Path: utzoo!attcan!uunet!samsung!olivea!orc!inews!iwarp.intel.com!ogicse!uwm.edu!rpi!masscomp!peora!tarpit!bilver!dandrews
From: dandrews@bilver.uucp (Dave Andrews)
Newsgroups: comp.os.msdos.programmer
Subject: Re: TSR PROGRAMMING PROBLEM
Message-ID: <1991Jan31.144908.18304@bilver.uucp>
Date: 31 Jan 91 14:49:08 GMT
References: <5369@trantor.harris-atd.com> <2168@njitgw.njit.edu> <1991Jan30.050646.7067@bronze.ucs.indiana.edu>
Organization: W. J. Vermillion - Winter Park, FL
Lines: 22

In article <1991Jan30.050646.7067@bronze.ucs.indiana.edu> yawei@bronze.ucs.indiana.edu (mr. yawei) writes:
>To be exact (and make my ends covered), DOS uses 3 stacks for its
>various function calls. So if you stretch it, you can re-enter DOS
>for a miximum of 3 times. A few other glitches (restrictions) reduce
>the maximum to 2 times. 
>
>DOS itself does not detect that you are trying to trash its stack,
>so it takes elaborate programming to ensure that the re-entrancies
>are safe. I am not going to elaborate how to do this as it probably
>will take a couple of chapters. :-)

It will do everyone around here some good to run, don't walk,
to the nearest technical bookstore and purchase the following
amazing book:

   _Undocumented DOS_
   Andrew Schulman, Raymond J. Michels, Jim Kyle,  
   Tim Paterson, David Maxey and Ralf Brown
   Addison Wesley, 1990, 694 pages
   ISBN 0-201-57064-5

- Dave