Sunday June 30 1996 08:05, Jason Wright wrote to Peter Watney:

 PW>> In order to completely disable Ctrl-Break you have to change the copy
 PW>> of Command.Com that your application happens to be using at the time.
 PW>> The reason is that for a number of operations Pascal is using DOS, and
 PW>> DOS has no way to disable Ctrl-Break (legally), so whenever your

 JW> 'break=off' in config.sys?  Hmmm, or does that only stop some of the
 JW> checking???....

It is a long time since I played with it, but memory suggests that the
config.sys setting controls whether or not Ctrl-Break works instantly or
asks you the question first.  There is no setting which stops the question
being asked if 'break=off'.  The way in which I inhibited it was to find
the address in Command.com where the question is asked, and make it answer
'no' whether you pressed a 'y' or a 'n'.

This has the disadvantage that the address in Command.com is different,
depending on which version of DOS one was using, so the solution would only
work for the 'home' computer set to look at the doctored command.com.

 PW>> Pascal application is loading, or is temporarily passing control to
 PW>> DOS, even though you have SetCBreak set to false DOS will intercept
 PW>> the key stroke and interpret it.

 JW> I can't exit any of my apps using ctrl+c\ctrl break.

In that case your apps are not passing control to DOS at any stage.

I was constructing a menu program, which for security reasons I wished to
ensure the user could not access DOS.

The jokers/hackers in the High School had been amusing themselves by
wrecking the directories/files in the computers.

The menu was designed to prevent access to DOS.  The fdd was restricted to
B drive.  Any application that passed control to DOS had that facility
disabled.

It did work for over a year so that vandalism of the directories stopped
for that time.

Regards,
Peter

--- GEcho 1.00