 The 25-MHz model was available with either a 120-MB or 240-MB IDE hard disk drive, and the 33-MHz model had a 240-MB IDE hard disk drive.Both models had a built in 3.5" 1.44-MB floppy disk drive.All models shipped with MS-DOS 6.2, with Compaq's unique set of DOS extensions for power management, configuration and model specific help.