|
Routines |
| Prev: BD15 | Up: Map | Next: BD3E |
|
Used by the routine at check_for_start_game.
One pass: redraws the menu (only its attributes change on screen after the first time), plays the tune if it has not played yet, and reads keys 1 to 5 into E. The control byte is kept in A through the key tests that follow and saved in $5BA6 first, so that check_for_start_game can click when it changes.
|
||||
| menu_loop | BD23 | CALL display_menu | ||
| BD26 | LD DE,menu_tune | menu_tune; $5BD1 makes this a no-op after the first pass | ||
| BD29 | CALL play_audio_wait_key | |||
| BD2C | LD A,$F7 | half-row $F7 is 1 2 3 4 5, key 1 in bit 0 | ||
| BD2E | CALL read_port | |||
| BD31 | LD E,A | |||
| BD32 | LD A,($5BA4) | A = control byte; remember it as it was | ||
| BD35 | LD ($5BA6),A | |||
| BD38 | BIT 0,E | key 1: method 0, keyboard | ||
| BD3A | JR Z,check_for_kempston_joystick | |||
| BD3C | AND $F9 | |||
| Prev: BD15 | Up: Map | Next: BD3E |