Search

Memory Map

The following is a memory map that was generated based on the MAME source code (.180).  This information is only as accurate as the MAME driver is.  If you see any errors, please let me know what that error is.
 
The Memory Area is related to where the information is from (CPU, Sound Board, etc..), and it may also reflect what it has in common with other hardware.
Big Twin (Playmark, 1995)
Memory Area:bigtwin_main_map
Address RangeLengthFunctionDescription
0x0000-0xFFFFF1048576ROM
0x304000-0x3040012Read/Write NOP(/* watchdog? irq ack? */)
0x440000-0x4403FF1024RAM, Sharedspriteram
0x500000-0x500FFF4096Write, Sharedwbeachvl_fgvideoram_w, videoram2
0x501000-0x501FFF4096Write NOP(/* unused RAM? */)
0x502000-0x503FFF8192Write, Sharedwbeachvl_txvideoram_w, videoram1
0x504000-0x50FFFF49152Write NOP(/* unused RAM? */)
0x510000-0x51000B12Writebigtwin_scroll_w
0x51000C-0x51000D2Write NOP(/* always 3? */)
0x600000-0x67FFFF524288RAM, Sharedbgvideoram
0x700010-0x7000112Read PortSYSTEM
0x0001UnknownActive Low
0x0002UnknownActive Low
0x0004UnknownActive Low
0x0008UnknownActive Low
0x0010Coin 1Active Low
0x0020Coin 2Active Low
0x0040UnknownActive Low
0x0080UnknownActive Low
0x700012-0x7000132Read PortP1
0x0001Joystick UpActive Low
0x0002Joystick DownActive Low
0x0004Joystick LeftActive Low
0x0008Joystick RightActive Low
0x0010Button 1Active Low
0x0020UnknownActive Low
0x0040UnknownActive Low
0x0080Start 1Active Low
0x700014-0x7000152Read PortP2
0x0001Joystick UpActive Low
0x0002Joystick DownActive Low
0x0004Joystick LeftActive Low
0x0008Joystick RightActive Low
0x0010Button 1Active Low
0x0020UnknownActive Low
0x0040UnknownActive Low
0x0080Start 2Active Low
0x700016-0x7000172Writecoinctrl_w
0x70001A-0x70001B2Read PortDSW2
0x0001LanguageActive High
0x0000EnglishActive High
0x0001ItalianActive High
0x0002UnknownActive High
0x0002OffActive High
0x0000OnActive High
0x0000NoActive High
0x0004YesActive High
0x0008OffActive High
0x0000OnActive High
0x0030DifficultyActive High
0x0020EasyActive High
0x0030MediumActive High
0x0010HardActive High
0x0000HardestActive High
0x0040Allow_ContinueActive High
0x0000NoActive High
0x0040YesActive High
0x0080Demo_SoundsActive High
0x0080OffActive High
0x0000OnActive High
0x70001C-0x70001D2Read PortDSW1
0x0001Mode 1Active High
0x0000Mode 2Active High
0x00146C_1CActive High
0x00165C_1CActive High
0x00184C_1CActive High
0x001a3C_1CActive High
0x00028C_3CActive High
0x001c2C_1CActive High
0x00045C_3CActive High
0x00063C_2CActive High
0x001e1C_1CActive High
0x00082C_3CActive High
0x00121C_2CActive High
0x00101C_3CActive High
0x000e1C_4CActive High
0x000c1C_5CActive High
0x000a1C_6CActive High
0x0000Free_PlayActive High
0x00005C_1CActive High
0x00023C_1CActive High
0x00042C_1CActive High
0x00061C_1CActive High
0x00181C_2CActive High
0x00101C_3CActive High
0x00081C_5CActive High
0x00001C_6CActive High
0x00201Active High
0x00002Active High
0x0040UnknownActive High
0x0040OffActive High
0x0000OnActive High
0x0080UnknownActive High
0x0080OffActive High
0x0000OnActive High
0x70001E-0x70001F2Writeplaymark_snd_command_w
0x780000-0x7807FF2048Device Write, Sharedpalette, palette_device, write, palette
0xFF0000-0xFFFFFF65536RAM
 

ROM Map for this game

 
This is the ROM map for the game.  This should tell you what address the ROM is at, how big it is, what it's used for.   
Memory Area:gfx1
Address RangeLengthLabel/LocationDescription
0x0000-0x3FFFF2621444.311CRC(6f628fbc) (Fluke: 3850)
0x40000-0x7FFFF2621445.312CRC(6a9b1752) (Fluke: 7B37)
0x80000-0xBFFFF2621446.313CRC(411cf852) (Fluke: 3FAB)
0xC0000-0xFFFFF2621447.314CRC(635c81fd) (Fluke: C1C5)
Memory Area:gfx2
Address RangeLengthLabel/LocationDescription
0x0000-0x1FFFF1310728.321CRC(2749644d) (Fluke: F9EE)
0x20000-0x3FFFF1310729.322CRC(1d1897af) (Fluke: 5A35)
0x40000-0x5FFFF13107210.323CRC(2a03432e) (Fluke: 40FB)
0x60000-0x7FFFF13107211.324CRC(2c980c4c) (Fluke: 09A4)
Memory Area:oki
Address RangeLengthLabel/LocationDescription
0x0000-0x3FFFF2621441.013CRC(ff6671dc) (Fluke: D9E1)
Memory Area:user1
Address RangeLengthLabel/LocationDescription
0x0000-0x2D4B11596pic16c57-hs_bigtwin_015.hexCRC(c07e9375) (Fluke: 6073)
0x0000-0x2D4B11596pic16c57-hs_bigtwin_015.hexCRC(c07e9375) (Fluke: 6073)
© Copyright 2009-2025, ClassicSoft, LLC. All rights reserved
Powered by the ClassicSoft Web Content Framework V3