Used by the routine at START.

Called by START before every game. It stops every line's flash, clears the buffer, draws the menu's text and frame (DISPLAY_MENU, which draws the frame and shows the buffer only the first time, as the flag cleared here tells it) and flashes the chosen control method (FLASH_MENU). Then round a loop: print the text again (its attributes, with the flashing, go straight to the screen), play the tune if it has not been heard (PLAY_TUNE_ONCE, which a key cuts short), and read the keys.

Keys 1 to 4 set bits 1 and 2 of CONTROL to 0 keyboard, 1 Kempston, 2 cursor, 3 Interface II, and key 0 starts the game. If several are held the highest wins, since each is applied in turn. Key 5 is not read, and nothing here sets bit 3 of CONTROL, though FLASH_MENU flashes a sixth line of the menu when it is set.

Two leftovers do nothing: HL is loaded with one variable's address and at once with another's, and the CP after them sets flags nothing reads -- perhaps a test, once, for whether the choice had changed.