RS232.exp

MODULE RS232;
IMPORT SYSTEM;
    CONST
        data = -56;
        stat = -52;

    PROCEDURE Send*(x : INTEGER);
    BEGIN
        REPEAT
        UNTIL SYSTEM.BIT(stat, 1);
        SYSTEM.PUT(data, x)
    END Send;

    PROCEDURE Rec*(VAR x : INTEGER);
    BEGIN
        REPEAT
        UNTIL SYSTEM.BIT(stat, 0);
        SYSTEM.GET(data, x)
    END Rec;

    PROCEDURE SendInt*(x : INTEGER);
        VAR
            i: INTEGER;
    BEGIN
        Send(1);
        i := 4;
        REPEAT
            i := i-1;
            Send(x);
            x := ROR(x, 8)
        UNTIL i = 0
    END SendInt;

    PROCEDURE SendHex*(x : INTEGER);
        VAR
            i: INTEGER;
    BEGIN
        Send(2);
        i := 4;
        REPEAT
            i := i-1;
            Send(x);
            x := ROR(x, 8)
        UNTIL i = 0
    END SendHex;

    PROCEDURE SendReal*(x : REAL);
        VAR
            i: INTEGER;
            u: INTEGER;
    BEGIN
        Send(3);
        u := ORD(x);
        i := 4;
        REPEAT
            i := i-1;
            Send(u);
            u := ROR(u, 8)
        UNTIL i = 0
    END SendReal;

    PROCEDURE SendStr*(x : ARRAY OF CHAR);
        VAR
            i: INTEGER;
            k: INTEGER;
    BEGIN
        Send(4);
        i := 0;
        REPEAT
            k := ORD(x[i]);
            Send(k);
            INC(i)
        UNTIL k = 0
    END SendStr;

    PROCEDURE RecInt*(VAR x : INTEGER);
        VAR
            i: INTEGER;
            x0: INTEGER;
            y: INTEGER;
    BEGIN
        i := 4;
        x0 := 0;
        REPEAT
            i := i-1;
            Rec(y);
            x0 := ROR(x0+y, 8)
        UNTIL i = 0;
        x := x0
    END RecInt;

    PROCEDURE RecReal*(VAR x : REAL);
        VAR
            i: INTEGER;
            x0: INTEGER;
            y: INTEGER;
    BEGIN
        i := 4;
        x0 := 0;
        REPEAT
            i := i-1;
            Rec(y);
            x0 := ROR(x0+y, 8)
        UNTIL i = 0;
        x := SYSTEM.VAL(REAL, x0)
    END RecReal;

    PROCEDURE RecStr*(VAR x : ARRAY OF CHAR);
        VAR
            i: INTEGER;
            k: INTEGER;
    BEGIN
        i := 0;
        REPEAT
            Rec(k);
            x[i] := CHR(k);
            INC(i)
        UNTIL k = 0
    END RecStr;

    PROCEDURE Line*;
    BEGIN
        Send(6)
    END Line;

    PROCEDURE End*;
    BEGIN
        Send(7)
    END End;

END RS232.