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From: jsd@swordfish.rice.edu (Shawn Joel Dube)
Newsgroups: comp.sys.ibm.pc.misc
Subject: Re: Help: How to remove snow checking?
Message-ID: <1991Mar15.233435.21050@rice.edu>
Date: 15 Mar 91 23:34:35 GMT
References: <1991Mar15.045316.18068@maverick.ksu.ksu.edu>
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Reply-To: jsd@swordfish.rice.edu (Shawn Joel Dube)
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In article <1991Mar15.045316.18068@maverick.ksu.ksu.edu>, slack@cis.ksu.edu (Jim Slack) writes:
|> Could someone please tell me how to remove snow checking from programs? 
|> 
|> I have a Tandy 1100FD laptop (which I *love*, by the way) which uses a CGA
|> screen.  There is absolutely no flicker, and thus no reason for a program
|> to do snow checking for this machine.  (Some of the very early IBM PCs
|> with CGA cards used to flicker when characters were placed in screen
|> memory directly.  Current computers don't usually have this problem.)

I believe that snow-checking is entirely up to the program so there
isn't a global variable.  Your method (modifying the code) is probably
the only method.  

Why snow-checking really slows down your machine deals with the 
way snow-checking works.  When snow-checking, a program only updates
the screen during a vertical retrace, (that is: whenever the computer
isn't drawing the screen).  I assume that with a laptop
screen that most of time, so there is very little time that a program
can modify screen memory which makes everything slow.

I hope that helped.

-- 
________________________________________________________________

  Shawn Joel Dube        "Never before have so many people known
  jsd@owlnet.rice.edu     so little about so much." -James Burke
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