Category : Modula II Source Code
Archive   : M2MUSIC.ZIP
Filename : SPEAKER.DEF

DEFINITION MODULE Speaker;
(* Routines turn the speaker on at a given frequency,
to rurn it off again, and to delay processing for a set interval
Written for FST Modula-2 by Robin Roos and Pat Terry, November 1988 *)

CONST (* frequencies starting at Middle C *)
C = 262;
CSharp = 277;
DFlat = CSharp;
D = 294;
DSharp = 311;
Eflat = DSharp;
E = 330;
F = 349;
FSharp = 370;
GFlat = FSharp;
G = 392;
GSharp = 415;
AFlat = GSharp;
A = 440;
ASharp = 466;
BFlat = ASharp;
B = 494;

PROCEDURE Sound (FreqHz : CARDINAL);
(* Turn on speaker at frequency FreqHz *)

PROCEDURE NoSound;
(* Turn off speaker *)

PROCEDURE Delay (Time : CARDINAL);
(* Waste approximately Time milliseconds - based on counting loops *)

PROCEDURE ATDelay (Time : CARDINAL);
(* Waste Time milliseconds - AT specific *)

PROCEDURE Wait (Time : CARDINAL);
(* Wait approximately Time milliseconds - based on time of day *)

PROCEDURE PlayNote (Frequency, Time : CARDINAL);
(* Play a note at frequency for duration time (in milliseconds). *)

END Speaker.