Date: Fri, 9 Aug 1996 08:47:42 +1000 (EST)
From: John Joseph Newbigin <079519 AT bud DOT cc DOT swin DOT edu DOT au>
To: djgpp AT delorie DOT com
Subject: Re: Mouse: Allegro + Win95
In-Reply-To: <32021A9B.606A@eng.umd.edu>
Message-Id: <Pine.OSF.3.91.960809081640.15143A-100000-100000-100000@bud.cc.swin.edu.au>
Mime-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII

> The other problem is that the mouse moves slower in a Win95
> DOS session. This may be related to the problem above, or it
> could be something else. I see in the code that a correction is
> make for SVGA modes. Apparently, he multiplies all the mouse
> values by 8, to compensate for a problem with SVGA. He then
> divides by 8 whenever a mouse value is read. Its possible that
> Win95 does not need this compensation.

When you set the mouse limits, the mouse driver masks off tht last 3 bits 
(or shifts right or something) so if you set mouse limits from 0 to 1023 
for example, the mouse will only move from 0 to 1016.  A work around for 
this is then to multiply by 8 before sending the value to the mouse 
driver.  I haven't used Win95 do I don't know if it does the same thing 
but I probably does.  The solution then it to reduce the micky to pixel 
ratio or change the mouse speed



Newbs.
> 
> The problem is that under older versions of DOS, everything works
> fine. So, how do you get around this problem? Put in a 'detect'
> and set the 8 pixel compensation factor based on what the 'detect'
> returns. If this is the case, what should I be detecting? 
> 
> Any suggestions or thoughts?
> 
> -- 
> <docmani AT eng DOT umd DOT edu ------ http://www.glue.umd.edu/~docmani>
>