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From: janices@tekig5.UUCP (Janice Singer)
Newsgroups: net.micro.pc
Subject: Summary about DOS and Interrupts
Message-ID: <84@tekig5.UUCP>
Date: Wed, 8-May-85 16:51:27 EDT
Article-I.D.: tekig5.84
Posted: Wed May  8 16:51:27 1985
Date-Received: Fri, 10-May-85 01:06:45 EDT
Organization: Tektronix, Beaverton OR
Lines: 30



In the replies to my queries about DOS and Interrupts, the following
appears to be true:

1)  You can use DOS function calls from within a user-defined interrupt
vector.  I have tried this myself by redefining INT 05H to output a
character to the screen (INT 21H - function 02H).  The catch is that
this only works when running an application.  IE if I am running Lotus
and I press Shift-PrtSc, a character is output, then I return to Lotus.
If I am at the command line (eg. A> ) and I press Shift-PrtSc, a
character is output to the screen, but I get lost in DOS hyperspace and
never return to the command line.  In fact I have to turn the machine 
off to continue.

2) It appears that there are no available listings of DOS.

3) The one consensus in all of my replies is that both IBM and MicroSoft
are reluctant to help users find answers to these types of questions.  I
have posted another article about a service called DIAL and hopefully
will get some replies.  One thing that I found out is that MicroSoft has
a service called TAR (Technical Assistance Request).  This service is in
conjunction with DIAL, but is FREE !!!!!  I am waiting for info, and if
it is worthwhile will post to the net.  It seems the best place to look
for technical assistance is the net.

To all who replied to me, THANKS

Janice Singer
Tektronix