Jetpac: Routine at 630F

630F: Routine at 630F


	630F	LD B,$02	B=$02
	6311	PUSH BC	Stores BC on the stack
	6312	XOR A	Clear A (sets to $00)
	6313	LD ($5DF0),A	CURRENT_LEVEL=A
	6316	LD A,$04	A=Number of lives for 1UP on starting a game
	6318	LD ($5DF1),A	Updates 1UP_CURRENT_LIVES with the number of starting lives
	631B	CALL LEVEL_INIT_3
	631E	CALL LEVEL_INIT_14
	6321	POP BC
	6322	DJNZ $6311	Decrease B by one, jump to 6311 if not zero
	6324	LD A,$05	A=Number of lives for 2UP on starting a game
	6326	LD ($5DF9),A	Updates 2UP_CURRENT_LIVES with the number of starting lives
	6329	LD A,($5CF3)	A=GAME_TYPE
	632C	AND $01	Return if this is a 2UP game
	632E	RET NZ	Return if this is a 2UP game
	632F	LD ($5DF9),A	Sets 2UP_CURRENT_LIVES to zero (as a 1UP game is in progress)
	6332	RET	Return
This entry point is used by the routine at LEVEL_INIT.
	6333	LD HL,$5CF4	HL=1UP_SCORE_1ST
	6336	LD BC,$6000	BC=6000
	6339	CALL CLEAR_PIXELS_0
	633C	CALL $630F
	633F	CALL $698B
	6342	CALL LEVEL_INIT_1
This entry point is used by the routine at 63DA.
	6345	LD SP,$5CF0	Change the stack pointer to HIGH_SCORE
	6348	EI	Enable interrupts
	6349	LD IX,$5D30	IX=5D30
	634D	XOR A	Clear A (sets to $00)
	634E	LD ($5DCB),A	Writes A to 5DCB
This entry point is used by the routine at 63DA.
	6351	LD A,($5C78)
	6354	LD C,A
	6355	LD A,($5DD4)
	6358	CP C
	6359	CALL NZ,$6965
	635C	LD HL,$69A8
	635F	PUSH HL
	6360	LD HL,$6374
	6363	LD A,(IX+$00)
	6366	RLCA
	6367	AND $7E
This entry point is used by the routine at 63DA.
	6369	LD C,A
	636A	LD B,$00
	636C	ADD HL,BC
	636D	LD A,(HL)
	636E	INC HL
	636F	LD H,(HL)
	6370	LD L,A
	6371	JP $5CB0
	6374	DEC DE
	6375	LD L,C
	6376	OR D
	6377	LD (HL),E
	6378	LD (HL),C
	6379	LD (HL),L
	637A	OUT ($6D),A
	637C	RRA
	637D	LD H,L
	637E	PUSH AF
	637F	LD L,H
	6380	CPL
	6381	LD L,H
	6382	JP C,$B163
	6385	LD L,B
	6386	RLCA
	6387	LD H,A
	6388	RST $00
	6389	LD H,(HL)
	638A	EX DE,HL
	638B	LD H,(HL)
	638C	LD D,H
	638D	LD L,B
	638E	LD C,E
	638F	LD L,B
	6390	SBC A,B
	6391	LD H,H
	6392	RST $28
	6393	LD L,D
	6394	CALL M,$6C6F
	6397	LD L,D
This entry point is used by the routine at LEVEL_INIT.
	6398	LD HL,($5CF4)
	639B	LD DE,($5CF7)
	639F	LD A,L
	63A0	LD L,H
	63A1	LD H,A
	63A2	LD A,E
	63A3	LD E,D
	63A4	LD D,A
	63A5	AND A
	63A6	SBC HL,DE
	63A8	JR C,COMPARE_2UP_SCORE
	63AA	JR NZ,COMPARE_1UP_SCORE
	63AC	LD A,($5CF6)	E=1UP_SCORE_3RD
	63AF	LD E,A	E=1UP_SCORE_3RD
	63B0	LD A,($5CF9)	Compare E with 2UP_SCORE_3RD
	63B3	CP E	Compare E with 2UP_SCORE_3RD
	63B4	JR C,COMPARE_1UP_SCORE	Jump if carry flag is set to COMPARE_1UP_SCORE
Tests to see if the highscore has been beaten by 2UP.
COMPARE_2UP_SCORE	63B6	LD HL,$5CF7	HL=2UP_SCORE_1ST
This entry point is used by the routine at UPDATE_HIGHSCORE.
CHECK_HIGHSCORE	63B9	PUSH HL	Push HL onto the stack (see UPDATE_HIGHSCORE)
	63BA	LD DE,$5CF0	DE=HIGH_SCORE
	63BD	LD B,$03	B=$03
	63BF	LD A,(DE)	Compare A against HIGH_SCORE
	63C0	CP (HL)	Compare A against HIGH_SCORE
	63C1	JR C,UPDATE_HIGHSCORE	If it's higher, update the highscore
	63C3	JR NZ,$63C9	Jump if not zero to 63C9 (so if it's less than the current highscore)
	63C5	INC HL	Increase HL by one
	63C6	INC DE	Increase DE by one
	63C7	DJNZ $63BF	Decrease B by one, jump to 63BF if not zero
	63C9	POP HL	Fetch HL off the stack (to clear it)
	63CA	RET	Return