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Routines |
| Prev: 8B1F | Up: Map | Next: 8C3D |
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Used by the routine at 8B34.
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| 8B90 | CALL $8C3D | Check for collision. | ||
| 8B93 | LD IX,$8D52 | Point IX at the room flags (8D52). | ||
| 8B97 | LD IY,$8D54 | Point IY at the direction flags (8D54). | ||
| 8B9B | LD A,(IX+$00) | Clear all bits except 2 and 4 on the room flags. | ||
| 8B9E | AND $0A | |||
| 8BA0 | LD (IX+$00),A | |||
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Check the movement flags.
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| 8BA3 | LD A,(IY+$00) | Can Monty move up? | ||
| 8BA6 | OR A | |||
| 8BA7 | JR NZ,$8BAD | Jump forward if so. | ||
| 8BA9 | SET 7,(IX+$00) | Set bit 7 of the room flags - Monty can't move up. | ||
| 8BAD | LD A,(IY+$01) | Can Monty move down? | ||
| 8BB0 | OR A | |||
| 8BB1 | JR NZ,$8BB7 | Jump forward if so. | ||
| 8BB3 | SET 6,(IX+$00) | Set bit 6 of the room flags - Monty can't move down. | ||
| 8BB7 | LD A,(IY+$02) | Can Monty move left? | ||
| 8BBA | OR A | |||
| 8BBB | JR NZ,$8BC1 | Jump forward if so. | ||
| 8BBD | SET 5,(IX+$00) | Set bit 5 of the room flags - Monty can't move left. | ||
| 8BC1 | LD A,(IY+$03) | Can Monty move right? | ||
| 8BC4 | OR A | |||
| 8BC5 | JR NZ,$8BCB | Jump forward if so. | ||
| 8BC7 | SET 4,(IX+$00) | Set bit 4 of the room flags - Monty can't move right. | ||
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Check to see if there is a nasty in the proximity.
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| 8BCB | CP $01 | Is a nasty to the right of Monty? | ||
| 8BCD | JP Z,$946E | If so, Monty dies. | ||
| 8BD0 | LD A,(IY+$02) | Is a nasty to the left of Monty? | ||
| 8BD3 | CP $01 | If so, Monty dies. | ||
| 8BD5 | JR Z,$8BCD | |||
| 8BD7 | LD A,(IY+$01) | Is a nasty below Monty? | ||
| 8BDA | CP $01 | If so, Monty dies. | ||
| 8BDC | JR Z,$8BCD | |||
| 8BDE | LD A,(IY+$00) | Is a nasty above Monty? | ||
| 8BE1 | CP $01 | If so, Monty dies. | ||
| 8BE3 | JR Z,$8BCD | |||
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See if Monty can climb here.
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| 8BE5 | PUSH IY | Remember IY. | ||
| 8BE7 | CALL $FEA2 | Can Monty climb here? | ||
| 8BEA | JR NZ,$8BF0 | Jump forward if not. | ||
| 8BEC | SET 2,(IX+$00) | Set bit 2 of the room flags - Monty can climb. | ||
| 8BF0 | POP IY | Restore IY. | ||
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See if Monty has collided with non-empty space.
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| 8BF2 | LD B,$02 | |||
| 8BF4 | LD A,($5C7B) | Get the bottom 3 bits of the X co-ordinate. | ||
| 8BF7 | AND $07 | |||
| 8BF9 | JR Z,$8BFD | Move forward if they are zero. | ||
| 8BFB | LD B,$03 | Scan 3 rows. | ||
| 8BFD | CALL $8D5F | Get the current screen address in HL. | ||
| 8C00 | LD C,$00 | Set C as no bits found. | ||
| 8C02 | LD A,(HL) | Get the next data from screen. | ||
| 8C03 | OR C | OR it against C to retain any bits found. | ||
| 8C04 | LD C,A | Store this result back in C. | ||
| 8C05 | INC HL | Move to the next column. | ||
| 8C06 | DJNZ $8C02 | Loop back if there are more columns to look at. | ||
| 8C08 | LD A,C | Was anything found at this screen address? | ||
| 8C09 | OR A | |||
| 8C0A | JP Z,$8B0C | If not, set various flags. | ||
| 8C0D | BIT 7,(IX+$01) | Is Monty in mid-air? | ||
| 8C11 | RET Z | Return if so. Monty has reached the ground after falling. | ||
| 8C12 | RES 7,(IX+$01) | Reset the mid-air flag. | ||
| 8C16 | RES 0,(IX+$00) | Enable background objects to move. | ||
| 8C1A | RES 1,(IX+$00) | Set that Monty is not jumping. | ||
| 8C1E | LD A,($8D58) | Get the height fallen. | ||
| 8C21 | CP $20 | Is it above 20? | ||
| 8C23 | JP NC,$946E | Yes, Monty has fallen too far, so he's dead. | ||
| 8C26 | XOR A | Set A to 0 to reset some flags. | ||
| 8C27 | LD ($8D58),A | Reset the height fallen. | ||
| 8C2A | LD ($848F),A | Reset the position jumped off ground. | ||
| 8C2D | LD ($8498),A | Reset the time being jumped. | ||
| 8C30 | LD HL,$869C | Reset the pointer to the movement table back to 869C. | ||
| 8C33 | LD ($8492),HL | |||
| 8C36 | LD HL,($8496) | Reset the pitch to sound when jumping back to the default. | ||
| 8C39 | LD ($8494),HL | |||
| 8C3C | RET | Return. | ||
| Prev: 8B1F | Up: Map | Next: 8C3D |