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From: reino@cs.eur.nl (Reino de Boer)
Newsgroups: comp.lang.pascal
Subject: Re: TP Pageing in Textmode
Message-ID: <1989Dec11.085234.2846@cs.eur.nl>
Date: 11 Dec 89 08:52:34 GMT
References: <21679@adm.BRL.MIL>
Organization: Erasmus Universiteit Rotterdam, dept. CS (Informatica)
Lines: 45

kb36+@andrew.cmu.edu (Keith Douglas Beiter) writes:

>I am writing programs in TP5.0 for a friend that make up a help function
>[...text deleted...] he wants to have
>the programs I am writing on video page 3 in text mode ($bb00).  Since I
>am using the MEM command, I can easily send it to page 3.  The only
>trouble is, I cannot find anything in Turbo Pascal that deals with
>changing the visual/active page in text mode.  I can use the PAGE

Try the following:
{ uses dos }
var   old_page : byte;

function get_page : byte;
  var cpu : registers;
  begin
	cpu.ah := $0F; { Function 0FH: Get Current Video Mode }
	intr( $10, cpu ); { ROM BIOS Interrupt 10H: Video Services }
	get_page := cpu.bh
  end;

procedure set_page( pageno : byte );
  var cpu : registers;
  begin
	with cpu do begin
	  ah := $05H; { Function 05H: Select Active Page }
	  al := pageno
	end;
	intr( $10, cpu ) { ROM BIOS Interrupt 10H: Video Services }
  end;

begin
  old_page := get_page;
  set_page( 3 );
  { your code }
  set_page( old_page );
  { return to BASIC }
end.

Hope this helps -- Reino

-- 
Reino R. A. de Boer
Erasmus University Rotterdam ( Informatica )
e-mail: reino@cs.eur.nl