100 /	LINC PING-PONG
 110 
 120 /	PING-PONG FOR THE CLASSIC LINC
 130 
 140 /	FROM THE LAP6 MANUSCRIPT ATTRIBUTED TO:
 150 /	MARK DIONNE MARCH MCMLXXIII
 160 
 170 /	TRANSLATED BY:	CHARLES LASNER	19-NOV-1990
 180 
 190 /	LAST EDIT:	19-NOV-1990	20:00
 200 
 210 /	MUST BE ASSEMBLED WITH P?S/8 PAL.
 220 
 230 /	MUST BE ASSEMBLED WITH '/8' AND '/J' SWITCHES SET.
 240 
 250 /	THIS  IS  A VISUAL PING-PONG PROGRAM WRITTEN ENTIRELY IN  LINC  CODE  FOR  THE
 260 /	CLASSIC LINC.  IT DEPENDS ON AN INTERRUPT CONDITION ARISING FROM SOME EXTERNAL
 270 /	SOURCE.  THE PLAYER PARAMETERS ARE UPDATED ON AN INTERRUPT-ONLY BASIS.
 280 
 290 /	HAND-MADE  CHANGES  ON  THE  ORIGINAL  MANUSCRIPT LISTING WILL BE INCORPORATED
 300 /	WHERE FEASIBLE.
 310 
 320 /	THIS LISTING IS FOR REFERENCE ONLY;  IT IS BEYOND  THE  SCOPE  OF THIS FILE TO
 330 /	ACTUALLY TRANSFER THE BINARY TO A CLASSIC LINC.  USING P?S/8,  IT  IS POSSIBLE
 340 /	TO  TRANSFER  THE  BINARY  FROM  A LINC-8 SYSTEM TO A LINCTAPE FOR  SUBSEQUENT
 350 /	LOADING ON  THE  CLASSIC  LINC.    TOWARDS  THAT  END, AND FOR POSSIBLE LINC-8
 360 /	EXECUTION, THE BINARY WILL BE LOADED USING LINC-8 CONVENTIONS.
 370 
 380 /	ALL SYMBOLS ARE REVERSED AS PER LAP6-DIAL CONVENTIONS.  THE SOURCE CONVENTIONS
 390 /	ARE  CONSISTENT  WITH  LAP6-DIAL, DIAL10, PAL-12, AND  P?S  PAL.    ERROR-FREE
 400 /	ASSEMBLY MAY ONLY BE POSSIBLE WITH P?S PAL.
 410 
 420 /	SYMBOL DEFINITIONS.
 430 
 440 	LMODE				/WE RUN IN LINC MODE
 450 
 460 	ENI=	0004			/ENABLE LINC INTERRUPTS
 470 
 480 /	MRI DEFINITIONS.
 490 
 500 	FIXMRI	JSR=	6000		/JUMP SUBROUTINE (WHICH RETURNS)
 510 	EJECT
 520 /	THE CODE STARTS HERE.
 530 
 540 	SEGMNT	1			/LOADS INTO 0000 ON CLASSIC LINC
 550 
 560 	*1				/EARLY LINC OPERATING SYSTEMS START IT HERE
 570 
 580 	ENI				/ENABLE INTERRUPTS
 590 
 600 /	CHECK WHAT STATE SENSE SWITCH 5 IS IN.  IF  IT IS CURRENTLY SET, THEN MAKE THE
 610 /	EXIT CONDITION THE CHANGE OF SENSE SWITCH 5 TO *OFF* ELSE LEAVE IT ALONE SO IT
 620 /	EXITS WITH SENSE SWITCH 5 *ON*.
 630 
 640 	SNS	5			/IS SENSE SWITCH 5 SET NOW?
 650 	JMP	START			/NO, JUST START IT
 660 	LDA I
 670 	SNS I	5			/GET REVERSING INSTRUCTION
 680 	STC	A6A			/STORE OVER EXIT CODE
 690 	JMP	START			/GO START IT UP
 700 
 710 	*20				/GET PAST ALPHA, BETA REGISTERS
 720 
 730 START,	JMP	A1A			/GOTO *REAL* START
 740 
 750 /	INTERRUPT LOCATION.
 760 
 770 	JMP	A1I			/HANDLE INTERRUPTS THERE
 780 
 790 /	DISPLAY LOOP
 800 
 810 A1A,	SET I	3
 820 A1B,	400
 830 	LDA I
 840 	30
 850 	SET I	2
 860 	-67				/THE NET
 870 A2L,	DIS	3
 880 	ADA I
 890 	57
 900 	XSK I	2
 910 	JMP	A2L
 920 	EJECT
 930 /	SCORES
 940 
 950 	SET	3
 960 	A1S
 970 	JSR	A5C
 980 	SET I	1
 990 	154				/**** WAS 10 ****
1000 	LDA I
1010 	300
1020 	DSC	2
1030 	DSC I	2
1040 	SET I	1
1050 	200				/**** WAS 34 ****
1060 	DSC	3
1070 	DSC I	3
1080 	SET	3
1090 	A2S
1100 	JSR	A5C
1110 	SET I	1
1120 	554				/**** WAS 724 ****
1130 	LDA I
1140 	300
1150 	DSC	2
1160 	DSC I	2
1170 	SET I	1
1180 	604				/**** WAS 750 ****
1190 	DSC	3
1200 	DSC I	3
1210 
1220 /	PADDLES
1230 
1240 	SET I	3
1250 	24
1260 	SAM	1			/LEFT
1270 	COM
1280 	ROL	2			/**** WAS ROL 3 ****
1290 	ADD	A1B
1300 	BCL I
1310 	7000
1320 	STC	A1P
1330 	SAM	7			/RIGHT
1340 	ROL	2			/WAS ROL 3 ****
1350 	ADD	A1B
1360 	BCL I
1370 	7000
1380 	STC	A2P
1390 	SET	2
1400 	A1P
1410 	JSR	A7P
1420 	SET	2
1430 	A2P
1440 	SET I	3
1450 	754
1460 	JSR	A7P
1470 	EJECT