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Routines |
| Prev: F22A | Up: Map | Next: F26C |
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Makes two new random numbers at RandomNumbers, using a pointer to a byte of memory that is moved on one place each time and stays below B000. The byte that it points to is added to each number, together with the value of the value of the controls (see ReadControls), so pressing the controls at different times changes the numbers.
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| RandomNumber | F23B | LD IX,$9BCB | The random numbers. | |
| F23F | LD H,(IX+$02) | Read offset 02 of IX into H. | ||
| F242 | LD L,(IX+$03) | Read offset 03 of IX into L. | ||
| F245 | INC HL | Advance HL. | ||
| F246 | LD A,H | A=H. | ||
| F247 | AND %10101111 | Keep the bits of A that are set in AF. | ||
| F249 | LD (IX+$02),A | Write A to offset 02 of IX. | ||
| F24C | LD (IX+$03),L | Write L to offset 03 of IX. | ||
| F24F | LD B,(HL) | Read HL into B. | ||
| F250 | LD A,($5C37) | The controls. | ||
| F253 | ADD A,B | A gains B. | ||
| F254 | ADD A,$05 | Add 05 to A. | ||
| F256 | ADD A,(IX+$00) | Add the byte at offset 00 of IX to A. | ||
| F259 | LD (IX+$00),A | Write A to offset 00 of IX. | ||
| F25C | LD A,B | A=B. | ||
| F25D | CPL | Invert A. | ||
| F25E | LD B,A | B=A. | ||
| F25F | LD A,($5C37) | The controls. | ||
| F262 | ADD A,$09 | Add 09 to A. | ||
| F264 | ADD A,B | A gains B. | ||
| F265 | ADD A,(IX+$01) | Add the byte at offset 01 of IX to A. | ||
| F268 | LD (IX+$01),A | Write A to offset 01 of IX. | ||
| F26B | RET | Return. | ||
| Prev: F22A | Up: Map | Next: F26C |