Floppy Drives

The floppy disk drive is perhaps the most stable and simplest computer component to install and maintain. What made the floppy drive so popular as a replacement for the tape drives were its speed and the ability to randomly access any files or data stored on them. The floppy disk drive is the most basic of the input/output devices and is perhaps the only component that has retained its original technology. Other than increased storage capacity, the floppy disk drive still works essentially the same (cabling and BIOS configuration) as it did when it was first developed. IBM developed the first floppy disk drives. They were used on the IBM System 370 machines that came out around 1972. These drives used 8-inch floppy disks. The 5.25-inch floppies that were familiar on the early personal computers came later. Floppies were included in personal computers before hard drives mostly because they were relatively inexpensive.

Floppy Disk Drive Basics

Floppy disk drives come in a variety of sizes and capacities; however, the cabling and BIOS configuration has remained essentially the same from the beginning. A floppy disk is made of a flexible plastic disk, coated in a magnetic material. To protect them from dust and physical damage, they are packaged in a plastic or paper case. The main advantage of using a floppy disk drive and a floppy disk is that it is a removable media. The data stored on a floppy disk can be moved from one computer to another as long as both have the same type of drives. It is a good idea to always keep two copies of any data file that you create (original and a backup). The floppy disk is the perfect media for

data backup as long as the file sizes remain small.

Floppy disks come in three physical sizes. The full-height, which are the older large 5-¼ inch drives, the half-height, which are typically the 3-½ inch drives, and the combo, which contains a 1.2 MB, 5-¼ inch and a 1.44 MB, 3-½ inch drive. Today, the 5-¼ inch floppy drive is considered obsolete, but many uses are still found for the 3-½ inch drives.

All floppy disk drives are connected to the motherboard (external data bus) using a standard cable. A standard floppy drive cable consists of a 34-wire flat ribbon cable with five connectors. Two of the connectors are 34-pin connectors used to connect to the 3-½ inch drives. Two are edge connectors (these connect to the edge of a circuit board) and are used to connect to 5-¼ inch drives. The fifth connector is used to connect to the motherboard. The cable has a seven-wire twist in lines 10 through 16. These twists separate the connectors for the “A” drive from the “B” drive. The “A” drive connectors are on the end of the cable. Even though there are four connectors, you can only use two, one for the “A” drive and one for “B” drive. It does not matter whether or not the drive is 3-½ or 5-¼ inch. The other wires carry data and ground signals.