1.1 Partitions

Early version of DOS only supported up to four partitions per disk drive. This was because they had to fit the partition table and initial boot program had to fit into a single 512 byte sector. Twenty years later things still work pretty much the same, except for one new change. One of the four partitions can be an extended partition which tells where more partitions can be found. MS DOS calls partitions that live within and extended partition Logical Drives. The only terminology I will use is in this text is partition, because all partitions are created equal.

The fdisk program provides a way to add and delete partitions, as well as modify the system indicator byte and bootable flag. However, for more advanced editing, a hex editor or the Norton DiskEdit program are much better solutions.