C	PROGRAM OCT.FT
C	-----------------
C
C
C
	SUBROUTINE OCT(KOCT,IDEC,IOPR)
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C	PETER LEMKIN
C	NATIONAL INSTITUTE OF HEALTH
C	BETHESDA, MARYLAND.  20014
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C	MARCH 4, 1975
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C	PURPOSE
C	-------
C		OCT.FT CONVERTS DOUBLE PRECISION (MAGNITUDE)
C	INTEGER TO AND FROM 8 DIGIT OCTAL NUMBERS. KOCT IS
C	AN EXTERNALLY DIMENSION ARRAY KOCT(8) AND IDEC IS AN
C	EXTERNALLY DIMENSION ARRAY IDEC(2). IOPR DETERMINES THE
C	DIRECTION OF THE CONVERSION. THERE ARE NO ERROR 
C	CONDITIONS.
C	ARGUMENTS
C	----------
C	1. KOCT - ARRAY KOCT(8) OF 8 OCTAL DIGITS (PRINT WITH 8I1)
C	2. IDEC - ARRAY IDEC(2) OF UNSIGNED DECIMAL DIGITS
C	3. IOPR - CONVERSION DIRECTION WORD
C		0 OR -1      OCTAL TO DECIMAL
C		+1           DECIMAL TO OCTAL
C
C
C	******* PDP8E OPERATOR DEFINITIONS****
S	OPDEF TADI 1400 /INDIRECT TAD
S	OPDEF DCAI 3400 /INDIRECT DCA
C
C
C	[1] TEST CONVERSION DIRECTION IF >0 THEN DEC TO OCT 
C		ELSE OCT TO DEC.
	IF(IOPR)30,30,20
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C
C
C	[2] CONVERT IDEC[1:2] TO KOCT[1:8].
20	DO 200 M=1,2
	J=IDEC
S	INC \IDEC# /INCREMENT DUMMY POINTER
C
C
C		[2.1] BREAK THE WORD INTO 4 I1 WORDS.
C		COMPUTE THE INDEX INTO KOCT. TEST  IF [1:4] OR
C		[5:8] AND ADD OFFSETS TO COMPUTE THE INDEX BACKWARDS
C		FROM L.
		DO 200 L=1,4
S		CLA CMA
S		TAD \M /1=[1:4], 2=[5:8]
S		SZA CLA
S		TAD (4 /[5:8]
S		TAD (4 /[1:4] /TAKES CARE OF 0/1 OFFSET PROBLEM.
S		DCA 7 /TEMP
S		TAD \L
S		CIA
S		TAD 7 /COMPUTE OFFSET [(8*(M-1)+4*(2-M)) - L]
S		DCA 7
C
C
C		[2.2] GET OCTAL DIGIT
S		TAD \J /GET DECIMAL WORD
S		AND (0007 /GET OCTAL DIGIT
S		DCA OCTEMP /SAVE IT
S		TAD \J /ROTATE TO NEXT DIGIT (RIGHT)
S		CLL RAR
S		RTR
S		DCA \J
C
C
C		[2.3] SET UP THE DUMMY ADDRESS AND SAVE
S		TAD \KOCT /FIELD
S		DCA OCT1
S		TAD \KOCT# /POINTER
S		TAD 7 /OFFSET
S		DCA 7 /COMPLETED POINTER INTO KOCT[1:8]
S		TAD OCTEMP /GET COMPUTED DIGIT
S OCT1,		6201 /CDF OF KOCT.
S		DCAI 7
S		CPAGE 2
S		JMS 45 /CDFSKP
S		CLA
200		CONTINUE
		RETURN
S OCTEMP,	0 /TEMP LOC
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C	[3] CONVERT KOCT TO IDEC.
30	DO 302 M=1,2
C
C
C		[3.1] CONVERT EACH WORD TO DECIMAL AND THEN SAVE IT.
		DO 300 L=1,4
S		TAD \J
S		CLL RAL
S		RTL /ROTATE 3 LEFT (GARBAGE GETS LOST SO DON'T WORRY).
S		AND (7770 /MAKE SURE ONLY BITS 0:8.
S		DCA \J
C
C
C		[3.2] COMPUTE POINTER INTO KOCT[1:8]
S		CLA CMA
S		TAD \M
S		SZA CLA
S		TAD (4 /[5:8]
S		TAD \L
S		TAD (-1 /SINCE COUNT FROM 0 WANT (L-1)
S		TAD \KOCT# /POINTER TO KOCT[1:8]
S		DCA 7 /NOTE: POINTER TO KOCT[1] HAS OFFSET OF 0.
S		TAD \KOCT
S		DCA OCT2 /SAVE KOCT FIELD
C
C
C		[3.3] GET DIGIT AND PACK IT
S OCT2,	6201 /KOCT FIELD
S		TADI 7
S		CPAGE 2
S		JMS 45 /CDFSKP
S		NOP
S		AND (0007
S		TAD \J /COMPOSE THE DECIMAL WORD
S		DCA \J
300		CONTINUE
C
C
C		[3.4] SAVE WHEN FALL THROUGH
		IDEC=J
S		INC \IDEC# /INCREMENT DUMMY POINTER
302		CONTINUE
		RETURN
C
C
		END
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