; *************************************
; **  THE GAME OF CHASE              **
; **      --FROM DR. DOBBS JOURN   **
; **             MAY 1977          **
; **      --MODIFIED FOR SOL         **
; *************************************
;
;
;
BEGIN:	XRA	A
	STA	YSCORE
	STA	RSCORE
ENTER:	IN	DATA
	LXI	SP,STACK
	CALL	CLEAR
	CALL	SCORE
;
	LXI	H,MS2
	LXI	B,MNAME
	CALL	MSGO
;
DIFF:	LXI	H,MS1
	LXI	B,MDIFF
	CALL	MSGO
	CALL	INP
	ANI	0FH
	STA	DFST
START:	CALL	CLEAR
	CALL	SCORE
	MVI	D,DCORN
	MVI	E,ECORN
TOP:	MVI	B,WIDTH
T1:	CALL	PLOT
	MVI	M,'X'
	INX	D
	CALL	PLOT
	MVI	M,' '
	INX	D
	DCR	B
	JNZ	T1
RSIDE:	MVI	B,HEIGHT
	DCR	E
	DCR	E
R1:	INR	D
	CALL	PLOT
	MVI	M,'X'
	DCR	B
	JNZ	R1
BOTH:	MVI	B,WIDTH-1
B1:	DCR	E
	CALL	PLOT
	MVI	M,' '
	DCR	E
	CALL	PLOT
	MVI	M,'X'
	DCR	B
	JNZ	B1
LSIDE:	MVI	B,HEIGHT
L1:	DCR	D
	CALL	PLOT
	MVI	M,'X'
	DCR	B
	JNZ	L1
;
SEED:	LDA	DFST
	RLC
	MOV	B,A
	MVI	A,1EH
	SUB	B
	MOV	B,A
LOOP1:	CALL	RND
	ANI	0FH
	MOV	D,A
	CALL	RND
	ANI	7FH
	MOV	E,A
	CALL	LIMIT
	JC	LOOP1
	CALL	PLOT
	MOV	A,L
	ANI	0FEH
	MOV	L,A
	MVI	M,'X'
	DCR	B
	JNZ	LOOP1
;
ROSE:	LXI	H,RCORN
	MVI	M,'T'
	LXI	H,RCORN+4
	MVI	M,'Y'
	LXI	H,RCORN+8
	MVI	M,'U'
	LXI	H,RCORN+42H
	MVI	M,5CH
	LXI	H,RCORN+44H
	MVI	M,5EH
	LXI	H,RCORN+46H
	MVI	M,2FH
	LXI	H,RCORN+80H
	MVI	M,'G'
	LXI	H,RCORN+82H
	MVI	M,0DH
	LXI	H,RCORN+84H
	MVI	M,'H'
	LXI	H,RCORN+86H
	MVI	M,09H
	LXI	H,RCORN+88H
	MVI	M,'J'
	LXI	H,RCORN+0C2H
	MVI	M,2FH
	LXI	H,RCORN+0C4H
	MVI	M,0BH
	LXI	H,RCORN+0C6H
	MVI	M,5CH
	LXI	H,RCORN+100H
	MVI	M,'B'
	LXI	H,RCORN+104H
	MVI	M,'N'
	LXI	H,RCORN+108H
	MVI	M,'M'
;
ROBOT:	CALL	SEL
	SHLD	ROB1
	CALL	SEL
	SHLD	ROB2
	CALL	SEL
	SHLD	ROB3
	CALL	SEL
	SHLD	ROB4
	CALL	SEL
	SHLD	ROB5
	CALL	YOU
	JMP	YMOVE
SEL:	CALL	RND
	ANI	0FH
	MOV	D,A
	CALL	RND
	ANI	0FEH
	MOV	E,A
	CALL	LIMIT
	JC	SEL
	CALL	PLOT
	MOV	A,M
	CPI	' '
	JNZ	SEL
	MVI	M,7
	DCR	B
	RNZ
	JMP	YMOVE
;
YOU:	CALL	RND
	ANI	0FH
	MOV	D,A
	CALL	RND
	ANI	0FEH
	MOV	E,A
	CALL	LIMIT
	JC	YOU
	CALL	PLOT
	MOV	A,M
	CPI	' '
	JNZ	YOU
	MVI	M,0FH
	SHLD	YOUP
	RET
;
YMOVE:	CALL	NEAR
YMOV1:	CALL	INP
	LHLD	YOUP
	MVI	M,' '
	CPI	'J'
	CZ	RT
	CPI	'U'
	CZ	UR
	CPI	'Y'
	CZ	UP
	CPI	'T'
	CZ	UL
	CPI	'G'
	CZ	LF
	CPI	'B'
	CZ	LL
	CPI	'N'
	CZ	DN
	CPI	'M'
	CZ	LR
	CPI	'P'
	CZ	PANIC
	CPI	'H'
	JZ	Y1
	MOV	A,M
	CPI	' '
	JNZ	DEATH
Y1:	MVI	M,0FH
	SHLD	YOUP
	CALL	RMOVE
	CALL	END0
	JMP	YMOVE
;
INP:	IN	STAT
	ANI	RDA
	JNZ	INP
	IN	DATA	
	ANI	7FH
	CPI	0DH
	JZ	ENTER
	CPI	1BH
	JZ	BEGIN
	RET
;
RMOVE:	LHLD	ROB1
	CALL	RDEAD
	JC	RMOV1
	CALL	SEEK
	SHLD	ROB1
RMOV1:	LHLD	ROB2
	CALL	RDEAD
	JC	RMOV2
	CALL	SEEK
	SHLD	ROB2
RMOV2:	LHLD	ROB3
	CALL	RDEAD
	JC	RMOV3
	CALL	SEEK
	SHLD	ROB3
RMOV3:	LHLD	ROB4
	CALL	RDEAD
	JC	RMOV4
	CALL	SEEK
	SHLD	ROB4
RMOV4:	LHLD	ROB5
	CALL	RDEAD
	RC
	CALL	SEEK
	SHLD	ROB5
	RET
;
RDEAD:	MOV	A,M
	CPI	'X'
	STC
	RZ
	CMC
	RET
;
CHEK:	MOV	A,M
	CPI	0FH
	JZ	DEATH
	CPI	'X'
	JZ	FLASH
	MVI	M,7
	RET
FLASH:	MVI	D,0A0H
FLAS1:	MVI	M,4
	MVI	E,0FFH
FLAS2:	DCR	E
	JNZ	FLAS2
	MVI	E,0FFH
	MVI	M,84H
FLAS3:	DCR	E
	JNZ	FLAS3
	DCR	D
	JNZ	FLAS1
	MVI	M,'X'
	XRA	A
	RET
;
SEEK:	MVI	M,' '
	PUSH	H
	CALL	SUBH
	POP	H
	CALL	DECH
	PUSH	H
	CALL	SUBV
	POP	H
	CALL	DECV
	JMP	CHEK
;
SUBV:	MOV	A,L
	ANI	0C0H
	MOV	L,A
	XCHG
	LHLD	YOUP
	MOV	A,L
	ANI	0C0H
	SUB	E
	MOV	C,A
	MOV	A,H
	SBB	D
	MOV	B,A
	RET
;
DECV:	RLC
	JC	UP
	MOV	A,C
	RRC
	JC	UP
	XRA	A
	ADD	B
	JNZ	DN
	ADD	C
	JNZ	DN
	RET
;
SUBH:	MOV	A,L
	ANI	3FH
	MOV	L,A
	XCHG
	LHLD	YOUP
	MOV	A,L
	ANI	3FH
	SUB	E
	RET
;
DECH:	RZ
	JP	RT
	JMP	LF
;
DEATH:	MVI	M,0CH
	CALL	MSG2
	LDA	RSCORE
	INR	A
	STA	RSCORE
	CALL	SCORE
	CALL	OVER
	CALL	WAIT
	JMP	START
;
PANIC:	PUSH	PSW
	LDA	DFST
	CPI	9
	JNZ	PAN3
	MVI	C,7
	CALL	RND
	ANA	C
	CPI	1
	JZ	PAN5
	JMP	PAN4
;
PAN5:	PUSH	H
	LHLD	ROB1
	MVI	M,7
	LHLD	ROB2
	MVI	M,7
	LHLD	ROB3
	MVI	M,7
	POP	H
	JMP	PANN
PAN3:	LDA	DFST
	SBI	3
	JP	PAN1
	MVI	C,1
	JMP	PANOK
PAN1:	LDA	DFST
	SBI	6
	MVI	C,3
	JP	PAN2
	JMP	PANOK
PAN2:	MVI	C,7
PANOK:	CALL	RND
	ANA	C
	CPI	1
	JZ	PANN
PAN4:	POP	PSW
	RET
PANN:	CALL	YOU
	POP	PSW
	POP	PSW
	JMP	YMOVE
;
WAIT:	IN	STAT
	ANI	RDA
	JNZ	WAIT
	IN	DATA
	RET
;
OVER:	LDA	RSCORE
	CPI	09H
	JZ	END1
OVER1:	LDA	YSCORE
	CPI	09H
	RNZ
ENDGAME:	CALL	WAIT
	CALL	CLEAR
	LXI	H,ENDM1
	LXI	B,ENDB2
	CALL	MSGO
	LDA	YSCORE
	ADI	30H
	STA	0CD27H
	LDA	RSCORE
	ADI	30H
	STA	0CD29H
	JMP	END2
END1:	CALL	WAIT
	CALL	CLEAR
	LXI	H,ENDM1
	LXI	B,ENDB1
	CALL	MSGO
	LDA	RSCORE
	ADI	30H
	STA	0CD27H
	LDA	YSCORE
	ADI	30H
	STA	0CD29H
END2:	LXI	H,ENDM3
	LXI	B,ENDB3
	CALL	MSGO
END3:	CALL	WAIT
	JMP	BEGIN
;
UP:	LXI	D,0FFC0H
	DAD	D
	RET
DN:	LXI	D,40H
	DAD	D
	RET
LF:	DCX	H
	DCX	H
	RET
RT:	INX	H
	INX	H
	RET
UR:	CALL	UP
	JMP	RT
UL:	CALL	UP
	JMP	LF
LL:	CALL	DN
	JMP	LF
LR:	CALL	DN
	JMP	RT
;
PLOT:	LXI	H,0CC00H
	PUSH	B
VERT:	MOV	A,D
	ANI	0FH
LP1:	MVI	B,40H
LP2:	JZ	HORIZ
	INX	H
	DCR	B
	JNZ	LP2
	DCR	A
	JNZ	LP1
HORIZ:	MOV	A,E
	ANI	7FH
LP3:	JZ	DONE
	INX	H
	DCR	A
	JMP	LP3
DONE:	POP	B
	RET
;
LIMIT:	MOV	A,D
	SBI	LOWD
	STC
	RM
	MOV	A,D
	SBI	HID
	STC
	RP
	MOV	A,E
	SBI	LOWE
	STC
	RM
	MOV	A,E
	SBI	HIE
	STC
	RP
	CMC
	RET
;
RND:	PUSH	B
	PUSH	H
	LXI	H,SH+3
	MVI	B,8
	MOV	A,M
RTOP:	RLC
	RLC
	RLC
	XRA	M
	RAL
	RAL
	DCR	L
	DCR	L
	DCR	L
	MOV	A,M
	RAL
	MOV	M,A
	INR	L
	MOV	A,M
	RAL
	MOV	M,A
	INR	L
	MOV	A,M
	RAL
	MOV	M,A
	INR	L
	MOV	M,A
	RAL
	MOV	M,A
	DCR	B
	JNZ	RTOP
	POP	H
	POP	B
	RET
;
END0:	LHLD	ROB1
	MOV	A,M
	CPI	7
	RZ
	LHLD	ROB2
	MOV	A,M
	CPI	7
	RZ
	LHLD	ROB3
	MOV	A,M
	CPI	7
	RZ
	LHLD	ROB4
	MOV	A,M
	CPI	7
	RZ
	LHLD	ROB5
	MOV	A,M
	CPI	7
	RZ
	JMP	WIN
;
NEAR:	LHLD	YOUP
	CALL	RT
	CALL	NEAR2
	CALL	UP
	CALL	NEAR2
	CALL	LF
	CALL	NEAR2
	CALL	LF
	CALL	NEAR2
	CALL	LF
	CALL	NEAR2
	CALL	DN
	CALL	NEAR2
	CALL	RT
	CALL	NEAR2
	CALL	RT
	CALL	NEAR2
	CALL	MCLEAR
NEAR3:	RET
;
NEAR2:	MOV	A,M
	CPI	7
	RNZ
	CALL	MSG1
	POP	H
	JMP	NEAR3
;
CLEAR:	LXI	H,0CC00H
	MVI	M,' '
	INX	H
	MOV	A,H
	CPI	0D0H
	JNZ	CLEAR+3
	XRA	A
	OUT	0FEH
	RET
;
MSG1:	PUSH	H
	PUSH	B
	LXI	H,MS1
	LXI	B,M1
	CALL	MSGQ
	POP	B
	POP	H
	RET
;
MSG2:	LXI	H,MS1
	LXI	B,M2
	CALL	MSGQ
	RET
;
WIN:	LXI	H,MS1
	LXI	B,MWIN
	CALL	MSGQ
	LDA	YSCORE
	INR	A
	STA	YSCORE
	CALL	SCORE
	CALL	OVER
	CALL	WAIT
	JMP	START
;
SCORE:	LXI	H,SRE
	LXI	B,MSR
	CALL	MSGO
	LDA	YSCORE
	ADI	30H
	LXI	H,SCR
	MOV	M,A
	LDA	RSCORE
	ADI	30H
	LXI	D,40H
	DAD	D
	MOV	M,A
	LXI	H,MSY
	LXI	B,MSR1
	CALL	MSGO
	LXI	H,MT1
	LXI	B,MSR2
	CALL	MSGO
	RET
;
MCLEAR:	PUSH	H
	PUSH	B
	LXI	H,MS1
	MVI	C,20H
MCL1:	MVI	M,' '
	INX	H
	DCR	C
	JNZ	MCL1
	POP	B
	POP	H
	RET
;
MSGO:	LDAX	B
	CPI	 0FFH
	RZ
	MOV	M,A
	INX	B
	INX	H
	JMP	MSGO
;
MSGQ:	LDAX	B
	CPI	0FFH
	RZ
	ORI	80H
	MOV	M,A
	INX	B
	INX	H
	JMP	MSGQ
;
;
;
MNAME:	DB	'* * * THE GAME OF CHASE * * *'
	DB	0FFH
M1:	DB	' CAUTION - ROBOT NEAR! '
	DB	0FFH
M2:	DB	' YOU HAVE BEEN DESTROYED! '
	DB	0FFH
MWIN:	DB	' CONGRATULATIONS - YOU HAVE WON! '
	DB	0FFH
MSR:	DB	'--SCORE--'
	DB	0FFH
MSR1:	DB	'YOU:'
	DB	0FFH
MSR2:	DB	'ROBOTS:'
	DB	0FFH
ENDB1:	DB	'THE ROBOTS HAVE WON -   :'
	DB	0FFH
ENDB2:	DB	'YOU HAVE BEATEN THEM -  :'
	DB	0FFH
ENDB3:	DB	'HIT ANY KEY TO PLAY AGAIN.....'
	DB	0FFH
MDIFF:	DB	' LEVEL OF DIFFICULTY (0-9)?'
	DB	0FFH
;
;
STAT	EQU	0FAH
DATA	EQU	0FCH
RDA	EQU	1
STACK	EQU	0650H
RCORN	EQU	0CCF6H
DCORN	EQU	0
ECORN	EQU	2
HEIGHT	EQU	0DH
WIDTH	EQU	19H
LOWD	EQU	DCORN+1
LOWE	EQU	ECORN+1
HID	EQU	DCORN+HEIGHT-1
HIE	EQU	LOWE+WIDTH+WIDTH-4
MS1	EQU	0CFCCH
MS2	EQU	0CD10H
SCR	EQU	0CFBDH
SRE	EQU	0CF77H
MSY	EQU	0CFB8H
MT1	EQU	0CFF5H
ENDM1	EQU	0CD10H
ENDM3	EQU	0CD90H
SH:	DW	1234H
	DW	5678H
DFST:	DB	1
RSCORE	DS	1
YSCORE	DS	1
YOUP	DS	2
ROB1	DS	2
ROB2	DS	2
ROB3	DS	2
ROB4	DS	2
ROB5	DS	2
END