| Chase H.Q. | Routines |
| Prev: FBC8 | Up: Map | Next: FC29 |
|
Samples the Kempston port ($1F) $14=20 times, servicing sound each iteration (run_title_tune), and bails out to the main poll loop (omd_service_and_read_keys) as soon as the port's value changes (i.e. a joystick is moving/present); otherwise falls through to run_title_tune_4 with A=1 (no joystick detected).
Used by the routine at options_menu_driver.
|
||||
| detect_kempston_joystick | FC14 | LD B,$14 | ||
| FC16 | IN A,($1F) | |||
| FC18 | LD C,A | |||
| detect_kempston_joystick_0 | FC19 | IN A,($1F) | ||
| FC1B | CP C | |||
| FC1C | JR NZ,omd_service_and_read_keys | |||
| FC1E | PUSH BC | |||
| FC1F | CALL run_title_tune | |||
| FC22 | POP BC | |||
| FC23 | DJNZ detect_kempston_joystick_0 | |||
| FC25 | LD A,$01 | |||
| FC27 | JR run_title_tune_4 | |||
| Prev: FBC8 | Up: Map | Next: FC29 |