Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!linus!decvax!harpo!seismo!hao!hplabs!sri-unix!"GlasserAlan"@LLL-MFE.ARPA
From: "GlasserAlan"@LLL-MFE.ARPA@sri-unix.UUCP
Newsgroups: net.micro.pc
Subject: Control-Break
Message-ID: <4300@sri-arpa.UUCP>
Date: Tue, 16-Aug-83 20:56:00 EDT
Article-I.D.: sri-arpa.4300
Posted: Tue Aug 16 20:56:00 1983
Date-Received: Sun, 21-Aug-83 05:46:22 EDT
Lines: 15

Can anyone offer me advice about a problem I'm having with BIOS and
DOS interrupts?  I've written a Tektronix emulation program in assembly
language.  It works fine except for one minor problem.  If a plot is
cut off with a CTRL-BREAK, the program remains in graphics mode and
doesn't return to alpha.

I thought I could overcome this by replacing BIOS interrupt 1B by my
own interrupt routine, which would reset to alpha mode and then exit
to the original interrupt.  In fact, this is what I did with BIOS
interrupt 10 and DOS interrupt 21 function 9 to get the Tektronix
emulation working.  For some reason, it doesn't work with 1B and 23.
Any ideas why?  Also, how can I enable a CTRL-BREAK in an arbitrary
program?

                      Alan Glasser (glasser@lll-mfe)