IOCtl interfaces are generally used by the file system utility applications such as FORMAT and CHKDSK to prepare or access media when a file system is not operating. The interfaces also perform operations that query or change hardware-specific characteristics of a device.
Category 08h IOCtls apply to a single drive letter or partition. Most file system utility programs access disks using this IOCtl category.
Category 09h IOCtls apply to the entire physical device. In other words, these IOCtls ignore any partitioning scheme that may be present on the drive. Partitioning utility programs such as FDISK and FDISKPM use this IOCtl category to set up a disk partitioning scheme.
The OS2DASD Device Manager supports the IOCtls shown in the following table:
┌──────────┬──────────┬────────────────────────────────────────┐ │Category │Function │Purpose │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │22h │Create Alias Drive Letter │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │40h │Lock/Unlock/Eject Media │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │43h │Set Drive Parameters │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │44h │Write Track │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │45h │Format/Verify Track, Multitrack Verify │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │5Dh │Stop/Start Diskette Controller │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │60h │Read Diskette Media Type Switches │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │63h │Get Drive Parameters │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │64h │Read Track │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │65h │Verify Track │ ├──────────┼──────────┼────────────────────────────────────────┤ │08h │66h │Get Drive Status - Locked/Unlocked/Ready│ ├──────────┼──────────┼────────────────────────────────────────┤ │09h │44h │Physical Volume - Write Track │ ├──────────┼──────────┼────────────────────────────────────────┤ │09h │63h │Physical Volume - Get Drive Parameters │ ├──────────┼──────────┼────────────────────────────────────────┤ │09h │64h │Physical Volume - Read Track │ ├──────────┼──────────┼────────────────────────────────────────┤ │09h │65h │Physical Volume - Verify Track │ └──────────┴──────────┴────────────────────────────────────────┘