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From:	Thomas8675309 AT yahoo DOT com (Tom)
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Improved dos bos for bash with scollable window ???
Date:	25 Nov 2003 13:56:05 -0800
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Hans-Bernhard Broeker wrote: 

> Your typical DOS program facing the need to e.g. control the cursor or
> display colours will typically do so by bypassing DOS completely and
> instead write directly into the videocard's memory, or at least resort
> to BIOS calls.  That kind of activity doesn't leave a trace that the
> XP console window or any other hypothetical xterm-alike could
> reasonably record and replay once you start scrolling around.  To even
> allow the program to hack the screen this way in spite of XP being a
> protected OS, the console window has to switch itself into a legacy
> compability mode, in which it acts as a virtual VGA card, with
> simulated frame buffers for the app to poke around in, and a simulated
> BIOS it can call.  This mode of operation is fundamentally
> incompatible with the concept of a scrollable terminal window.

Thanks for the additional explanation.  I get it now.

Best regards,

Tom

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