PROGRAM main

IMPLICIT REAL*8(A-H)
IMPLICIT REAL*8(O-Z)
OPEN(1,STATUS='UNKNOWN',FILE='DATFIL');
W=2.
T=0.
S=0.
X=0.
XD=W
H=.01
DO WHILE(T <= 10.)
    S=S+H
    XDD=-W*W*X
    XD=XD+H*XDD
    X=X+H*XD
    T=T+H
    IF(S>=.09999)THEN
        S=0.
        XTHEORY=SIN(W*T)
        WRITE(9,*)T,X,XTHEORY
        WRITE(1,*)T,X,XTHEORY
    ENDIF
END DO

END PROGRAM main