DVICEMAP Ver 2.10 (C) 1987 - Device Driver Map Program

This program is ShareWare by Stephen L. Jenkins.

It may not be modified in any way.

I retain copyright and do not put this into the public domain.

It may be freely copied, but must be distributed with this documentation.

The purpose of this program is to let you know in what order, and what
names your devices have.

This program will also show the address's, attribute, strategy
and interrupt locations for device drivers.

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DEVICE NAME
-----------

This is the name of the device. It can be used just like any file
and may be read from and written to by using this name.

If you see more then one device using the same name then the device
closest to the top of the chain gets precedent.

If the name is BLOCKxxx then the device is a block driver that
recognizes xxx number of logical drives.


ADDRESS
-------

This is where the device is physically located in memory in
segment:offset fashion.


ATTRIBUTE WORD
--------------

Bit f = 1 character device
0 block device

Bit e = 1 supports IOCTL
0 doesn't support IOCTL

Bit d = If Block Device If Character Device
1 not IBM format supports output-until-busy
0 IBM format doesn't support output-until-busy

Bit c = unknown(set to 0)

Bit b = 1 supports removable media
0 doesn't support removable media

Bit a-7 Reserved by Dos(should be 0)

Bit 6 = 1 supports Get/Set Logical Device, supports Generic IOCTL
0 doesn't support Get/Set Logical Device, doesn't support Generic IOCTL

Bit 5 Reserved by Dos(should be 0)

Bit 4 = (special CON driver bit, Int 29H)

Bit 3 = 1 current clock device
0 not current clock device

Bit 2 = 1 current NUL device
0 not current NUL device

Bit 1 = 1 current standard input device
0 not current standard input device

Bit 0 = If Character Device If Block Device
1 current standard output device (undefined)
0 not current standard output device (undefined)


STRATEGY
--------

This is the OFFSET address that DOS calls when the device is first
installed and whenever an I/O request is issued for the device.


INTERRUPT
---------
This is the OFFSET address that actually does the I/O request.
(i.e. the main module).

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If you have any other questions about device drivers some good info
can be found in the following literature:


Advanced MSDOS
by Ray Duncan
for MicroSoft Press

Running MS DOS
by Van Wolverton
for MicroSoft Press

Programmer's Problem Solver for IBM PC, XT & AT
by Robert Jourdain
for Brady (Prentice Hall Press)

IBM DOS Technical Reference
by IBM
for IBM

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Any inquiries about this program should be asked at:

National Geographic Society BBS
(202) 775-6738

Address questions to: Stephen Jenkins