/******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
/&
	FIELD 0
	*4000  /CORRESPONDS TO BANK 2 IN THE LINC CPU.
	ISSP=6165
	ICON=6141
/
/
/
/
PDIS,	0
	CLA CLL
	TAD I PDIS /GET Y
	DCA Y
	ISZ PDIS
	TAD PK377 /COMPUTE  THE REAL X NEEDED FOR THE DISPLAY
	TAD I PDIS /GET X
	DCA X
	RDF /SET UP RETURN
	TAD PKCIF
	DCA PDISEX
	CDF 00
	TAD I PK4010 /SAVE MEMORY
	DCA PKSAVE
	ISZ PDIS /SET UP RETURN
/NOW GO GET SET TO LINC UP.
/CLEAR FLAGS
	TAD PK11
	ICON /CLEAR LINC HANGUPS
        CLA 
	TAD GOLINC
	ISSP
	CLA
	TAD PK10 /SELECT 
	ICON
	TAD PK2
MP,	 ICON /GO DISP
	CLA
	TAD PK11 /DESELECT THE LINK
	ICON
	CLA
	TAD PKSAVE /RESTORE MEMORY
	DCA I PK4010
PDISEX,	CIF 00
	JMP I PDIS /RETURN
/*****CONSTANTS******
GOLINC,	 LINC
PKCIF,	CIF 00
PKSAVE,	0
PK4010,	4010
PK377,	377
PK11,	11
PK10,	10
PK7,  	7
PK2,	2
X,	0
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.
/
/&
LINC,	0050	/SET 10 ----- LINC CODE
	X-4000
	1000	/LDA IN LINC CODE
	Y-4000
	150	/DIS 10....DISPLAY CHANNEL 0
	0000    /HLT IN LINC CODE
/RETURN TO PDP8 CPU
/CHANGE BACK MODE.
/.....................................................
$