Sprite Color Sets

ROM	Size	Content	Ofs	CRC	SHA1
mpc-2.2h	256	spr_clut	0	7ae4cd97	bc0662fac82ffe65f02092d912b2c2b0c7a8ac2b

The lower 6 bits of the 2nd byte of the sprite structure contains a color-set value. Thus there could be 64 color-set's (00..3F). The Moon Patrol hardware appears to mask off the upper bit making 32 color-sets (00..1F) with set 0x20 masking to 0x00.

This PROM describes what color values goes in what color sets. There are 8 bytes per color set, but only the first 4 colors are used (sprite pixels are 2-bits ... 4 colors).

MoonPatrol only defines 16 color sets (00..0F).

Each byte here is an offset into the PROM3 color definition. For instance the first 4 bytes in the table below describe the 4 colors for color-set-0: 0, 1, 2, 3. Looking these up in PROM3 yields color values 00 (transparent), 01 (near black), C6 (red/violet), and 37 (turquoise). Color-set-1 is made of colors values from PROM3 at addresses 0, 4, 2, and 5.

;                  Pixel value:  00   01   10   11
0000: 00 01 02 03 00 00 00 00 ; ----                Color set 0
0008: 00 04 02 05 00 00 00 00 ; ----                1
0010: 00 05 06 07 00 00 00 00 ; ----                2
0018: 00 07 08 09 00 00 00 00 ; ----                3
0020: 00 0A 00 0B 00 00 00 00 ; ----      ----      4
0028: 00 00 00 00 00 00 00 00 ; ---- ---- ---- ---- 5
0030: 00 00 00 00 00 00 00 00 ; ---- ---- ---- ---- 6
0038: 00 09 0E 05 00 00 00 00 ; ----                7
0040: 00 05 03 0F 00 00 00 00 ; ----                8
0048: 00 09 01 05 00 00 00 00 ; ----                9
0050: 00 01 08 00 00 00 00 00 ; ----           ---- A
0058: 00 01 05 00 00 00 00 00 ; ----           ---- B
0060: 00 01 05 03 00 00 00 00 ; ----                C
0068: 00 04 0D 05 00 00 00 00 ; ----                D
0070: 00 05 00 05 00 00 00 00 ; ----      ----      E
0078: 00 00 05 05 00 00 00 00 ; ---- ----           F
;
; Transparent (not used) here down
;
0080: 00 00 00 00 00 00 00 00 ; 10
0088: 00 00 00 00 00 00 00 00 ; 11
0090: 00 00 00 00 00 00 00 00 ; 12
0098: 00 00 00 00 00 00 00 00 ; 13
00A0: 00 00 00 00 00 00 00 00 ; 14
00A8: 00 00 00 00 00 00 00 00 ; 15
00B0: 00 00 00 00 00 00 00 00 ; 16
00B8: 00 00 00 00 00 00 00 00 ; 17
00C0: 00 00 00 00 00 00 00 00 ; 18
00C8: 00 00 00 00 00 00 00 00 ; 19
00D0: 00 00 00 00 00 00 00 00 ; 1A
00D8: 00 00 00 00 00 00 00 00 ; 1B
00E0: 00 00 00 00 00 00 00 00 ; 1C
00E8: 00 00 00 00 00 00 00 00 ; 1D
00F0: 00 00 00 00 00 00 00 00 ; 1E
00F8: 00 00 00 00 00 00 00 00 ; 1F