Category : Pascal Source Code
Archive   : INFOS155.ZIP
Filename : PAGE_12.INF

This page lists all the device drivers in use. Some are internal to DOS,
and others are loaded with DEVICE= lines in CONFIG.SYS.

The information shown is:

Device: The name of the driver, if given.

Units: For a block device, the number of units inside of it.

Header: The address where the driver resides.

Attributes: There are 16 bits that define what the driver does. Numbering
left to right, with left being 15:

15: 1 = character device, 0 = block device
14: 1 if IOCTL (special commands) are supported
13: if a block device, then 1 means to use the boot sector to
get information, 0 to use media ID byte.
if a character device, then 1 means you can output till
busy
12: unused (0)
11: 1 if open/close/removable media is supported
10: unused (0)
09: unused (0)
08: unused (0)
07: unused (0)
06: 1 if generic IOCTL and get/set logical drive supported
05: unused (0)
04: 1 if the CON device, and fast output (Int 29h) supported
03: 1 if the CLOCK$ device
02: 1 if the NUL device
01: if a block device, then 1 means 32-bit sectors supported
if a character device, then 1 means it is standard output
00: 1 if device is standard input

Strategy: This is the address used to setup a call.

Interrupt: The address called to execute a command.

Some common driver names:

EMMXXXX0: an EMS driver
XMMXXXX0: an XMS driver
\MMXXXX0: EMS driver disabled under Windows 3 (which supplies its own.)
SMARTAAR: Disk cache (SmartDrive)
SETVERXX: SETVER.EXE