Jet Set Willy: Routine at 8DC0

| Routines

8DC0: Copy a room attribute byte into the buffer at 5E00

Used by the routine at 8D6B. On entry, A holds a room layout byte, rotated such that the bit-pair corresponding to the tile of interest is in bits 0 and 1.
Input
A | Room layout byte (rotated)
IX | Attribute buffer address (5E00-5FFF)
8DC0 | AND $03 | Keep only bits 0 and 1; A=0 (background), 1 (floor), 2 (wall) or 3 (nasty)
8DC2 | LD C,A | Multiply by 9 and add 0xA0; now A=0xA0 (background), 0xA9 (floor), 0xB2 (wall) or 0xBB (nasty)
8DC3 | RLCA
8DC4 | RLCA
8DC5 | RLCA
8DC6 | ADD A,C
8DC7 | ADD A,$A0
8DC9 | LD E,A | Point DE at the attribute byte for the background, floor, wall or nasty tile (see 80A0)
8DCA | LD D,$80
8DCC | LD A,(DE) | Copy the attribute byte into the buffer at 5E00
8DCD | LD (IX+$00),A
8DD0 | INC IX | Move IX along to the next byte in the attribute buffer
8DD2 | RET |