32 column by 25 row tile buffer. Clear_PlayArea clears it, and the print utilities write through it when drawing a room.

Attribute bytes matching Buffer_RoomTiles.

Non-zero while the player is jumping or falling.

Set when a life is lost so Handler_Player can restart the room.

Offset into Buffer_RoomTiles calculated by Convert_Coordinate.

Inclusive min/max row and column used by the clipped print routines. Defaults to rows 2-24 and columns 1-33.

Populated by Unpack_Rooms. See Player_Action for usage.

Populated by Unpack_Rooms. See Player_Action_DoorLoop for usage.

Three-byte 255-terminated records. See Handler_Collectibles.

Two-byte 255-terminated records. See Handler_InventoryItems.

Populated by Unpack_Rooms. See Player_ClimbDown and Player_ClimbUp.

19-byte records drawn by Handler_MovingObjects.

13-byte records handled by Handler_Actors.

14-byte records handled by Handler_Enemies.

3 means the player has touched an actor.

Counts falling frames; a hit starts when it reaches 10.

Three-byte shifted collision mask from Build_PlayerMask.

Used by the room-7 bats and the room-22 special.

Walks the Data_TuneStream stream. Play_Tune reads one byte at a time.

Walks the Data_TuneStreamCopy stream in step with Pointer_TuneData.

Counts to 5 in Handler_Interrupts before the tune is allowed to play.

0 on the introduction/menu. 255 after the intro timeout so Initialise_Game starts a game.

16-bit countdown used by the introduction and demo timeout.

When set, Play_Tune returns through the delay routine instead of playing a note.

Set to 255 by Handler_Housekeeping when all four collection slots hold 9.

0 is keyboard. Non-zero selects Kempston (and the define-keys highlight).

Five KEY_SCAN codes copied from Table_DefaultKeys. Order: left, right, up, down, action.

Default 1/2 (right/left) written by Unpack_Rooms.

Bit 7 set means nothing is being carried. Drawn by Handler_CarriedObject.

Counts down; when it hits 0 Handler_EventTimer fires *PendingEvent.

Room IDs run from 0 to 22.

Player entity used as IX by Handler_Player.

Initialised to 4 by Unpack_Rooms.

Four digits shown on room 0. 9 in every slot sets GameCompleteFlag.

One pointer per room, filled by Unpack_Rooms from Data_Rooms.

Working copy of the 23 packed rooms. See Unpack_Rooms.