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  VAR
      DirectVideo : Boolean;    { state of direct video addressing }
 
  Unit:     Crt
 
  Context:  TextMode, Write, Writeln
 
  Description
 
    When DirectVideo is set to True, output to a file associated with
    the CRT is written directly into video memory.
 
    When DirectVideo is False, output is written through BIOS calls.
    Some multitasking systems experience conflicts when a program
    attempts to write directly to video display memory. Setting
    DirectVideo to False clears the problem, but causes slower
    output.
 
    Default setting is True. To ensure that output is continuously
    performed through BIOS calls, set DirectVideo to False after each
    TextMode call.