Document Title: [OmegaRace.html (html file)]
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
