FREQ
FREQ.12		SINE WAVE FREQUENCY COLLECTOR.
		MH-ICD,MN.		07/31/75.


FREQ.12 COLLECTS FREQUENCIES & INTENSITIES OF SERIES OF
50 MILLISECOND CONTINOUS TIME PERIODS. THE SOUND WAVE IS ENTERED
THROUGH ANALOG CHANNEL 17. EACH SAMPLE POINT OF THIS SOUND WAVE
CONSISTS OF 4 SAMPLES TAKEN CONTINOUSLY (AT A RAPID RATE), THEN
AVERAGED; TO HELP SMOTH OUT FREQUENCIES OTHER THAN THE FUNDAMENTAL
WAVE. THE 50 MS TIME SEGMENTS ARE PUT ON THE DATA TAPE (UNIT 1) FOR
LATER ANALYSIS BY OTHER PROGRAMS. EACH TIME SEGMENT CONTAINS AS DATA
1) THE NUMBER OF TIMES THE WAVE CROSES THE ZERO AXIS (FREQUENCY),
2) THE NUMBER OF SAMPLE POINTS READ (4 SAMPLES AVERAGED FOR ONE POINT),
3) A TWO WORD SUM OF THESE SAMPLES (THE INTENSITY).
EACH 256 WORD TAPE BLOCK CONTAINS 64 TIME SEGMENTS OF 3.2 SECONDS.
THE LINC-TAPE CONTAINS 1024 BLOCKS FOR A TOTAL COLLECTION TIME
OF ABOUT 50 MINUTES.


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	ABBRIVATIONS USED.

HLT	COMPUTER STOPS RUNNING. THIS IS TO ALLOW A NUMBER TO BE
	EITHER ENTERED THROUGH THE SWITCH REGISTERS, OR READ
	FROM THE AC.

AC	THE ACCUMULATOR LIGHTS. THIS NUMBER IS READ AS A SERIES
	OF 4 DIGIT OCTAL NUMBERS (IE. 7070). THIS NUMBER IS
	REPRESENTED BY ON=1/OFF=0 POSITIONS OF THE LIGHTS.
	0=000	4=100
	1=001	5=101
	2=010	6=110
	3=011	7=111

RS=	RIGHT SWITCH, ENTER A NUMBER IN THE

SSW0=	SENSE SWITCH 0 SET TO N, WHERE N IS EITHER 0 (OFF) OR 1 (ON).

CONT	PRESS THE SWITCH LABELED CONT ON THE SWITCH PANNEL.
FREQ

	FREQ SEQUENCE OF EVENTS.

LOAD TAPE "BINARY JAR" ON UNIT 0, LOAD 256 WORD/BLOCK DATA TAPE ON
UNIT 1. PREFORM STANDARD DEADSTART PROCEDURE. TYPE: "FREQ" TO THE
OS/12S MONITOR. THE FOLLOWING EVENTS WILL OCCUR:


1. HLT	AC=0707. SET SSW0=0, OFF. PUT STARTING BLOCK OF THE DATA
	COLLECTION TAPE IN THE RIGHT SWITCHES.
   RS=	FIRST BLOCK TO START STORING COLLECTION DATA.

  CONT	THIS DISPLAYS THE INCOMING SOUND WAVE FROM AN17 TO THE CRT
	WITH NO DATA COLLECTION. AT THIS TIME SET THE REPRODUCE LEVEL
	OF THE TAPE RECORDER TO AN ACCEPTABLE LEVEL.

2. SSW0=1	BEGIN SOUND DATA COLLECTION.

3. SSW0=0	STOP SOUND DATA COLLECTION.

4. HLT	AC=LAST BLOCK OF TAPE WRITTEN. WRITE DOWN THIS NUMBER ON
	PAPER. THE ANALYSIS PROGRAMS ASK FOR THIS NUMBER TO TELL
	WHERE THE END OF DATA IS ON THE DATA TAPE.

  CONT	RETURN TO STEP # 1.



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NOTE:	A DEADSTART IS NEEDED TO RETURN TO THE OS/12S MONITOR.

SEE:	FREQP.WU FOR FREQUENCY DATA PRINTOUT INFORMATION.