Write Protect
29  Ground     30  -Read Data
31  Ground     32  -Head 1 Select
33  Ground     34  -Diskette Change
35  Ground     36  Ground
37  Ground     38  +5VDC
39  Ground     40  +12VDC

Contributors

• Iggy Drougge
• Joakim Ögren

Sources

• Floppy Drive Pinouts by Louis F. Ohland III
• PS/2 3.5-inch Diskette Drives Technical Reference (S42G-2194-00), 2nd Ed., Oct 1992, pages 10-12.