Omega Race Memory Map Version 1.1 (Jul 24,1997) --------------------- Main CPU clock rate: 3Mhz Main CPU intr rate: 240Hz Sound CPU clock rate: 1.5Mhz 0000 - 3fff PROM 4000 - 4bff RAM (3k) 5c00 - 5cff NVRAM (256 x 4bits) 8000 - 8fff Vec RAM (4k) 9000 - 9fff Vec ROM (4k) 15 14 13 12 11 10 --+--+--+--+--+-- 0 0 0 0 M8 - 2732 (4k) 0 0 0 1 L8 - 2732 0 0 1 0 K8 - 2732 0 0 1 1 J8 - 2732 0 1 - 0 0 0 RAM (3k) 0 1 - 0 0 1 0 1 - 0 1 0 0 1 - 1 1 1 4 Bit BB RAM (d0-d3) 1 - - 0 0 Vec RAM (4k) 1 - - 0 1 1 - - 1 0 Vec ROM (2k) E1 1 - - 1 1 Vec ROM (2k) F1 I/O Ports 8 Start/ (VG start) 9 WDOG/ (Reset watchdog) A SEQRES/ (VG stop/reset?) B RDSTOP/ d7 = stop (VG running if 0) 10 I DIP SW C4 (game ship settings) 6 5 4 3 2 1 1st bonus ship at | | | | 0 0 40,000 | | | | 0 1 50,000 | | | | 1 0 70,000 | | | | 1 1 100,000 | | | | 2nd and 3rd bonus ships | | 0 0 150,000 250,000 | | 0 1 250,000 500,000 | | 1 0 500,000 750,000 | | 1 1 750,000 1,500,000 | | ships per credit 0 0 1 credit = 2 ships / 2 credits = 4 ships 0 1 1 credit = 2 ships / 2 credits = 5 ships 1 0 1 credit = 3 ships / 2 credits = 6 ships 1 1 1 credit = 3 ships / 2 credits = 7 ships 11 I 7 = Test 6 = P1 Fire 5 = P1 Thrust 4 = Tilt 1 = Coin 2 0 = Coin 1 12 I 7 = 1P1CR 6 = 1P2CR 3 = 2P2CR -+ 2 = 2P1CR | 1 = P2Fire | 0 = P2Thr -+ cocktail only 13 O 7 = 6 = screen reverse 5 = 2 player 2 credit start LED 4 = 2 player 1 credit start LED 3 = 1 player 1 credit start LED 2 = 1 player 1 credit start LED 1 = coin meter 2 0 = coin meter 1 14 O sound command (interrupts sound Z80) 15 I encoder 1 (d7-d2) The encoder is a 64 position Grey Code encoder, or a pot and A to D converter. Unlike the quadrature inputs on Atari and Sega games, Omega Race's controller is an absolute angle. 0x00, 0x04, 0x14, 0x10, 0x18, 0x1c, 0x5c, 0x58, 0x50, 0x54, 0x44, 0x40, 0x48, 0x4c, 0x6c, 0x68, 0x60, 0x64, 0x74, 0x70, 0x78, 0x7c, 0xfc, 0xf8, 0xf0, 0xf4, 0xe4, 0xe0, 0xe8, 0xec, 0xcc, 0xc8, 0xc0, 0xc4, 0xd4, 0xd0, 0xd8, 0xdc, 0x9c, 0x98, 0x90, 0x94, 0x84, 0x80, 0x88, 0x8c, 0xac, 0xa8, 0xa0, 0xa4, 0xb4, 0xb0, 0xb8, 0xbc, 0x3c, 0x38, 0x30, 0x34, 0x24, 0x20, 0x28, 0x2c, 0x0c, 0x08 16 I encoder 2 (d5-d0) The inputs aren't scrambled as they are on the 1 player encoder 17 I DIP SW C6 (coin/cocktail settings) 8 7 6 5 4 3 2 1 coin switch 1 | | | | | 0 0 0 1 coin 2 credits | | | | | 0 0 1 1 coin 3 credits | | | | | 0 1 0 1 coin 5 credits | | | | | 0 1 1 4 coins 5 credits | | | | | 1 0 0 3 coins 4 credits | | | | | 1 0 1 2 coins 3 credits | | | | | 1 1 0 2 coins 1 credit | | | | | 1 1 1 1 coin 1 credit | | | | | | | | | | coin switch 2 | | 0 0 0 1 coin 2 credits | | 0 0 1 1 coin 3 credits | | 0 1 0 1 coin 5 credits | | 0 1 1 4 coins 5 credits | | 1 0 0 3 coins 4 credits | | 1 0 1 2 coins 3 credits | | 1 1 0 2 coins 1 credit | | 1 1 1 1 coin 1 credit | | | 0 coin play | 1 free play | 0 normal 1 cocktail display list format: (4 byte opcodes) +------+------+------+------+------+------+------+------+ |DY07 DY06 DY05 DY04 DY03 DY02 DY01 DY00 | 0 +------+------+------+------+------+------+------+------+ |OPCD3 OPCD2 OPCD1 OPCD0 DY11 DY10 DY09 DY08 | 1 OPCD 1111 = ABBREV/ +------+------+------+------+------+------+------+------+ |DX07 DX06 DX05 DX04 DX03 DX02 DX01 DX00 | 2 +------+------+------+------+------+------+------+------+ |INTEN3 INTEN2 INTEN1 INTEN0 DX11 DX10 DX09 DX08 | 3 +------+------+------+------+------+------+------+------+ Draw relative vector 0x80 1000YYYY YYYYYYYY IIIIXXXX XXXXXXXX Draw relative vector and load scale 0x90 1001YYYY YYYYYYYY SSSSXXXX XXXXXXXX Beam to absolute screen position 0xA0 1010YYYY YYYYYYYY ----XXXX XXXXXXXX Halt 0xB0 1011---- -------- Jump to subroutine 0xC0 1100AAAA AAAAAAAA Return from subroutine 0xD0 1101---- -------- Jump to new address 0xE0 1110AAAA AAAAAAAA Short vector draw 0xF0 1111YYYY IIIIXXXX Sound Z80 Memory Map 0000 ROM 1000 RAM 15 14 13 12 11 10 0 2k prom (K5) 1 2k prom (J5) 1 1k RAM (K4,J4) I/O (write-only) 0,1 8912 (K3) 2,3 8912 (J3) I/O (read-only) 0 input port from main CPU. main CPU writing port generated INT Sound Commands: 0 - reset sound CPU