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Routines |
| Prev: 67CC | Up: Map | Next: 67FD |
| 67D8 | LD HL,$5C3B | Prepare HL in case we return to 673A | ||
| 67DB | LD A,($681F) | A=0x6B ('k') if the Kempston joystick is being used, 0x00 otherwise | ||
| 67DE | AND A | Is the Kempston joystick being used? | ||
| 67DF | RET Z | Return if not | ||
| 67E0 | IN A,($1F) | Collect input from the joystick | ||
| 67E2 | AND $1F | Check bits 0-4 | ||
| 67E4 | RET Z | Return with the zero flag set if there was no input | ||
| 67E5 | POP HL | Drop the return address from the stack so we return straight to the caller of 673A | ||
| 67E6 | LD L,A | L=input from the joystick | ||
| 67E7 | BIT 4,L | |||
| 67E9 | LD A,$66 | 0x66='f' (fire catapult) | ||
| 67EB | RET NZ | Return if the fire button was pressed | ||
| 67EC | LD A,$51 | 0x51='Q' (up) | ||
| 67EE | BIT 3,L | |||
| 67F0 | RET NZ | Return if the joystick was moved up | ||
| 67F1 | DEC A | A=0x50: 'P' (right) | ||
| 67F2 | BIT 0,L | |||
| 67F4 | RET NZ | Return if the joystick was moved right | ||
| 67F5 | DEC A | A=0x4F: 'O' (left) | ||
| 67F6 | BIT 1,L | |||
| 67F8 | RET NZ | Return if the joystick was moved left | ||
| 67F9 | LD A,$41 | 0x41='A' (down) | ||
| 67FB | AND A | Reset the zero flag | ||
| 67FC | RET | |||
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