C	PROGRAM HEADB
	COMMON IT0,IT,IS
	DIMENSION IT(255),IS(3)
SOPDEF CLSA	6135
C
C	SAMPLE EVERY 50MS
	CALL KWMEA(-1472,5,0)
C
	WRITE(3,91)
91	FORMAT(10X,'HEAD WITHDRAWAL EXPERIMENT'/
     +	5X,' -1.5 -1.0 -0.5 T=0  0.5  1.0  1.5'/)
C
C	I1 NUMBER OF RECORDED TRIALS
	I1=0
	J=0
C	WAIT FOR SS0 TO RESET
2	CALL DISP9(100,0,'HEADB')
	IF(LSENS(3))2,2,3
3	IF(ISENS(0))10,10,2
C
9	CALL RELAY(0,1)
C	LOOP WHILE BUTTON IS UP
10	IF(ISENS(0))11,11,20
11	CALL WAIT
	IF(LSENS(3))12,12,10
C	LOOP WHILE BUTTON IS DOWN
12	CALL WAIT
	IF(LSENS(3))12,12,13
C
C	FIND AND WRITE SAMPLES
13	CONTINUE
	CALL RELAY(0,0)
	IB=IT(IMOD((J-30)/256))
	I10=IT(IMOD((J-20)/256))-IB
	I5=IT(IMOD((J-10)/256))-IB
	I0=IT(J)-IB
	DO 15 I=1,30
	CALL WAIT
	J10=I/10
	IF(IREM(0))15,14,15
14	IS(J10)=IT(J)-IB
15	CONTINUE
	I1=I1+1
	WRITE(3,94)I1,IB,I10,I5,I0,IS
	GOTO 9
C
20	STOP
94	FORMAT(8I5)
C
C========================
C
C	SUBROUTINE WAIT
C
SENTRY	WAIT
SWAIT,	BLOCK 2
	J=IREM((J+1)/256)
C	UNTIL(CLSA<0)WAIT2
SWAIT2,	CLSA
SSMA CLA
SJMP WAIT2
	IT(J)=NALOG(8)
SRETRN	WAIT
C
C=====================
C
C	FUNCTION IMOD((J)),256
C
SENTRY IMOD
SIMOD,	BLOCK 2
SINC IMOD#
SINC IMOD#
	KMOD=IREM(0)
	IF(KMOD)51,52,52
51	KMOD=KMOD+256
52	CONTINUE
C	RETURN
STAD \KMOD
SRETRN IMOD
C
	END
$