Category : C++ Source Code
Archive   : NOPAUSE.ZIP
Filename : NOPAUSE.DOC

NOPAUSE.CPP and NOPAUSE2.CPP
By Thomas Astin CIS: 73407,3427 Prodigy: RNVN08A
(C) Copyright 1991. All rights reserved.

Introduction
------------
This code demonstrates how to "disable" the pause/lock feature provided on
most 286/386 class machines supporting a 101/102 keyboard. When Pause is
pressed the BIOS loops until any other key is pressed thereby allowing the
user to suspend any program currently running.

NOPAUSE and NOPAUSE each demonstrate a way to disable the Pause feature. The
word "disabled" is used loosely because the Pause key is not actually
disabled. Either the Pause key scan codes are kept from the BIOS or the BIOS
data area containing a Pause/Lock bit is constantly cleared. Due to limited
testing on multiple machines it is hard to say if this code will behave
correctly on all machines. Please see notes in source code for further
information.

Method #1 - NOPAUSE.CPP
-----------------------
NOPAUSE demonstrates by way of intercepting keyboard hardware int 0x09.


Method #1 - NOPAUSE.CPP
-----------------------
NOPAUSE2 demonstrates by way of intercepting clock tick interrupt 0x1C. The
code in the intercepting handler clears a Pause/Lock bit located in the BIOS
data area. NOTE: This worked on the testing machine because it was known that
the Pause/Lock loop in the testing machine's bios tested the Pause/Lock bit
and droped out of the loop if the bit was clear. This may not work the same on
other machines.