Chase H.Q.: Routine at 8014

8014: Load a stage

Used by the routine at main_loop.
load_stage	8014	LD A,($8007)	Load wanted_stage_number
	8017	LD HL,$A13A	Point HL at current_stage_number
	801A	CP (HL)	Exit if they match
	801B	RET Z	Exit if they match
	801C	LD (HL),A	current_stage_number = wanted_stage_number
	801D	LD ($A220),A	Set dont_draw_screen_attrs to a non-zero value
	8020	ADD A,$B0	Update the level number in "SEARCHING FOR <N>"
	8022	LD ($81AE),A	Update the level number in "SEARCHING FOR <N>"
ls_8025	8025	CALL clear_screen_set_attrs	Call clear_screen_set_attrs
	8028	CALL clear_game_attrs	Call clear_game_attrs
	802B	LD A,$F8	Reverse transition
	802D	CALL setup_transition	Call setup_transition
	8030	LD B,$02
ls_8032	8032	CALL ls_8088	Call ls_8088
ls_load_header	8035	LD IX,$A19C	Load to address &hazards[1] as a temporary scratch area
	8039	LD DE,$0002	Load 2 bytes
	803C	CALL tape_load_at_ix	Call tape_load_at_ix subroutine
	803F	JR NC,ls_load_header	Loop to ls_load_header while failed
	8041	LD HL,$A19C	HL = &hazards[1]
	8044	LD A,(HL)	Are the two loaded bytes equal? [seems odd]
	8045	INC HL
	8046	CP (HL)
	8047	JR NZ,ls_load_header	Loop to ls_load_header if not
	8049	ADD A,$B0	Make it ASCII and terminate it by adding 48+128
	804B	LD ($81BA),A	Set x in "FOUND x"
	804E	LD B,$03
	8050	LD A,($8007)	A = wanted_stage_number
	8053	CP (HL)	equal?
	8054	JR NZ,ls_8032	not the wanted stage
	8056	CALL ls_8088	Call ls_8088
	8059	CALL tape_load_to_5c00	Call tape_load_to_5c00
	805C	JR NC,ls_8025	Jump to ls_8025 if no carry
Success - must have loaded the correct level data.
	805E	XOR A	Set border to black
	805F	OUT ($FE),A	Set border to black
	8061	CALL clear_screen_set_attrs	Call clear_screen_set_attrs
	8064	CALL clear_game_attrs	Call clear_game_attrs
	8067	LD HL,$81BB	HL -> "STOP THE TAPE" message structure
	806A	LD B,$02
	806C	CALL ls_8098	Call ls_8098
	806F	PUSH HL	Preserve ?
Wait for a keypress - debounce.
load_stage_0	8070	CALL keyscan	Call keyscan
	8073	AND $10	Loop while key not pressed
	8075	JR Z,load_stage_0	Loop while key not pressed
load_stage_1	8077	CALL keyscan	Call keyscan
	807A	AND $10	Loop while key pressed
	807C	JR NZ,load_stage_1	Loop while key pressed
	807E	LD A,$08	Forward transition
	8080	CALL setup_transition	Call setup_transition
	8083	POP HL	Restore ?
	8084	LD B,$02	B = 2
	8086	JR ls_8098	Exit via ls_8098
B is passed in.
ls_8088	8088	LD HL,$818C	Point HL at "START TAPE" message structure
	808B	LD A,($8007)	A = wanted_stage_number - 1
	808E	DEC A	A = wanted_stage_number - 1
	808F	JR NZ,ls_8095	Jump if > 0
This entry point is used by the routine at speech_samples_table.
load_stage_2	8091	INC B
	8092	LD HL,$8169	Point HL at tape_messsages
ls_8095	8095	CALL ls_8098	why call adjacent instr? to exec this func twice?
ls_8098	8098	PUSH BC	preserve counter
	8099	PUSH HL	preserve message pointer
ls_809A	809A	LD A,$05	flags byte for print_message
	809C	DEC HL	why dec here?
This entry point is used by the routine at page_in_stage_128k.
ls_809D	809D	CALL print_message	Call print_message
	80A0	DJNZ ls_809A	printing a whole set by looping?
	80A2	CALL transition	Call transition
	80A5	CALL draw_screen	Call draw_screen
	80A8	POP HL	restore message pointer
	80A9	POP BC	restore counter
This entry point is used by the routine at page_in_stage_128k.
load_stage_3	80AA	LD A,($A231)	Load transition_control
	80AD	AND A	Return if zero
	80AE	RET Z	Return if zero
	80AF	LD DE,$0A00	Delay loop
load_stage_4	80B2	DEC DE
	80B3	LD A,D
	80B4	OR E
	80B5	JR NZ,load_stage_4
	80B7	JR ls_8098	Loop