Avalon: Data at EB74

EB74: Data buffer - room co-ordinate data and pointers


EB74	DEFB $00	Maroc's (default) vertical (entry) pixel position when he moves to a new room
EB75	DEFB $00	Maroc's horizontal (entry) position when he moves to a new room, in half-character/4-pixel steps
EB76	DEFB $00	Maroc's vertical (entry) position when he moves to a new room, in pixels, calculated based on the byte stored at EB74
EB77	DEFB $00	Offset for scenery graphics address pointers for 'brick' or 'cavern' type levels (table at 97C3) Offset = 0 for brick level scenery (room number <84) Offset = 12 for 'cavern' level scenery (room number >=84) Offset = 0 for brick level foreground scenery items (room number <83) Offset = 8 for cavern level foreground scenery items (room number >=83)
EB78	DEFB $00	Room item's horizontal position within current room, in half-character (4 pixel) steps
EB79	DEFB $00	Room item's vertical position within current room, in pixels, from top of room area
EB7A	DEFW $0000	Address pointer for room data sets stored at 61A9 Also used to store for ROM memory address pointer used to generate foreground scenery objects at C52A
EB7C	DEFB $00	First room data byte from data banks at 61A9
EB7D	DEFB $00	Multi-purpose byte: Used as a counter to compare with first room data byte (61A9) which holds the room size Tunnel length - byte 1 of tunnel data set at 6710
EB7E	DEFB $00	Multi-purpose: Temporary store for room data bytes at 61A9 Data byte x 4 (used to calculate co-ordinates) subsequently stored here at C21B Counter for number of boundary walls currently on screen in tunnel section
Data relating to doors:
EB7F	DEFB $00	Door byte: 0 = Back wall door 1 = Right wall door 2 = Left wall door
EB80	DEFB $00	Positive/negative offset for door graphic frame (used in routine at CAB4) Indicates number of frames (bits 0-2) and opening/closing direction
EB81	DEFB $00	Pre-graphic data byte including calculated number of animation frames needed for door. Back wall doors have 4 frames, side wall doors have 5. Calculated at C3AB in door calculation routine.