Routines
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64D7: Make a character go to a random location
Used by command lists 0x12, 0x14, 0x1C, 0x28, 0x2A, 0x42, 0x44, 0x4E and 0x58 to make a character go to a place at random. The random locations are arranged in eight groups of four. The group of locations that is suitable for a particular character to choose from is determined by byte 0x24 of the character's buffer.
Input
H Character number (0xB7-0xD1)
64D7 LD L,$24 Point HL at byte 0x24 of the character's buffer
64D9 LD E,(HL) Pick up the contents in E
64DA EX DE,HL
64DB CALL $6291 A=random number
64DE AND $03 A=0xD3, 0xD4, 0xD5 or 0xD6
64E0 ADD A,$D3
64E2 LD H,A Point HL at an entry in the table of random locations
64E3 LD E,$01 Point DE at byte 0x01 of the character's buffer
64E5 LD A,(DE) A=character's x-coordinate
64E6 CP (HL) Is the character already at this x-coordinate?
64E7 JR Z,$64DB Get another random location if so
64E9 LD E,$05 Copy the random location's coordinates into bytes 0x05 and 0x06 of the character's buffer, thus making it his next destination
64EB LDI
64ED LDI
64EF EX DE,HL Transfer the character number back to H
64F0 JP $6469 Send the character on his way
The contents of byte 0x24 of each character's buffer are as follows:
H Character Address Byte
0xB7 Little girl no. 1 B724 0x24
0xB8 Little girl no. 2 B824 0x24
0xB9 Little girl no. 3 B924 0x24
0xBA Little girl no. 4 BA24 0x26
0xBB Little girl no. 5 BB24 0x26
0xBC Little girl no. 6 BC24 0x26
0xBD Little girl no. 7 BD24 0x26
0xBE Little boy no. 1 BE24 0x28
0xBF Little boy no. 2 BF24 0x28
0xC0 Little boy no. 3 C024 0x28
0xC1 Little boy no. 4 C124 0x2A
0xC2 Little boy no. 5 C224 0x2A
0xC3 Little boy no. 6 C324 0x2A
0xC4 Little boy no. 7 C424 0x2A
0xC5 Little boy no. 8 C524 0x2A
0xC6 Little boy no. 9 C624 0x2C
0xC7 Little boy no. 10 C724 0x2C
0xC8 MR WACKER C824 0x30
0xC9 MR WITHIT C924 0x30
0xCA MR ROCKITT CA24 0x44
0xCB MR CREAK CB24 0x44
0xCC MISS TAKE CC24 0x26
0xCD ALBERT CD24 0x2C
0xCE BOY WANDER CE24 0x2E
0xCF ANGELFACE CF24 0x2E
0xD0 EINSTEIN D024 0x2C
0xD1 HAYLEY D124 0x24
The eight groups of random locations used by this routine are:
E D=0xD3 D=0xD4 D=0xD5 D=0xD6
0x24 129,17 144,17 136,17 189,17
0x26 189,17 189,10 170,17 182,3
0x28 38,3 10,10 10,17 66,17
0x2A 38,3 10,17 109,17 75,17
0x2C 112,17 145,17 158,17 37,3
0x2E 189,10 183,17 137,17 72,17
0x30 157,17 38,3 10,17 92,17
0x44 38,3 90,3 10,17 90,17
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