Phil Storrs PC Hardware book

Floppy disk drive hardware

A 3.5 inch floppy disk drive uses a 34 pin header (pin) connector to the interface

A modern 5.25 inch Floppy Disk Drive uses a direct drive motor to rotate the floppy disk media. 5.25 inch drives use a 34 wire edge connector to connect to the Floppy Disk Drive Interface, and a large 4 pin power connector to supply +5 volt and +12 volt to the drive.

The motor rotates the disk media at a constant speed.

• Normal (Double Density) disks are rotated at 300 RPM
• High Density (Quad Density) disks are rotated at 360 RPM

A floppy disk drive interface cable has a 34 pin header socket on the interface end

• The A: drive connectors are at the other end of the cable and usually have a twist to transpose the wires to pins 10 to 16.
• Most floppy drive cables have both edge connectors (for 5.25 inch drives) and header connectors (for 3.5 inch drives) in both drive positions on the cable.