From:	"Mr A Appleyard" <MCLSSAA2 AT fs2 DOT mt DOT umist DOT ac DOT uk>
Organization:	Materials Science Centre
To:	DJGPP AT delorie DOT com
Date:	Fri, 15 May 1998 11:10:38 GMT
Subject:	Strange mouse behaviour under Windows 95
Message-ID:	<C3292E6F40@fs2.mt.umist.ac.uk>

  I have just switched to Windows 95. I have run into these mouse effects:-
  In Windows applications, OK.
  If I run any DOS program from Shutdown, Restart in DOS mode, OK.

  But if I run a DOS program by calling it from Windows, or via the option
`MSDOS Prompt' from the menu that appears when I click `Start':-
  Word Perfect 5.1 for DOS seems to obey the mouse very sluggishly but always
or usually correctly.
  In Gnu C++ (v2) programs that I have:-

  CLEANUP.EXE does not use the mouse, and runs OK whatever I do with the mouse
while it is running.

  SPATRL.EXE uses the mouse, and runs with the screen in a graphics mode, and
runs OK. (It hooks interrupt 9.)

  AAEMACS.EXE uses the mouse, and runs with the screen in text mode 0x03. If
called by clicking it in a folder display window, it drops out the first time
I move the mouse even slightly. If called from a DOS prompt within Windows 95,
it does not drop out but it moves the mouse pointer completely different from
how I move the physical mouse.

  SPATRL.EXE and AAEMACS.EXE both hook the mouse with this function:-
/*-----*/
void Mouse::settrap(uns int mask,void (*func)(Regs*)) {
/* This is tricky in protected-mode. We must allocate a real-mode wrapper
   function which will be called by the mouse driver, and which in turn will
   switch to protected-mode and call our protected-mode handler function. */
if(!Jerry.nbuttons) return;
if(!func) {Jerry.handlerInstalled=0; /* remove handler */
    _go32_dpmi_free_real_mode_callback(&cb_info); R.dx=R.es=0;}
else { /* Allocate real-mode call-back. Find real-mode address of handler */
    cb_info.pm_offset=(uns long)func; Jerry.handlerInstalled=1;
    if(_go32_dpmi_allocate_real_mode_callback_retf(&cb_info,
      (__dpmi_regs*)&cb_regs)) return;
    R.dx=cb_info.rm_offset; R.es=cb_info.rm_segment;}
R.ax=12; R.cx=mask; Int(0x33);}

- Raw text -