Chase H.Q.: Routine at 8258

8258: Attract mode

Used by the routine at start_siren_hook.
attract_mode	8258	LD HL,$5D2B	HL -> attract_data
	825B	CALL set_up_stage	Call set_up_stage
	825E	XOR A	Reset credits/copyright message blinker to show credits
	825F	LD ($828C),A	Reset credits/copyright message blinker to show credits
	8262	LD HL,$0190	Set speed to 400
	8265	LD ($A24A),HL	Set speed to 400
attract_mode_0	8268	CALL keyscan	Call keyscan
	826B	AND $10	Return if fire was pressed
	826D	RET NZ	Return if fire was pressed
	826E	CALL cpu_driver	Call cpu_driver
This entry point is used by the routine at page_in_stage_128k.
attract_mode_1	8271	LD HL,$82A6	HL -> attract mode messages "CHASE HQ" "PRESS GEAR TO PLAY" ...
	8274	LD B,$01	Number of messages?
Blink "PRESS GEAR TO PLAY".
	8276	LD A,$F0	A = <initally $F0, self modified>
	8278	RRCA	Rotate
	8279	LD ($8277),A	Self modify above
	827C	JR C,attract_mode_2	If carry set the hide the final message
	827E	INC B	Otherwise include it
Display 'B' messages.
attract_mode_2	827F	LD A,(HL)	Load flags
	8280	CALL print_message	Call print_message
	8283	DJNZ attract_mode_2	Loop while B > 0
	8285	LD A,($A231)	Jump if transition_control > 0
	8288	AND A
	8289	JR NZ,attract_mode_4
Alternate between credits and copyright messages.
	828B	LD A,$00	Blinking on/off self modified pattern
	828D	XOR $01
	828F	LD ($828C),A
	8292	LD HL,$82CC	HL -> credits_messages
	8295	JR NZ,attract_mode_3	Skip next LD HL based on blink above
	8297	LD HL,$8320	HL -> copyright_messages
attract_mode_3	829A	CALL setup_overlay_messages	Call setup_overlay_messages
attract_mode_4	829D	CALL transition	Call transition
	82A0	CALL draw_screen	Call draw_screen
	82A3	JP attract_mode_0	Loop
attract_messages	82A6	DEFB $03	Flags (double height)
	82A7	DEFB $00	Attribute (black)
	82A8	DEFW $F02C	Back buffer address
	82AA	DEFW $594C	Attribute address
	82AC	DEFM "CHASE H",$D1	"CHASE HQ"
	82B4	DEFB $02	Flags (regular)
	82B5	DEFB $00	Attribute (black)
	82B6	DEFW $F847	Back buffer address
	82B8	DEFW $59A7	Attribute address
	82BA	DEFM "PRESS GEAR TO PLA",$D9	"PRESS GEAR TO PLAY" (this blinks)
credits_messages	82CC	DEFB $0A	Frame delay until the following messages start being shown (0 = 256)
	82CD	DEFB $08	Frame delay until next message?
	82CE	DEFB $02	Flags (regular)
	82CF	DEFB $02	Attribute (red)
	82D0	DEFW $F086	Back buffer address
	82D2	DEFW $5A06	Attribute address
	82D4	DEFM "PROGRAM JOBBEE",$C5	"PROGRAM JOBBEEE"
	82E8	DEFB $08	Frame delay?
	82E9	DEFB $02	Flags (regular)
	82EA	DEFB $02	Attribute (red)
	82EB	DEFW $F0A6	Back buffer address
	82ED	DEFW $5A46	Attribute address
	82EF	DEFM "GRAPHICS BIL",$CC	"GRAPHICS BILL"
	8303	DEFB $28	Delay + stop flags? $28
	8304	DEFB $02	Flags (regular)
	8305	DEFB $02	Attribute (red)
	8306	DEFW noise	Back buffer address
	8308	DEFW $5A86	Attribute address
	830A	DEFM "MUSIC JON DUN",$CE	"MUSIC JON DUNN"
	831E	DEFB $03
	831F	DEFB $00
copyright_messages	8320	DEFB $0A,$08	(Frame delays as credits_messages)
	8322	DEFB $02	Flags (regular)
	8323	DEFB $02	Attribute (red)
	8324	DEFW $F084	Back buffer address
	8326	DEFW $5A04	Attribute address
	8328	DEFM "(C) 1989 OCEAN SOFTWAR",$C5	"(C) 1989 OCEAN SOFTWARE"
	833F	DEFB $08	Frame delay?
	8340	DEFB $02	Flags (regular)
	8341	DEFB $02	Attribute (red)
	8342	DEFW $F0A3	Back buffer address
	8344	DEFW $5A43	Attribute address
	8346	DEFM "(C) 1988 TAITO CORPORATIO",$CE	"(C) 1988 TAITO CORPORATION"
	8360	DEFB $28	Delay + stop flags? $28
	8361	DEFB $02	Flags (regular)
	8362	DEFB $02	Attribute (red)
	8363	DEFW noise	Back buffer address
	8365	DEFW $5A86	Attribute address
	8367	DEFM "ALL RIGHTS RESERVE",$C4	"ALL RIGHTS RESERVED"
	837A	DEFB $03
	837B	DEFB $00