*20
/OCTBIN 1
/FOR PDP-12
/D. J. NICHOLS
/UNIV. WISCONSIN
/
/CONVERTS OCTAL ASCII CODE TO BINARY
/
/LOOKS AT FOUR 6-BIT CHARACTERSS
/CONVERTS IN THE RANGE 0000-7777
/CALLING SEQUENCE:
/  JMP OB1
/  ERROR RETURN
/  NORMAL RETURN
/ENTER WITH IR 1 SET 1/2 WORD AHEAD
/USES IR 1-3
/INTERRUPTABLE
/
OB1,	SET 3	/SAVE RETURN
	0
	SET I 2 /SETUP CH. CNTR
	-4	/ - (NO. CHS TO CONVERT)
	CLR
	STC D9OB1
B9OB1,	LDH I 1 /LOAD A CHARACTER
	SHD I	/SPACE?
	4000
	JMP C9OB1 /YES: IGNORE
	SCR 3	/IS IT AN OCTAL DIGIT?
	SAE I
	6
	JMP 3	/NON-OCTAL: ERROR RTN
	LDH 1	/OK: RELOAD
	BCL I	/MAKE BINARY
	7770
	ADD D9OB1 /PREVIOUS TOTAL
	ROL 3
	STC D9OB1
C9OB1,	XSK I 2 /ENOUGH CHS?
	JMP B9OB1 /NO
	LDA I 3 /YES: INDEX RTN
	LDA I	/LOAD RESULT
D9OB1,	0
	ROR 3	/REJUSTIFY
	JMP 3  /RETURN WITH BINARY IN AC
/END OCTBIN 1
/