1

	  		/******PROGRAM PDIS.PAL,  1969******
	  		/PETER LEMKIN
	  		/NATIONAL INSTITUTES OF HEALTH
	  		/BETHESDA, MD. 20014
	  		/
	  		/
	  		/
	  		/INTRODUCTION:
	  		/------------
	  		/PDIS IS A SUBROUTINE FOR THE LINC8 COMPUTER USED TO
	  		/ACCESS THE LINC CPU'S POINT DISPLAY  HARDWARE FROM
	  		/THE PDP8 CPU. THIS GREATLY FACILITATES INCORPORATING THE
	  		/LINC DISPLAY IN PDP8 PROGRAMS.
	  		/
	  		/
	  		/
	  		/
	  		/HARDWARE REQUIRED:
	  		/------------------
	  		/LINC8 COMPUTER WITH AT LEAST 4K OF MEMORY.
	  		/PDIS WILL COMPILE WITH PAL.
	  		/
	  		/
	  		/
	  		/
	  		/
	  		/DESCRIPTION:
	  		/----------------
	  		/SUBROUTINE PDIS IS A POINT DISPLAY ROUTINE WHICH CAN BE
	  		/USED FOR DISPLAYING ARBITRARY SETS OF (X,Y) COORDINATES ON
	  		/THE LINC DISPLAY SCOPE. IT MAY BE CALLED FROM ANY FIELD. IT SHOULD
	  		/BE NOTED THAT THE DISPLAY ROUTINE MUST BE RESIDENT IN THE PART OF 
	  		/MEMORY WHICH CORRESPONDS TO THE CURRENT LINC CPU MEMORY BANK.
	  		/THE (X,Y)=(0,0) POSITION IS THE ENTER OF THE SCREEN. (+X,+Y)
	  		/IS TO THE RIGHT AND UP RESPECTIVELY.
	  		/CALLING SEQUENCE:
	  		/     JMS PDIS
	  		/     Y  /Y COORD -Y=-377, +Y=377
	  		/     X  /X COORD -X=-377, +X=377
	  		/     NORMAL RETURN
	  		/&
	  	0000		FIELD 0
	  	4000		*4000  /CORRESPONDS TO BANK 2 IN THE LINC CPU.
	  	6165		ISSP=6165
	  	6141		ICON=6141
	  		/
	  		/
	  		/
	  		/
	  4000	0000	PDIS,	0
	  4001	7300		CLA CLL
	  4002	1600		TAD I PDIS /GET Y
	  4003	3253		DCA Y
	  4004	2200		ISZ PDIS
	  4005	1245		TAD PK377 /COMPUTE  THE REAL X NEEDED FOR THE DISPLAY

						2

	  4006	1600		TAD I PDIS /GET X
	  4007	3252		DCA X
	  4010	6214		RDF /SET UP RETURN
	  4011	1242		TAD PKCIF
	  4012	3237		DCA PDISEX
	  4013	6201		CDF 00
	  4014	1644		TAD I PK4010 /SAVE MEMORY
	  4015	3243		DCA PKSAVE
	  4016	2200		ISZ PDIS /SET UP RETURN
	  		/NOW GO GET SET TO LINC UP.
	  		/CLEAR FLAGS
	  4017	1246		TAD PK11
	  4020	6141		ICON /CLEAR LINC HANGUPS
	  4021	7200	        CLA 
	  4022	1241		TAD GOLINC
	  4023	6165		ISSP
	  4024	7200		CLA
	  4025	1247		TAD PK10 /SELECT 
	  4026	6141		ICON
	  4027	1251		TAD PK2
	  4030	6141	MP,	 ICON /GO DISP
	  4031	7200		CLA
	  4032	1246		TAD PK11 /DESELECT THE LINK
	  4033	6141		ICON
	  4034	7200		CLA
	  4035	1243		TAD PKSAVE /RESTORE MEMORY
	  4036	3644		DCA I PK4010
	  4037	6202	PDISEX,	CIF 00
	  4040	5600		JMP I PDIS /RETURN
	  		/*****CONSTANTS******
	  4041	4054	GOLINC,	 LINC
	  4042	6202	PKCIF,	CIF 00
	  4043	0000	PKSAVE,	0
	  4044	4010	PK4010,	4010
	  4045	0377	PK377,	377
	  4046	0011	PK11,	11
	  4047	0010	PK10,	10
	  4050	0007	PK7,  	7
	  4051	0002	PK2,	2
	  4052	0000	X,	0
	  4053	0000	Y,	0
	  		/
	  		/
	  		/
	  		/
	  		/
	  		/SUBROUTINE LINC
	  		/IS A LINC CODE SUBROUTINE USED TO DISPLAY 1
	  		/POINT  AT X AND Y. IT IS CALLED AND STARTED BY PDIS.
	  		/
	  		/&
	  4054	0050	LINC,	0050	/SET 10 ----- LINC CODE
	  4055	0052		X-4000
	  4056	1000		1000	/LDA IN LINC CODE
	  4057	0053		Y-4000

						3

	  4060	0150		150	/DIS 10....DISPLAY CHANNEL 0
	  4061	0000		0000    /HLT IN LINC CODE
	  		/RETURN TO PDP8 CPU
	  		/CHANGE BACK MODE.
	  		/.....................................................
	  		$