DEFINITION MODULE Terminal;

	PROCEDURE Read(VAR ch : CHAR);
	(* Read a character from the terminal and leave it in ch
	*)

	PROCEDURE BusyRead(VAR ch : CHAR);
	(* Read a character from the terminal and leave it in ch.
	   This is a non-blocking call. It returns 0C in ch if no
	   character was typed.
	*)

	PROCEDURE ReadAgain;
	(* Causes the last character read to be returned again upon the
	   next call of Read.
	*)

	PROCEDURE Write(ch : CHAR);
	(* Write character ch to the terminal.
	*)

	PROCEDURE WriteLn;
	(* Terminate line.
	*)

	PROCEDURE WriteString(s : ARRAY OF CHAR);
	(* Write string s to the terminal.
	*)

END Terminal.