CRT                 Display control unit
  Mode Constants      Screen mode constants
  Color Constants     Display color constants
  CheckBreak          CTRL-BREAK Activation/DeActivation
  CheckEOF            Enable/Disable EOF character
  CheckSnow           Enables/Disables snow checking
  DirectVideo         Enables/Disables direct video memory writes
  TextAttr            Sets the current Text/background colors
  WindMin             Stores minimum coordinates of current window
  WindMax             Stores maximum coordinates of current window