Alien 8: Routine at AE17

Reached through UPDATES. A chamber's socket (SOCKET) is built with a record after it for its sparkle (SOCKET_SPARKLE), which from time to time becomes, for two turns, a picture of the valve the socket takes (graphics 104-107 share the valves' sprites, 96-99), hovering 13 above the socket. Whenever anything lies in the room from the places -- a valve, even a seated one, or an extra life -- it goes, rubbed out and emptied, so a chamber once activated has none.

+10 counts the two turns; then it is the sparkle again (graphic 4 more).

Reached through UPDATES. A chamber's socket (SOCKET) is built with a record after it for its sparkle (SOCKET_SPARKLE), which from time to time becomes, for two turns, a picture of the valve the socket takes (graphics 104-107 share the valves' sprites, 96-99), hovering 13 above the socket. Whenever anything lies in the room from the places -- a valve, even a seated one, or an extra life -- it goes, rubbed out and emptied, so a chamber once activated has none. +10 counts the two turns; then it is the sparkle again (graphic 4 more).
WANTED_VALVE	AE17	CALL DRAW_AT_L12_D5	draw 12 left and 5 down
	AE1A	CALL ANY_SPECIAL_HERE	anything from the places in the room: go
	AE1D	JP NZ,VANISH	anything from the places in the room: go
	AE20	LD A,(IX-$1D)	13 above the socket, the record before
	AE23	ADD A,$0D
	AE25	LD (IX+$03),A
	AE28	DEC (IX+$10)	two turns
	AE2B	RET NZ	two turns
	AE2C	SET 2,(IX+$00)	then the sparkle, redrawn
	AE30	JP SET_WIPE_AND_DRAW_FLAGS	then the sparkle, redrawn