Used by the routines at ANIMATE_AND_MOVE and MAIN_LOOP.

The author's CHE3D (Krumlinde's Sub_F1E0). The main loop (MAIN_LOOP) calls it once a pass for every record from the knight's on, and the movement code comes back to it at once for an object whose carried-along movement has just stopped (ANIMATE_AND_MOVE). Nothing is done for an object without a sprite, a door (type 1 in +$0C, dealt with where it is met, BUMPED), anything taken out of the room (bit 5 of +$10) or scenery (bits 0-4 of +$10 clear). The labels inside are the author's own.

Otherwise the record's first 19 bytes are copied to IY+$64 on and its address kept at IY+$7D; its state byte, +$0E, is also kept at IY+$67, for the movement code to see bit 7 of it as it was when the pass began. In the first pass after a room is entered (bit 2 of IY+$17) the object is only drawn where it stands (NOG, ANIMATE_AND_MOVE). An object carried along by a movement already under way (bit 7 of +$0E) carries on in the direction kept in +$12 (NOPROP). Otherwise the low four bits of +$0E, its state, say what it does. The states dealt with here:

State 0, at rest: it falls if it can -- the movement code adds the fall -- except that with bit 4 of +$0E, which is cleared as it is read, it makes its last movement (+$0D) once more instead: a thing just dropped (CREATURE_UPDATE) or knocked (OBJECTS_MEET). The pass also notes two kinds of thing as it meets them: the first thing of type 8 (+$0C) is kept at IY+$0F with bit 0 of IY+$11 set, and the creatures in state 9 go for it rather than for the knight (ZOOMIN, ZOOMIN), and destroy it when they reach it (MEET_DECOY); a thing of kind 11 sets bit 1 of IY+$11, which wakes the creature in state 15 (CREATURE_UPDATE). Both are forgotten when a room is entered, a thing is picked up, or the kind-8 thing is destroyed.

State 3 bounces about: it keeps moving along its last movement, $45 (a diagonal) when it has none, and the movement code turns it round when it is blocked. State 4 strikes at the knight when he is in its reach -- its own box moved 12 towards lower +6, towards the viewer -- taking three from LIFE each pass and showing its striking frames (TYPE48_FRAMES); otherwise it is left alone. State 5 is the knight in a jump (KNIGHT_CONTROLS starts one): eight passes going up in the direction he was walking, without the fall, then back to state 8 to come down. State 9 is a creature that rises out of the floor: after a wait it grows through four frames (SPRITEA4B8 to SPRITEA2E4) as +$11 counts up, and then walks after the knight like state 6. Every other state, the knight's 8 among them, goes on to CREATURE_UPDATE.

Bit 7 of IY+$17 is set when the thing of type 5 is used (MAIN_LOOP), and lasts until a room is entered. While it is set every state but the knight's 8 and his jump's 5 is dealt with as state 0: the creatures stand where they are and only fall. Release 1 excepts only state 8 -- at offset 131 it has JR I00 where Release 2 has CP 5 and JR NZ -- and there a knight who jumps while the freeze lasts stays in state 5 for good, since nothing counts his jump down: he never walks again. Played in the simulator in both releases (the type-5 thing in room 24 picked up and used, then SPACE, then Q): Release 1's knight stayed in state 5 and did not move; Release 2's landed after eight passes and walked.