VGASCREEN

Purpose:  Controls the mode of a VGA-compatible display

Syntax:   VGASCREEN  = <<ENABLE|DISABLE>|<ON|OFF>>

Parameters:

ON      - activate the screen
OFF     - disactivate the screen
ENABLE  - enable writing to the video RAM
DISABLE - disable writing to the video RAM

Note:
     It worth to remember, that when OFF, the ENABLE and DISABLE commands
are ignored.

     The command allows to disactivate the screen or to organize video ROM
with VGA-compatible displays. Fully corresponds to the analogous BIOS calls.