/3 PDP-12 DISPLAY CODE FOR TECO

/ENTRY POINTS:

	.GLOBAL DSPLAY		/CALL TO REFRESH VR12

/EXTERNALS:

	.ZTERNAL P		/TEXT BUFFER POINTER
	.ZTERNAL NUMLNS		/NUMBER OF LINES (+ AND -) TO DISPLAY
	.ZTERNAL R		/LINKAGE TEMPORARY
	.ZTERNAL NAME		/4 WORDS OF TEMPORARIES

/PAGE 0 LITERALS:

	.ZTERNAL Z7		/7
	.ZTERNAL CAHT		/11
	.ZTERNAL Z177		/177
	.ZTERNAL Z4		/4
	.ZTERNAL ZM40		/-40

/EXTERNALS:

	.EXTERNAL CHRL1		/ADVANCES LINES
	.EXTERNAL PUSHJ		/RECURSUVE PUSH JUMP ROUTINE

	MTHREE=CLL STA RTL

YPOS=	NAME		/USE SOME FREE PAGE ZERO LOCATIONS
DR=	NAME+1		/FOR OUR TEMPORARIES
DQ=	NAME+2
DM=	NAME+3

	.XSECT TEC12X

DX,	0		/AUTO-INDEX REGISTER USED BY DISPLAY

	.ASECT	TECO12

	*4000

/DISPLAY ROUTINE FOR PDP-12 SCOPE

WASTE,	0		/** MUST BE AT MULTIPLE OF 2000
XPOS,	0		/PDP-12 BETA REGISTER 1
BETA2,	0		/PDP-12 BETA REGISTER 2

DSPLAY,	0		/TEXT DISPLAY ROUTINE FOR TECO
	MTHREE		/THIS ROUTINE DEPENDS ON THE FACT THAT THE
	TAD	DSPLAY	/HIGH ORDER BITS OF THE X-COORD ARE IGNORED
	DCA	DX	/BY THE VR12 HARDWARE
	TAD I	DX	/GET THE SKIP
	DCA	DLPTST	/PUT IT IN THE LOOP
	TAD	P
	DCA	DX
	TAD	NUMLNS
	STL CIA		/LOOK BACKWARD
	PUSHJ		/FOR BEGINNING OF DISPLAY AREA
		CHRL1
D360,	STA STL		/=7360
	TAD	P
	DCA	DM
	TAD	DX
	DCA	P	/RESTORE POSITION
	TAD	NUMLNS	/NOW SCAN FORWARD
	CLL IAC
	PUSHJ		/FOR THE END OF THE DISPLAY AREA
		CHRL1
	TAD	P
	CIA
	TAD	DM
	DCA	R	/*K* THIS NUMBER MUST GO IN R -
	TAD	DX	/THE W COMMAND NEEDS IT THERE
	DCA	P	/RESTORE ORIGINAL P
DSETUP,	TAD	P
	CIA
	TAD	DM
	DCA	DQ	/SAVE COUNT OF CHARS TO CURSOR POSITION
	TAD	DM
	DCA	DX
	TAD	R
	DCA	DR
	TAD	D360
	DCA	YPOS
DISCR,	TAD	DISLF
SETXPS,	DCA	XPOS	/SET X POSITION/COLUMN COUNTER
	JMP	DLPTST

	/DISPLAY LOOP

DGETCH,	CDF 10
	TAD I	DX
	CDF 0		/GET THE CHARACTER FROM FIELD 1
	AND	Z177	/AND OFF THE HIGH ORDER BITS
	TAD	(-33
	SNA		/CHANGE ALTMODES
	TAD	CAHT	/TO DOLLAR SIGNS
	TAD	(-5
	SMA SZA		/IF NOT A CONTROL CHARACTER
	JMP	DLOOP	/DISPLAY IT AND KEEP GOING
	SNA
	JMP	DBLANK	/DO BLANKS FAST
	TAD	(40-15
	SNA		/CR?
	JMP	DISCR	/YES - RESET X COORD
	STL
	TAD	Z4
	SNA		/TAB?
	JMP	DTABB
	SNL
	JMP	DISLF	/LINE FEED, VERTICAL TAB, OR FORM FEED
	TAD	(51	/ORDINARY CONTROL CHAR - RESTORE IT + 40
	DCA	WASTE	/SAVE CHAR
	JMS	DISCHR	/DISPLAY ^
	TAD	WASTE	/NOW DISPLAY ALTERED CHAR
DLOOP,	JMS	DISCHR

DLPTST,	HLT		/EITHER KSF OR TSF OR "ISZ R"
	SKP
	JMP I	DSPLAY	/EXIT IMMEDIATELY IF TEST SKIPS
	ISZ	DQ	/ARE WE AT THE CURRENT POINTER POSITION?
	JMP	TSTEDS	/NO
	TAD	(-5
	TAD	XPOS
	DCA	XPOS	/BACK UP X POSITION A HALF-CHARACTER
	TAD	DM20
	TAD	YPOS
	6141		/ENTER LINC MODE
DM20,	1760		/DSC I
	2000
	1760		/DISPLAY A ^
	2076
	0002		/PDP
	MTHREE		/AND MOVE X POSITION BACK TO WHERE IT WAS
	JMP	DBLANK+1
TSTEDS,	ISZ	DR	/ARE WE THROUGH?
	JMP	DGETCH	/NO
	JMP	DSETUP	/YES - START OVER

DTABB,	TAD	XPOS	/DISPLAY TAB
	CMA
	AND	Z7
	DCA	WASTE	/GET NUMBER OF COLUMNS TO GO (-1)
	TAD	WASTE
	CLL RTL
	RAL
	TAD	WASTE	/MULTIPLY BY 9
DBLANK,	TAD	CAHT	/BUMP ONE MORE COLUMN
	TAD	XPOS
	SZA		/OVERFLOW?
	JMP	SETXPS	/NO - SET XPOS AND CONTINUE
	JMP	LINOFL	/YES - GO TO THE NEXT LINE

/SUBROUTINE TO DISPLAY A CHARACTER

DISCHR,	DLPTST		/*K* DISCHR MUST CONTAIN "DLPTST" WHEN WE
	CLL RAL		/ARE EXAMINING CHARACTERS **
	TAD	(DTABLE-1
	DCA	BETA2	/STORE ADDRESS OF TABLE ENTRY FOR CHAR -1
	TAD	YPOS

	6141		/ENTER LINC MODE
	1762		/DSC I 2
	1762		/DSC I 2
	0002		/RE-ENTER PDP-8 MODE

	CLA
	ISZ	XPOS	/BUMP THE X COORDINATE/COLUMN COUNTER
	JMP I	DISCHR	/RETURN
LINOFL,	TAD	(7054	/INDENT ALL CONTINUATION LINES
	DCA	XPOS
DISLF,	RAR		/*K* RAR=7010  AC MAY HAVE A SMALL NUMBER
	TAD	YPOS	/IN IT HERE - THATS OK AS LONG AS ITS SMALL,
	TAD	ZM40	/SINCE ONLY THE HIGH 8 BITS OF YPOS COUNT.
	DCA	YPOS
	JMP I	DISCHR	/*K* THIS ALWAYS RETURNS TO DLPTST **
	PAGE

DTABLE,	2000;2076;	7500;0000;	7000;0070;	7714;1477
	5721;4671;	6661;4333;	5166;0526;	0000;0070
	3600;0041;	4100;0036;	2050;0050;	0404;0437
	0500;0006;	0404;0404;	0001;0000;	0601;4030
	4536;3651;	2101;0177;	4523;2151;	4122;2651
	2414;0477;	5172;0651;	1506;4225;	4443;6050
	5126;2651;	5122;3651;	2200;0000;	4601;0000
	1000;4224;	1212;1212;	2442;0010;	4020;2055
	4077;5751;	4477;7744;	5177;2651;	4136;2241
	4177;3641;	4577;4145;	4477;4044;	4136;2645
	1077;7710;	7741;0041;	4142;4076;	1077;4324
	0177;0301;	3077;7730;	3077;7706;	4177;7741
	4477;3044;	4276;0376;	4477;3146;	5121;4651
	4040;4077;	0177;7701;	0176;7402;	0677;7701
	1463;6314;	0770;7007;	4543;6151;	4177;0000
	3040;0106;	0000;7741;	2000;2076;	1604;0404