From: u7711501 AT bicmos DOT ee DOT nctu DOT edu DOT tw (Jih-Shin Ho)
Newsgroups: comp.os.msdos.djgpp
Subject: handle kbd & mouse without locking memory
Date: 11 Mar 1997 08:26:12 GMT
Organization: Computer Center, National Chiao-Tung University, Taiwan
Lines: 26
Message-ID: <5g34v4$egl@ccnews.nctu.edu.tw>
NNTP-Posting-Host: bicmos.ee.nctu.edu.tw
NNTP-Posting-User: u7711501
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

Hi:
  Do you know how DJGPP handles CTRL-C signal ? If you don't, please read
  DJGPP faq. I use the same way to handle keyboard and mouse, and it works
  fine in plain DOS. With this method, I don't need to lock any memory, but
  I need to hack the library source.

  However, this method doesn't work under Win95. I always get the 'protection
  fault' message from DPMI server, NOT from DJGPP exception handler.
  It seems that the DPMI server in win95 will touch something in user stack.
  The selector for stack is equal to data selector whose size is changed to
  4k only after kbd, mouse interrupt occurs (this is how DJGPP handles CTRL-C
  signal). So DPMI server reports GPF.
  If I change SS to ___djgpp_ds_alias which is always valid, I get NO MORE
  GPF. I don't know if this is bug in win95 DPMI server.

  This is just my little experience. Any comment is wlecome.

-- 
  Jih-Shin Ho, National Chiao Tung University
  u7711501 AT bicmos DOT ee DOT nctu DOT edu DOT tw

  DISPLAY -- universal image/movie viewer, converter, and indexer for DOS.
  Package name  : disp???a.zip, disp???b.zip. ??? is version number.
  Official site : NCTUCCCA.edu.tw:/Graphics/Display.
  Other site    : oak.oakland.edu:/pub/simtelnet/msdos/graphics.
  WWW page      : http://bicmos.ee.nctu.edu.tw/