DEFINITION MODULE ANSISYS;
(*
Facilities of the ANSI.SYS device driver
*)

(* ---------------------------------------------------------------------- *)
(* Cursor positioning *)

PROCEDURE GotoRowCol (row, column : CARDINAL);
(* Position to row, column.
   For CGA in 80x25 mode, if row or column is out of range, action is:
      row =  0: position to 1,column
      row > 25: ignore request!
   column =  0: position to row,1
   column > 80: position to row,80 *)

PROCEDURE GetRowCol (VAR row, column : CARDINAL);
(* Return current cursor position *)

PROCEDURE Up (n : CARDINAL);    (* Cursor up n rows *)
PROCEDURE Down (n : CARDINAL);  (* Cursor down n rows *)
PROCEDURE Right (n : CARDINAL); (* Cursor right n columns *)
PROCEDURE Left (n : CARDINAL);  (* Cursor left n columns *)
(* Preceding four requests are ignored if already at limit coordinate *)

PROCEDURE Save;                 (* Save the cursor position for Restore *)
PROCEDURE Restore;              (* Restore cursor to last Save'd position *)

(* ---------------------------------------------------------------------- *)
(* Mode control *)

TYPE
  Mode = (textMono40x25, textColour40x25, textMono80x25, textColour80x25,
          graphicsColour320x200x4, graphicsMono300x200, graphicsMono640x200,
          cursorWrap,
          um8, um9, um10, um11, um12, (* unused modes *)
          graphicsColour320x200, graphicsColour640x200x16,
          graphicsMono640x350, graphicsColour640x350x16,
          graphicsMono640x480, graphicsColour640x480x16,
          graphicsColour320x200x256);

PROCEDURE SetMode (mode : Mode);
(* Set video adapter to specified mode.
   ? Assume no effect if not a valid mode? *)

PROCEDURE ResetMode (mode : Mode);
(* Reset video adapter mode.
   Equivalent to SetMode except for cursorWrap (?).
   ? Assume no effect if not a valid mode? *)

(* ---------------------------------------------------------------------- *)
(* Attribute control *)

(* Attribute values - defined as an enumeration for convenient import.
   - italic and rapidBlink have no effect on CGA(?);
   - underscore is "available only on the Monochrome Graphics Adapter", but
     produces dark blue on black on CGA;
   - allOff is grey on black; reverse is black on grey;
   - concealed is black on black;
   - colours are dark unless bold (high intensity) is also selected - as well
     as brightness, bold also produces changes in apparent colour: red-brown
     to red, brown to yellow, grey to white *)
TYPE Attribute =
        (allOff, bold, faint, italic, underscore,
         blink, rapidBlink, reverse, concealed,
         ua9, (* unused attributes *)
         ua10, ua11, ua12, ua13, ua14, ua15, ua16, ua17, ua18, ua19,
         ua20, ua21, ua22, ua23, ua24, ua25, ua26, ua27, ua28, ua29,
         blackFG, redFG, greenFG, yellowFG, blueFG, magentaFG, cyanFG, whiteFG,
         u38, u39,
         blackBG, redBG, greenBG, yellowBG, blueBG, magentaBG, cyanBG, whiteBG);

PROCEDURE SetAttribute (attribute : Attribute);
(* Set given attribute.
   To come? Set AttibuteSet?
*)

(* ---------------------------------------------------------------------- *)
(* Erasing *)

PROCEDURE ClearScreen;
(* Clear the screen (to current background colour) and home the cursor *)

PROCEDURE EraseToEOL;
(* Erase to end of line *)

END ANSISYS.