Used by the routines at LEAPER, REMOTE_ROBOT, REMOTE_PAD, REMOTE_BUTTON, SHUTTLE_U, CONVEYOR_PLUS_V, COLLAPSING_BLOCK, STILL_DEADLY, DROPPING_BLOCK, PUSHABLE and LIFT.

A note for all the nudge routines from here to DRAW_AT_L8_D2: +$12 and +$13 of an object record are added to the pixel position the projection (CALC_PIXEL_XY) works out from the object's U, V and Z, to line the sprite up with the object's position. X is pixels right and Y pixels up, so the usual negative values move the sprite left and down. For a still object that is all its update routine does; others call one to set the nudge before they move. They all end at SET_PIXEL_ADJ, in DRAW_AT_L4_D3. Knight Lore calls these drawing offsets.

This one is the whole update routine for graphic 30 (UPDATES), the only piece of object template 1 and of backgrounds 12 and 13, and is called by the update routines of graphics 28, 44, 45, 47, 66, 68, 72, 75, 122 to 128 and 130.