.TITLE	.SIXPK
/
/  23 JUN 78 - PAUL HENDERSON
/
/  THIS ROUTINE CONSTRUCTS A .SIXBT FILE NAME AND EXTENSION AS
/  CHARACTERS ARE SUPPLIED, ONE CHARACTER PER CALL.  THE CONVENTION
/  USED IS THAT CHARACTERS ARE PACKED, THREE PER WORD, IN THE
/  FILE NAME AND EXTENSION.  ALL NON-SPACE CHARACTERS AFTER A
/  SPACE GO IN THE EXTENSION, EVEN IF THE FILE NAME IS NOT
/  COMPLETELY FILLED, OR IF THERE HAVE BEEN MORE THAN SIX
/  CHARACTERS.  ALL CHARACTERS AFTER THE NINTH (IF NO SPACE)
/  OR AFTER THE THIRD EXTENSION CHARACTER ARE IGNORED, AS ARE
/  ALL CHARACTERS INCLUDING AND AFTER A LINE TERMINATOR.
/     THE ROUTINE MUST BE INITIALIZED BY A CALL TO 'SIX.IN',
/  WHICH ALSO ZEROS THE 3-WORD FILE NAME BUFFER.
/
/  CALLING SEQUENCES:
/
/ 1) TO INITIALIZE -
/
/	LAC	(ADDRESS OF 3-WORD FILE NAME BUFFER
/	JMS*	SIX.IN
/	(RETURN)
/
/ 2) TO PACK CHARACTERS -
/
/	LAC	CHARACTER
/	JMS*	.SIXPK
/	(RETURN)
/
X10=10
SET=ISZ			/ SET A FLAG NON-ZERO
	.GLOBL	SIX.IN
/
SIX.IN	XX
	DAC	KPNT		/ KEEP ORIGINAL POINTER
	DAC	WPNT		/ WORKING POINTER GETS ALTERED
	DAC*	(X10
	DZM*	WPNT
	DZM*	X10		/ ZERO THE 3-WORD BLOCK
	DZM*	X10
	LAC	(FIRSTC
	DAC	SWING		/ SET UP THE BRANCH ADDRESSES
	LAC	(FNAME2
	DAC	SELECT
	DZM	TERMIN		/ CLEAR 'LINE TERMINATOR FOUND'
	JMP*	SIX.IN
/
KPNT;WPNT;TERMIN 1
	.EJECT
	.GLOBL	.SIXPK
/
.SIXPK	XX
	AND	(177		/ ENSURE WE HAVE ONLY 7 BITS
	SAD	(15		/ IF (CARRIAGE RETURN
	SKP
	SAD	(175		/ 	OR ALT MODE)
	JMP	CRALT		/    IGNORE ALL CHARACTERS UNTIL
				/    AFTER NEXT 'SIX.IN';
	SAD	(40		/ ELSEIF (SPACE)
	JMP	EXT		/    CHARACTERS GO IN EXTENSION
	AAC	-140
	SMA			/ IF (LOWER CASE)
	AAC	-40		/    CONVERT TO UPPER CASE
	AAC	140
	AND	(77		/ CHOP TO 6 BITS
	JMP*	SWING		/ THEN PROCESS CHARACTERS IN TURN
/\
SWING	OVRFLOW			/ IGNORE CHARACTERS UNLESS SET UP
	JMP*	.SIXPK
/
CRALT	SET	TERMIN		/ SET 'LINE TERMINATOR FOUND' FLAG
	JMP	OVRFLOW		/ THEN IGNORE CHARACTERS
/
NXT	JMS	SWING		/ ESTABLISH CORRECT BRANCH ADDRESS
/
FIRSTC	ALSS	14
	DAC*	WPNT		/ STORE FIRST CHARACTER
	JMS	SWING
/
	ALSS	6
	XOR*	WPNT		/ INCLUDE WITH 1ST CHAR
	DAC*	WPNT		/ AND STORE FIRST 2 CHARACTERS
	JMS	SWING
/
	XOR*	WPNT
	DAC*	WPNT		/ WORD NOW FULL.
	JMP*	SELECT		/ SELECT NEXT STAGE IN PROCESSING
/
	.EJECT
SELECT	OVRFLOW			/ IGNORE IF NOT SET UP
	JMP	NXT		/ SET UP WORD PACKER FOR
				/ ANOTHER 3 CHARACTERS
FNAME2	LAC	KPNT
	IAC			/ POINT TO SECOND WORD OF BLOCK
	DAC	WPNT
	JMS	SELECT
/
EXT	LAC	TERMIN		/ MUST CHECK BECAUSE A SPACE AFTER
	SZA			/ A LINE TERMINATOR COULD WREAK HAVOC
	JMP	OVRFLOW
	LAC	KPNT
	AAC	2
	DAC	WPNT		/ SELECT 3RD WORD (EXTENSION)
	JMS	SELECT
/
OVRFLOW	JMS	SWING		/ RETURN WITHOUT PROCESSING
	JMP	OVRFLOW		/ OVERFLOW CHARACTERS
	.END