*20
/OCTBIN 2
/FOR PDP-12
/D. J. NICHOLS
/UNIV. WISCONSIN
/
/CONVERTS OCTAL ASCII CODE TO BINARY
/
/THIS VERSION SEARCHES FOR THE QANDA
/  ANSWER FIELD DELIMITERS 74 AND 34
/CALL WITH IR 1 SET ANYWHERE BEFORE
/    THE FIRST DELIMITER
/CALLING SEQUENCE:
/  JMP OB2
/  ERROR RETURN
/  NORMAL RETURN
/INTERRUPTABLE
/USES INDEXES  1-2
/
OB2,	SET 2	/SAVE RETURN
	0
	LDH I 1 /GET CHAR
	SAE I 	/IS IT FIRST DELIMITER?
	74
	JMP .-3 /NO
	CLR	/CLEAR SUM
C9OB2,	STC D9OB2 /SAVE SUM
	LDH I 1 /LOAD NEXT CH.
	AZE I	/UNFILLED HALF WORD?
	JMP C9OB2+1 /YES: IGNORE IT
	SHD I	/SPACE?
	4000
	JMP C9OB2+1 /YES: IGNORE IT
	SHD I	/SECOND FIELD MARKER?
	7400
	JMP .+4
	SAE I
	34
	JMP E9OB2 /NO
	LDA I 2 /YES: INDEX RETURN
	LDA I	/LOAD RESULT
D9OB2,	0
	ROR 3	/REJUSTIFY
	JMP 2	/RETURN TO CALLING PGM
E9OB2,	SCR 3	/IS IT AN OCTAL DIGIT?
	SAE I
	6
	JMP 2	/ILLEGAL CHAR: ERROR RTN
	LDH 1	/OK: RELOAD
	BCL I	/MAKE BINARY
	7770
	ADD D9OB2 /ADD PREVIOUS SUM
	ROL 3
	JMP C9OB2
/END OCTBIN 2
/