IBM introduced the second generation of the 5 1/4" floppy drive in 1984 with its debut of the IBM AT PC. This floppy drive could write 1.2Mb or approximately 1.2 million characters to a floppy disk. This drive is also called a high density or HD floppy drive because it stores about 3 times the amount of data as its double density cousin.

The high density 5 1/4" drive can use either double densitiy or high density floppy disks. It is backward compatible with its predecessor the double density 5 1/4" drive.

These drives were popular in their day, but have given way to their 3 1/2" inch relatives. The need for more storage capacity pushed the drive to develop larger capacity floppy drives.