PDP-10.its/src/spcwar/tvwar.20

	TITLE	SWR--SPACE WAR FOR TVS

A=1		;SUN BEING CONSIDERED
N=2		;SHIP BEING CONSIDERED
X=3		;POSITION
XT=4
Y=5
YT=6
T1=10		;TEMPORARIES
T2=11
TT=12
T3=13
T4=14
T5=15
D=16
SP=17		;STACK POINTER
IN=1		;INPUT CHANNEL
TYO=3		;OUTPUT CHANNEL
TVBFR=24000	;TOP OF TV
NDIREC==100
INCH==2		;INPUT CHNL FOR DISK
MAXSHP==3
MAXSUN==2
TORP==1
MAXOBJ==600

LOC 42
	JSR TSINT	;OLD-STYLE INTERRUPT HANDLER IN THIS LOCATION.
	
LOC 100
ST:	.OPEN	IN,OPNIN	;TTY INPUT, NO-WAIT MODE
		.VALUE
	.OPEN	TYO,OPNOUT	;TTY OUTPUT, 3 LINE ECHO AREA
		.VALUE
	.CALL	TVSCRN		;TV BUFFER MAP
		.VALUE
	.CALL	INSHIP		;OPEN THE DISK AND READ IN THE SHIP PATTERNS
		.VALUE	[ASCIZ/:NO SHIP FILES/]
	.IOT	INCH,PNTR
	.CLOSE	INCH,
	.CALL	INSINE		;OPEN THE DISK AND READ IN THE SINE WAVE
		.VALUE	[ASCIZ/:NO SINE WAVE FILE/]
	.IOT	INCH,PNTR1
	.CLOSE	INCH,
	.RTIME	TT,		;INITIALIZE THE RANDOM NUMBER
	MOVEM	TT,RANNUM
	MOVE	TT,TVBFR+20000	;GET TV ALU
	MOVEM	TT,TVALU

RESTRT:	MOVE	TT,TVALU
	MOVEM	TT,TVBFR+20000	;RESTORE TV ALU TO ORIGINAL
	HRRZI	TT,442.*18.-1	;CLEAR THE SCREEN
	SETZM	TVBFR(TT)
	SOJG	TT,.-1
	HRLZI	TT,22000	;TV SCREEN INTO XOR MODE
	XORM	TT,TVBFR+20000
NEWGAM:	MOVEI	SP,STACK
	SETZM	OBJLEN
	SKIPG	N,NSHIP
	JRST	NOSHPS
RANL:	SETZM	SWITCH-1(N)
	SKIPN	RANPOS
	JRST	NORAN
	PUSHJ	SP,RAND
	MOVE	X,TT
	PUSHJ	SP,RAND
	MOVE	Y,TT
	PUSHJ	SP,RAND
	MOVE	XT,TT
	PUSHJ	SP,RAND
	MOVE	YT,TT
	ANDI	X,77777
	ANDI	Y,77777
	ASH	XT,-34
	ASH	YT,-34
	PUSHJ	SP,BORDER
	PUSHJ	SP,RAND
	ANDI	TT,777
	JRST	RANSTR
NORAN:	MOVE	X,IPX-1(N)
	MOVE	Y,IPY-1(N)
	MOVE	XT,IVX-1(N)
	MOVE	YT,IVY-1(N)
	SETZ	TT,
RANSTR:	MOVEM	TT,DIRECT-1(N)
	MOVEM	X,PX-1(N)
	MOVEM	Y,PY-1(N)
	MOVEM	XT,VX-1(N)
	MOVEM	YT,VY-1(N)
	SOJG	N,RANL
NOSHPS:	SKIPN	A,NSUN		;PUT SUN(S) ON THE SCREEN
	JRST	PUTS
INITSN:	SKIPN	RANSUN
	JRST	NORANS
	PUSHJ	SP,RAND
	MOVE	X,TT
	PUSHJ	SP,RAND
	MOVE	Y,TT
	ANDI	X,77777
	ANDI	Y,77777
	MOVEI	XT,1000
	MOVEI	YT,1000
	PUSHJ	SP,BORDER
	JRST	RSNSTR
NORANS:	MOVE	X,IGRVX-1(A)
	MOVE	Y,IGRVY-1(A)
RSNSTR:	MOVEM	X,GRVX-1(A)
	MOVEM	Y,GRVY-1(A)
	PUSHJ	SP,PUTSUN
	SOJG	A,INITSN
PUTS:	SKIPG	N,NSHIP		;PUT SHIPS ON THE SCREEN
	JRST	SETINT
PUTLP:	PUSHJ	SP,PUTSHP
	SETOM	SHPSTS-1(N)
	SOJG	N,PUTLP
	SKIPG	N,NSHIP
	JRST	SETINT
	SKIPE	TALLY-1(N)
	JRST	REHANG
	SOJG	N,.-2
SETINT:	SKIPE	TEST		;SHOULD REALTIME BE SET UP?
	JRST	TSINT+2
	HRLZI	TT,710000	;SET THE REALTIME INTERRUPT
	HRRI	TT,TIME
	.SUSET	[.SMASK,,INTMSK]	;INTERRUPT FOR REALTIME
	.REALT	TT,
		.VALUE [ASCIZ/:.REALT FAILED TO SKIP.VP /]
	JRST	RHJFCL
REHANG:	SKIPE	TEST		;IN REALTIME MODE?
	JRST	TSTSLP
	.DISMISS TSINT+1
		.VALUE [ASCIZ/:GACK!  THESE OLD TIME INTERRUPTS ARE WIERD!/]
RHJFCL:	JFCL
	.HANG

INTMSK:	%PIRLT

TSINT:	0			;PC, ETC. GO HERE
	0
	PUSHJ	SP,CRASH	;CHECK FOR COLLISIONS
	PUSHJ	SP,SMACK
	PUSHJ	SP,HIT
	PUSHJ	SP,DFND
	SOS	SHOTTM
	SOS	SHOTTM+1
	PUSHJ	SP,SCORE
	MOVE	N,NSHIP
LOOP:	SKIPGE	SHPSTS-1(N)
	JRST	LOPOK
	SKIPG	SHPSTS-1(N)
	JRST	LOPEND
	SOS	SHPSTS-1(N)
	JRST	LOPDED
LOPOK:	PUSHJ	SP,REPOS	;DO ANOTHER TIME INCREMENT
	PUSHJ	SP,CLRSHP
	PUSHJ	SP,VELPOS
	PUSHJ	SP,PUTSHP
LOPEND:	SOJG	N,LOOP
	PUSHJ	SP,DISOBL
	SKIPE	TEST		;IN REALTIME MODE?
	JRST	TSTSLP
	.DISMISS TSINT+1
		.VALUE [ASCIZ/:GACK!  THESE OLD TIME INTERRUPTS ARE WIERD!/]
TSTSLP:	MOVE	TT,TIME		;NOT IN REALTIME, SO JUST SLEEP ON IT
	.SLEEP	TT,
	JRST	TSINT+2

LOPDED:	PUSHJ	SP,REPOS
	PUSHJ	SP,VELPOS
	MOVE	TT,SHPSTS-1(N)
	TRNN	TT,1
	JRST	PUTDWN
	JRST	PUTUP
PUTDWN:	PUSHJ	SP,CLRSHP
	JRST	LOPEND
PUTUP:	PUSHJ	SP,PUTSHP
	JRST	LOPEND

SCORE:	SKIPG	N,NSHIP
	JRST	SCRL
SCRLP:	MOVE	TT,SHPSTS-1(N)
	CAIE	TT,1
	JRST	SCRNXT
	SKIPG	TT,NSHIP
	JRST	SCRNXT
	SKIPGE	SHPSTS-1(TT)
	AOS	TALLY-1(TT)
	SOJG	TT,.-2
SCRNXT:	SOJG	N,SCRLP
SCRL:	SKIPG	N,NSHIP
	JRST	SCRXIT
	SETO	TT,
SCRXL:	SKIPE	SHPSTS-1(N)
	AOJG	TT,SCROK
	SOJG	N,SCRXL
SCRXIT:	POP	SP,
	.IOT	TYO,[15]
	.IOT	TYO,[12]
	.IOT	TYO,[12]
	SKIPG	N,NSHIP
	JRST	SCRXIT
SCRPL:	.IOT	TYO,[40]
	.IOT	TYO,[40]
	MOVE	T1,TALLY-1(N)
	PUSHJ	SP,PRNUM
	SOJG	N,SCRPL
	MOVE	TT,SCRTIM
	.SLEEP	TT,
	MOVE	TT,TVALU
	MOVEM	TT,TVBFR+20000	;RESTORE TV ALU TO ORIGINAL
	HRRZI	TT,407.*18.-1	;CLEAR THE SCREEN
	SETZM	TVBFR(TT)
	SOJG	TT,.-1
	HRLZI	TT,22000	;TV SCREEN INTO XOR MODE
	XORM	TT,TVBFR+20000
	JRST	NEWGAM
SCROK:	POPJ	SP,


DISOBL:	SETZ	T2,		;DISPLAY THE TORPS
	SKIPN	OBJLEN
	POPJ	SP,
	MOVE	X,OBJCL(T2)
	CAIE	X,TORP
	JRST	NOTRP
	SOSL	X,OBJCL+5(T2)
	JRST	NOTRP
	MOVE	X,OBJCL+1(T2)
	MOVE	Y,OBJCL+2(T2)
	PUSHJ	SP,DISPLY
	PUSHJ	SP,DELTRP
	JRST	DISOLP
NOTRP:	ADDI	X,1
	CAML	X,TRPLIF
	JRST	DIS1
	MOVE	X,OBJCL+1(T2)
	MOVE	Y,OBJCL+2(T2)
	PUSHJ	SP,DISPLY
DIS1:	MOVE	X,OBJCL+1(T2)	;ADD TORP VELOCITY TO POSITION
	MOVE	Y,OBJCL+2(T2)
	MOVE	XT,OBJCL+3(T2)
	MOVE	YT,OBJCL+4(T2)
	ADD	X,XT
	ADD	Y,YT
	PUSHJ	SP,BORDER	;CHECK FOR WRAP OR BOUNCE
	MOVEM	X,OBJCL+1(T2)	;MAKE THE NEW POSITION AND VELOCITY PERMANENT
	MOVEM	Y,OBJCL+2(T2)
	MOVEM	XT,OBJCL+3(T2)
	MOVEM	YT,OBJCL+4(T2)
	PUSHJ	SP,DISPLY
	ADDI	T2,6
DISOLP:	CAMGE	T2,OBJLEN	;FINISHED WITH THE TORPS YET?
	JRST	DISOBL+1
	POPJ	SP,

DELTRP:	HRLI	TT,OBJCL+6(T2)	;DELETE TORP(T2) FROM THE OBJCL LIST
	HRRI	TT,OBJCL(T2)
	BLT	TT,MAXOBJ+OBJCL-7
	MOVE	TT,OBJLEN
	SUBI	TT,6
	MOVEM	TT,OBJLEN
	POPJ	SP,

DISPLY:	LSH	X,-6		;PUT A 2X2 POINT AT X,Y (USUALLY A TORP)
	LSH	Y,-6
	IMULI	Y,18.
	IDIVI	X,32.
	ADD	Y,X
	MOVNS	XT
	HRLZI	T4,600000
	LSH	T4,(XT)
	TRZN	T4,17
	JRST	.+4
	HRLZI	T5,400000
	MOVEM	T5,TVBFR+1(Y)
	MOVEM	T5,TVBFR+19.(Y)
	MOVEM	T4,TVBFR(Y)
	MOVEM	T4,TVBFR+18.(Y)
	POPJ	SP,

MKTRP1:	SETZ	T1,		;GENERATE A TORPEDO AND ENTER IT ON THE OBJCL LIST
	SKIPLE	SHOTTM
	POPJ	SP,
	MOVE	TT,RLDTIM
	MOVEM	TT,SHOTTM
	JRST	MKALL
MKTRP2:	HRRZI	T1,1
	SKIPLE	SHOTTM+1
	POPJ	SP,
	MOVE	TT,RLDTIM
	MOVEM	TT,SHOTTM+1
MKALL:	SKIPL	SHPSTS(T1)
	POPJ	SP,
	MOVE	TT,OBJLEN
	CAIL	TT,MAXOBJ
	POPJ	SP,
	MOVE	TT,DIRECT(T1)
	PUSHJ	SP,DXDY
	MOVNS	Y
	MOVE	XT,X
	MOVE	YT,Y
	IMUL	XT,TRPVEL
	IMUL	YT,TRPVEL
	IMUL	X,XPLODR
	IMUL	Y,XPLODR
	ASH	X,-7
	ASH	Y,-7
	ASH	XT,-3
	ASH	YT,-3
	SUB	X,XT
	SUB	Y,YT
	ADD	X,PX(T1)
	ADD	Y,PY(T1)
	ADD	XT,VX(T1)
	ADD	YT,VY(T1)
	MOVEI	T5,TORP
	MOVE	T2,OBJLEN
	MOVEM	T5,OBJCL(T2)
	MOVEM	X,OBJCL+1(T2)
	MOVEM	Y,OBJCL+2(T2)
	MOVEM	XT,OBJCL+3(T2)
	MOVEM	YT,OBJCL+4(T2)
	MOVE	YT,TRPLIF
	MOVEM	YT,OBJCL+5(T2)
	ADDI	T2,6
	MOVEM	T2,OBJLEN
	POPJ	SP,

CRASH:	SKIPG	N,NSHIP		;CRASH=SHIP-TO-SUN COLLISION
	POPJ	SP,
CRSHP:	SKIPL	SHPSTS-1(N)
	JRST	NOSUN
	SKIPG	A,NSUN
	POPJ	SP,
CRSHPL:	MOVE	X,PX-1(N)
	SUB	X,GRVX-1(A)
	MOVMS	X
	CAML	X,SUNRAD
	JRST	CRNXT
	MOVE	Y,PY-1(N)
	SUB	Y,GRVY-1(A)
	MOVMS	Y
	CAML	Y,SUNRAD
	JRST	CRNXT
	MOVE	XT,XPLDTM
	ADDM	XT,SHPSTS-1(N)
	SKIPA
CRNXT:	SOJG	A,CRSHPL
NOSUN:	SOJG	N,CRSHP
	POPJ	SP,

SMACK:	SKIPG	N,NSHIP		;SMACK=SHIP-TO-SHIP COLLISION
	POPJ	SP,
SMK:	SKIPN	SHPSTS-1(N)	;IF THE SHIP FLIES OR DIES, ITS VALID
	JRST	SMKNXT
	MOVE	A,N
	SOJLE	A,SMACK+1	;IF THERE AREN'T TWO SHIPS, THEY CAN'T HIT
SMKRPT:	SKIPN	SHPSTS-1(A)
	JRST	SMKLP
	MOVE	XT,PX-1(N)	;SEE IF THEY REALLY HIT
	SUB	XT,PX-1(A)
	MOVMS	XT
	CAML	XT,XPLODR
	JRST	SMKLP
	MOVE	YT,PY-1(N)
	SUB	YT,PY-1(A)
	MOVMS	YT
	CAML	YT,XPLODR
	JRST	SMKLP
	MOVE	XT,VX-1(N)	;AVERAGE THE TWO VELOCITIES
	MOVE	X,VX-1(A)
	ASH	XT,-1
	ASH	X,-1
	SKIPGE	SHPSTS-1(A)
	ADDM	XT,VX-1(A)
	SKIPGE	SHPSTS-1(N)
	ADDM	X,VX-1(N)
	MOVE	YT,VY-1(N)
	MOVE	Y,VY-1(A)
	ASH	YT,-1
	ASH	Y,-1
	SKIPGE	SHPSTS-1(A)
	ADDM	YT,VY-1(A)
	SKIPGE	SHPSTS-1(N)
	ADDM	Y,VY-1(N)
	SKIPGE	SHPSTS-1(N)	;MAKE THEM DISAPPEAR
	PUSHJ	SP,CLRSHP
	EXCH	A,N
	SKIPGE	SHPSTS-1(N)
	PUSHJ	SP,CLRSHP
	EXCH	A,N
	MOVE	XT,XPLDTM	;THEY HIT, SO MAKE THEM EXPLODE
	SKIPGE	SHPSTS-1(N)	;BUT ONLY IF THEY AREN'T ALREADY
	MOVEM	XT,SHPSTS-1(N)
	SKIPGE	SHPSTS-1(A)
	MOVEM	XT,SHPSTS-1(A)
SMKLP:	SOJG	A,SMKRPT
SMKNXT:	SOJG	N,SMK
	POPJ	SP,

HIT:	SETZ	T2,		;HIT=TORP-TO-SHIP COLLISION
	CAML	T2,OBJLEN
	POPJ	SP,
	SKIPG	N,NSHIP
	POPJ	SP,
HITSHL:	SKIPN	SHPSTS-1(N)
	JRST	HITNXT
	MOVE	X,PX-1(N)
	SUB	X,OBJCL+1(T2)
	MOVMS	X
	CAML	X,XPLODR
	JRST	HITNXT
	MOVE	Y,PY-1(N)
	SUB	Y,OBJCL+2(T2)
	MOVMS	Y
	CAML	Y,XPLODR
	JRST	HITNXT
	MOVE	XT,XPLDTM
	ADDM	XT,SHPSTS-1(N)
	MOVE	X,OBJCL+3(T2)
	ASH	X,-2
	ADD	X,VX-1(N)
	MOVE	Y,OBJCL+4(T2)
	ASH	Y,-2
	ADD	Y,VY-1(N)
	MOVEM	X,VX-1(N)
	MOVEM	Y,VY-1(N)
	MOVE	X,OBJCL+1(T2)
	MOVE	Y,OBJCL+2(T2)
	PUSHJ	SP,DISPLY
	PUSHJ	SP,DELTRP
	SKIPA
HITNXT:	SOJG	N,HITSHL
	ADDI	T2,6
	JRST	HIT+1

DFND:	SETZ	T1,		;DFND=TORP-TO-TORP COLLISION
	MOVE	T2,T1
DFNDL:	ADDI	T2,6
	CAML	T2,OBJLEN
	JRST	DFNDXT
	MOVE	X,OBJCL+1(T1)
	SUB	X,OBJCL+1(T2)
	MOVMS	X
	CAML	X,XPLODR
	JRST	DFNDL
	MOVE	Y,OBJCL+2(T1)
	SUB	Y,OBJCL+2(T2)
	MOVMS	Y
	CAML	Y,XPLODR
	JRST	DFNDL
	MOVE	X,OBJCL+3(T1)
	ADD	X,OBJCL+3(T2)
	ASH	X,-1
	MOVEM	X,OBJCL+3(T1)
	MOVE	Y,OBJCL+4(T1)
	ADD	Y,OBJCL+4(T2)
	ASH	Y,-1
	MOVEM	Y,OBJCL+4(T1)
	SETZM	OBJCL+5(T1)
	MOVE	X,OBJCL+1(T2)
	MOVE	Y,OBJCL+2(T2)
	PUSHJ	SP,DISPLY
	PUSHJ	SP,DELTRP
	JRST	DFNDL
DFNDXT:	ADDI	T1,6
	CAML	T1,OBJLEN
	POPJ	SP,
	JRST	DFNDL-1

REPOS:	SKIPN	A,NSUN		;CALCULATE ACCELERATION ON SHIP#N
	POPJ	SP,		;NO SUNS TO CHANGE VELOCITY
RPSLP:	MOVE	X,PX-1(N)
	MOVE	Y,PY-1(N)
	SUB	X,GRVX-1(A)
	SUB	Y,GRVY-1(A)
	MOVE	XT,X
	MOVE	YT,Y
	IMUL	XT,XT
	IMUL	YT,YT
	MOVE	T1,XT
	ADD	T1,YT
	MOVE	D,T1
	PUSHJ	SP,ISQRT
	MOVE	TT,GRAV
	IMUL	TT,GRVK-1(A)
	IDIV	T1,TT
	HRLZ	X,X
	HRLZ	Y,Y
	IDIV	X,T1
	IDIV	Y,T1
	LSH	D,-2
	IDIV	X,D
	IDIV	Y,D
	SUB	X,VX-1(N)
	SUB	Y,VY-1(N)
	MOVNM	X,VX-1(N)
	MOVNM	Y,VY-1(N)
	MOVMS	X
	MOVMS	Y
	CAML	X,MAXVEL
	SETZM	VX-1(N)
	CAML	Y,MAXVEL
	SETZM	VY-1(N)
	SOJG	A,RPSLP
	POPJ	SP,

VELPOS:	.IOT	IN,TT		;INPUT ANY COMMANDS
	CAIN	TT,":
	PUSHJ	SP,MKTRP1
	CAIN	TT," 
	PUSHJ	SP,MKTRP2
	CAIN	TT,"[
	MOVEM	TT,SWITCH
	CAIN	TT,"]
	MOVEM	TT,SWITCH
	CAIN	TT,"\
	MOVEM	TT,SWITCH
	CAIN	TT,"/
	MOVEM	TT,SWITCH
	CAIN	TT,"Z
	MOVEM	TT,SWITCH+1
	CAIN	TT,"X
	MOVEM	TT,SWITCH+1
	CAIN	TT,"C
	MOVEM	TT,SWITCH+1
	CAIN	TT,"V
	MOVEM	TT,SWITCH+1
	MOVE	TT,SWITCH-1(N)
	MOVE	T1,DIRECT-1(N)
	CAIE	N,1		;PERFORM THE LAST COMMAND OF SHIP #N
	JRST	VLPS2
	CAIN	TT,"[
	ADD	T1,SHPSPN
	CAIN	TT,"]
	SUB	T1,SHPSPN
	CAIN	TT,"\
	PUSHJ	SP,SPEED
	JRST	VLPALL
VLPS2:	CAIN	TT,"Z
	ADD	T1,SHPSPN
	CAIN	TT,"X
	SUB	T1,SHPSPN
	CAIN	TT,"C
	PUSHJ	SP,SPEED
VLPALL:	ANDI	T1,777		;DIRECTION IS A 9 BIT NUMBER
	MOVEM	T1,DIRECT-1(N)
	MOVE	X,PX-1(N)	;REPOSITION AND CHECK FOR WRAP OR BOUNCE
	MOVE	Y,PY-1(N)
	ADD	X,VX-1(N)
	ADD	Y,VY-1(N)
	MOVE	XT,VX-1(N)
	MOVE	YT,VY-1(N)
	PUSHJ	SP,BORDER
STASH:	MOVEM	X,PX-1(N)	;MAKE IT PERMANENT
	MOVEM	Y,PY-1(N)
	MOVEM	XT,VX-1(N)
	MOVEM	YT,VY-1(N)
	POPJ	SP,

BORDER:
CHKXL:	CAML	X,LEFTF		;CHECK FOR WRAP OR BOUNCE
	JRST	CHKXR
	SKIPE	BOUNCE
	JRST	.+3
	ADD	X,WIDE
	JRST	CHKXL
	MOVMS	XT
	JUMPG	XT,.+2
	ADDI	XT,1
	ADD	X,XT
CHKXLP:	ADD	X,XT
	CAMGE	X,LEFTF
	JRST	CHKXLP
CHKXR:	CAMG	X,RITEF
	JRST	CHKYT
	SKIPE	BOUNCE
	JRST	.+3
	SUB	X,WIDE
	JRST	CHKXR
	MOVMS	XT
	JUMPG	XT,.+2
	ADDI	XT,1
	MOVNS	XT
	ADD	X,XT
CHKXRP:	ADD	X,XT
	CAMLE	X,RITEF
	JRST	CHKXRP
CHKYT:	CAML	Y,TOPF
	JRST	CHKYB
	SKIPE	BOUNCE
	JRST	.+3
	ADD	Y,HIGH
	JRST	CHKYT
	MOVMS	YT
	JUMPG	YT,.+2
	ADDI	YT,1
	ADD	Y,YT
CHKYTP:	ADD	Y,YT
	CAMGE	Y,TOPF
	JRST	CHKYTP
CHKYB:	CAMG	Y,BTMF
	POPJ	SP,
	SKIPE	BOUNCE
	JRST	.+3
	SUB	Y,HIGH
	JRST	CHKYB
	MOVMS	YT
	JUMPG	YT,.+2
	ADDI	YT,1
	MOVNS	YT
	ADD	Y,YT
CHKYBP:	ADD	Y,YT
	CAMLE	Y,BTMF
	JRST	CHKYBP
	POPJ	SP,

SPEED:	MOVE	TT,DIRECT-1(N)	;CALCULATE SHIP'S ACCELERATION DUE TO ENGINES
	PUSHJ	SP,DXDY
	IMUL	X,SHPACC
	IMUL	Y,SHPACC
	LSH	X,-12
	LSH	Y,-12
	MOVNS	Y
	HRRES	X
	HRRES	Y
	ADDM	X,VX-1(N)
	ADDM	Y,VY-1(N)
	POPJ	SP,

ISQRT:	HRRZI	T4,30			;INTEGER SQUARE-ROOT SUBR., T1 TO T1
	MOVE	T2,T1
	MOVE	T3,T1
	MOVE	T1,10000
ISQRTL:	IDIV	T2,T1
	ADD	T1,T2
	LSH	T1,-1
	MOVE	T2,T3
	SOJG	T4,ISQRTL
	POPJ	SP,

DXDY:	MOVE	T5,TT		;SINE AND COSINE LOOKUP
	ANDI	T5,777		;TT CONTAINS ANGLE, 9 BIT = FULL CIRCLE
	MOVE	Y,SIN(T5)
	ADDI	T5,200
	ANDI	T5,777
	MOVE	X,SIN(T5)
	POPJ	SP,

RANMSK:	401020003045
RANNUM:	0
RAND:	MOVE	TT,RANNUM	;GENERATE RANDOM #,USING FEEDBACK S-R
	AND	TT,RANMSK
	SETZ	T1,
	JUMPGE	TT,.+2
	SETCA	T1,
	LSH	TT,1
	JUMPN	TT,.-3
	ANDI	T1,1
	MOVE	TT,RANNUM
	LSH	TT,1
	IOR	TT,T1
	MOVEM	TT,RANNUM
	POPJ	SP,

PRNUM:	MOVEI	T3,4
PRLP:	IDIVI	T1,10.
	PUSH	SP,T2
	SOJG	T3,PRLP
	MOVEI	T3,4
PRL:	POP	SP,T1
	.IOT	TYO,[40]
	JUMPN	T1,PRN
	SOJG	T3,PRL
PRN:	ADDI	T1,60
	.IOT	TYO,T1
	POP	SP,T1
	SOJG	T3,PRN
	JRST	(T1)

PUTSUN:	LSH	X,-6		;DISPLAY A SUN AT X,Y
	LSH	Y,-6
	IMULI	Y,18.
	ADDI	X,16.
	IDIVI	X,32.
	ADD	Y,X
	MOVNS	XT
	MOVEI	T1,31.
	ADDI	Y,16.*18.
PUTLOP:	MOVE	T3,SUN(T1)
	SETZ	T4,
	LSHC	T3,(XT)
	LSH	T3,4
	MOVEM	T3,TVBFR-1(Y)
	MOVEM	T4,TVBFR(Y)
	SUBI	Y,18.
	SOJGE	T1,PUTLOP
	POPJ	SP,

CLRSHP:	MOVE	T3,N		;DISPLAY SHIP IN CLRS BUFFER (ERASES TOO)
	SUBI	T3,1
	IMULI	T3,70.
	MOVE	T1,CLRS(T3)
	SUBI	T1,1
	MOVEI	T4,32.
CLRLP:	SKIPE	T2,CLRS+1(T3)
	MOVEM	T2,TVBFR(T1)
	SKIPE	T2,CLRS+2(T3)
	MOVEM	T2,TVBFR+1(T1)
	ADDI	T3,2
	ADDI	T1,18.
	SOJG	T4,CLRLP
	POPJ	SP,

PUTSHP:	MOVE	T3,N		;REGENERATE A CLRS FIELD
	SUBI	T3,1
	MOVE	T4,T3
	IMULI	T3,70.
	IMULI	T4,NDIREC*10
	ADD	T4,DIRECT-1(N)
	LSH	T4,-3
	IMULI	T4,32.
	SETZM	CLRS+1(T3)
	HRRZI	TT,CLRS+2(T3)
	HRLI	TT,CLRS+1(T3)
	BLT	TT,CLRS+64.(T3)
	MOVE	T1,PX-1(N)
	LSH	T1,-6
	ADDI	T1,16.
	IDIVI	T1,32.
	MOVNS	T2
	MOVE	TT,PY-1(N)
	LSH	TT,-6
	SUBI	TT,16.
	IMULI	TT,18.
	ADD	T1,TT
	MOVEM	T1,CLRS(T3)
	MOVEI	TT,32.
PUTSLP:	SETZ	XT,
	MOVE	X,SHPBFR(T4)
	LSHC	X,-4(T2)
	LSH	X,4
	MOVEM	X,CLRS+1(T3)
	MOVEM	XT,CLRS+2(T3)
	ADDI	T3,2
	ADDI	T4,1
	SOJG	TT,PUTSLP
	JRST	CLRSHP

TIME:	4			;REPEAT FRAME TIME (60THS), OR DELAY TIME
	2			;WHEN REALTIME IS SUPPRESSED
	0
	0

TEST:	-1			;TEST-MODE SWITCH, SUPPRESSES REALTIME
OPNIN:	1044,,646471		;TTY INPUT NO-WAIT ECHO AREA
OPNOUT:	15,,646471		;TTY OUTPUT, 3 LINE ECHO AREA

PNTR:	-32.*MAXSHP*NDIREC,,SHPBFR	;DISK INPUT OF SHIPS POINTER

INSHIP:	SETZ			;DISK OPEN INFO FOR SHIPS PATERNS
	SIXBIT	/OPEN/
	[6,,INCH]
	[SIXBIT	/DSK/]
	[SIXBIT	/SWR/]
	[SIXBIT	/SHIPS/]
	SETZ	[SIXBIT	/GJD/]

PNTR1:	-512.,,SIN

INSINE:	SETZ			;DISK OPEN INFO FOR SINE WAVE
	SIXBIT	/OPEN/
	[6,,INCH]
	[SIXBIT	/DSK/]
	[SIXBIT	/SINE/]
	[SIXBIT	/BINARY/]
	SETZ	[SIXBIT	/GJD/]

TVALU:	0			;TV ALU BEFORE CHANGING IT

TVSCRN:	SETZ			;TV MAPPING INFO
	SIXBIT	/CORBLK/
	1000,,600000
	1000,,-1
	TMP
	1000,,-2
	SETZ	TMP2
TMP:	-11,,TVBFR/2000		;8.K TV MEM, START AT PAGE 12 IN PDP10
TMP2:	0

IPX:	40000			;SHIP STARTING POSITIONS
	50000
	50000
IPY:	30000
	40000
	30000
IVX:	300			;SHIP STARTING VELOCITIES
	0
	200
IVY:	0
	250
	100
PX:	BLOCK	MAXSHP		;SHIP DATA DURING A GAME
PY:	BLOCK	MAXSHP
VX:	BLOCK	MAXSHP
VY:	BLOCK	MAXSHP
DIRECT:	BLOCK	MAXSHP
IGRVX:	40000			;SUN STARTING LOCATIONS
	20000
IGRVY:	40000
	40000
GRVX:	BLOCK	MAXSUN		;SUN GAME LOCATIONS
GRVY:	BLOCK	MAXSUN
GRVK:	2			;SUN RELATIVE MASSES
	1
GRAV:	100			;GRAVITY CONSTANT
LEFTF:	4000			;FRINGE POSITIONS, FOR WRAP & BOUNCE
RITEF:	72000
TOPF:	4000
BTMF:	60000
WIDE:	66000			;THE UNIVERSE'S DIMENSIONS
HIGH:	54000
BOUNCE:	0		;-1=BOUNCE, 0=WRAP
RANPOS:	-1		;RANDOM SHIP POSITIONING
RANSUN:	-1		;RANDOM SUN POSITIONING
NSUN:	1		;NUMBER OF SUNS IN THIS GAME
NSHIP:	2		;NUMBER OF SHIPS STARTING THIS GAME
SHPACC:	40		;SHIP ACCELERATION WHEN ENGINES ARE ON
SHPSPN:	20		;RATE OF SPIN WHEN TURNING
XPLODR:	1400		;PROXIMITY FUSE FOR TORPS
XPLDTM:	30		;EXPLOSION TIME
SUNRAD:	1400		;PROXIMITY RADIUS FOR SUNS
TRPVEL:	20		;TORPEDO VELOCITY
TRPLIF:	50		;TORPEDO LIFETIME BEFORE AUTO-DETINATION
RLDTIM:	4		;TORPEDO RELOAD TIME IN FRAMES
SCRTIM:	20		;SCORE DISPLAY TIME AT END OF GAME IN 30ths
MAXVEL:	2000		;MAXIMUM VELOCITY OF THE SHIPS

SWITCH:	BLOCK	MAXSHP	;SHIP COMMAND STORAGE
SHPSTS:	BLOCK	MAXSHP		;0=SHIP NOT ACTIVE, >0=SHIP EXPLODING, -1=SHIP ALIVE
SHOTTM:	BLOCK	MAXSHP		;TORPEDO RELOAD TIME
TALLY:	BLOCK	MAXSHP

CLRS:	BLOCK	MAXSHP*2*40.	;STORAGE BUFFER FOR EACH SHIP ON THE TV

	RADIX	2
SUN:	000000000000000000000000000000000000	;A TYPICAL SUN
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000001000010000000000000000
	000000000000001000100000000000000000
	000000000000100101000111000000000000
	000000000000010110111000000000000000
	000000000000001111000000000000000000
	000000000000001110110000000000000000
	000000000000111010001000000000000000
	000000000011010001000000000000000000
	000000000000100000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000
	000000000000000000000000000000000000


	RADIX 1000

SIN:	BLOCK	512.		;SINEWAVE TABLE, 512. ENTRIES, TO +/-255.

STACK:	BLOCK	20		;STACK AREA, OBVIOUSLY

OBJLEN:	0			;OBJCL POINTER
OBJCL:	BLOCK	MAXOBJ		;STORAGE AREA FOR TORPEDOS

SHPBFR:	BLOCK	32.*MAXSHP*NDIREC

EOM1:	SIXBIT/EOM1/		;A KLUDGE

;THEN COMES THE TV AREA STARTING AT PAGE 12

	END	ST