• Disclaimers
• New in This Version
• History
• Introduction
• VGBA Ports
• Registered Users
• What is Included
• What is not Included
• Buttons
• Command Line Options
• Frequently Asked Questions
• Notes to Demo Authors
• Thanks

• GameBoy and GameBoy Advance are registered trademarks of Nintendo.
• The author is in no way affiliated with Nintendo.
• The author is in no way affiliated with any pirate group out there.
• The author cannot and will not provide you with any GameBoy or GameBoy Advance games.
• The author cannot be held responsible for anything this program will do to your computer, brains, free time, housemates, pets, or family members.

• VGBA-Windows is now available. Register it NOW!
• VGBA-Unix is now available.
• Added facility to save and load emulation state.
• Added serial EEPROM emulation.
• Implemented more or less accurate CPU cycle counting (still not accurate enough though).
• Implemented HuffUncomp() call.
• Fixed ObjAffineSet(), CpuSet(), CpuFastSet(), and SoftReset() calls.
• Fixed timers to reload values correctly.
• Majorly updated documentation.
• Fixed background color problem in the non-VESA (256 color) version of VGBA-MSDOS.

New in Version 0.6

• Added JEDEC FlashROM support.
• Added CRC/CMP check. All failing cartridges will now be rejected unless you use the -nocrc option.
• Implemented pending IRQ handling after IRQs were switched on.
• Disabled IRQs in the SVC mode.
• Added ObjAffineSet() BIOS call.
• Added Halt() and Stop() BIOS calls.
• Fixed several BIOS calls.
• Fixed a special case of DMA with the length of 0 items.
• Fixed LDR/STR/LDRB/STRB instruction display in the debugger.
• Improved cartridge information reporting.
• Added a lot of command line options.
• Added a lot of control keys.

New in Version 0.5

• Moved dummy GBA.ROM contents inside the VGBA code.
• Added DMA3 start at the beginning of HRefresh.
• Added 'v' command to the debugger to show GBA status.
• Fixed transparency effects in bitmap modes.
• Fixed transparency with multiple backgrounds.
• Now initializing rotation/scaling properly.
• No longer supporting 128kB flash ROM above the cartridge ROM.

New in Version 0.4

• Added MULL/MLAL ARM opcodes.
• Added color effects to all screen modes.
• Added rotation to all appropriate screen modes.
• Added rotation to sprites.
• Fixed DMA transfers to start correctly.
• Fixed DMA transfers to leave correct values in DMACONT registers.
• Added IRQ at the end of DMA transfer, if required.
• Fixed GB sound chip emulation.
• Added CPUSet() and CPUFastSet() BIOS calls.
• Added RLUnCompWRAM() and RLUnCompVRAM() BIOS calls.
• Now saving cartridge SRAM and flash ROM into a .SAV file.
• Both 16bit color and 8bit color versions are included. 16bit version requires VESA-compatible video card. I still recommend it over the 8bit version as GBA programs are extremely ugly in 256 colors :)

VGBA is a logical continuation of my previous work on the videogame console emulators, namely, the Virtual GameBoy (GameBoy Classic, GameBoy Pocket, Super GameBoy, and GameBoy Color emulator). VGBA is completely different from VGB though. It will not run original GameBoy software, you will have to use VGB for that.

I am mainly releasing this version of VGBA for game developers and demo programmers who would like to start coding for GBA but cannot afford to buy an official development kit from Nintendo. VGBA is not a replacement for the real development kit though, as it does not emulate all GBA features. I hope that the number of supported features will increase with time and your help.

Windows 95/98/ME/NT/2000

The Windows version of VGB is available from me, Marat Fayzullin, for $35US. This fee ensures that you will get you the latest full version of VGBA-Windows with free updates via email as long as VGBA-Windows is being updated. For more information about it, take a look at

http://www.komkon.org/fms/VGBA/VGBAWindows.html

You can register VGBA-Windows by one of the following methods:

ORDER BY MAIL

Send $35US in cash, money order, or a US bank check to:

     Marat Fayzullin
     6304 Hampton Place
     Elkridge, MD 21075
     USA

Don't forget to include your email address and mention that you want VGBA-Windows, as I'm selling several other products as well. The software will be emailed to you as soon as I receive the money.

ORDER ON THE WEB

Tell your WWW browser to go to

http://www.digibuy.com/cgi-bin/order.html?296825+99046733021

and use the online form to register VGBA-Windows. You can pay with a credit card. They take MasterCard, Visa, Amex, or Discover and also allow to register over the phone. The software will be emailed to you as soon as I receive the notification from DigiBuy.

MSDOS

The first (<1.0) versions of VGBA were released for MSDOS. You may find them on the Net for free, but they lack the compatibility and features of the later versions. VGBA-MSDOS has been compiled to run with PMODE/W extender on MSDOS (external extender not required). It will also run on Windows 95/98/ME. I have not tested it on Windows NT/2000, but other people told me that it runs on Windows 2000. The MSDOS distribution includes two flavors of VGBA:

• VGBA8.EXE uses 320x200x8bit screen mode supported by the standard VGA BIOS. It should run on any computer, but is limited to 256 colors. Thus, the colors may sometimes look incorrect.
• VGBA16.EXE uses 320x200x16bit VESA screen mode. Therefore, the VESA drivers are necessary to run this version of VGBA. It will fail on your computer if you do not have VESA drivers that support the 320x200x16bit screen mode.

Unix

I understand that the previous paragraph may sound threatening to some people, but this kind of piracy really hurts my profits and feelings. I've put a lot of effort into VGBA, and can only continue working on it if people do not try to cheat on me.

It may also be a good idea to buy a real cartridge for each GameBoy Advance ROM image you use with the emulator. GameBoy Advance software is copyrighted, but as long as you own the real cartridge, you are protected by the law allowing customers to backup bought software.

• ARM7TDMI CPU with ARM and THUMB opcode sets.
• Internal RAM at addresses 0x03000000 (32kB) and 0x02000000 (256kB).
• Cartridge ROM at address 0x08000000, mirrored at 0x0A000000 and 0x0C000000.
• Cartridge RAM at address 0x0E000000 (64kB).
• Cartridge FlashROM (JEDEC) at address 0x0E000000 (64kB).
• Cartridge serial EEPROM at address 0x09000000 (64x64bits), mirrored at 0x0B000000 and 0x0D000000.
• Interrupts: VBlank, HBlank, line coincidence, timers, DMA, joypad.
• Timers: TIMER0, TIMER1, TIMER2, TIMER3.
• DMA channels: DMA0, DMA1, DMA2, DMA3.
• DMA modes (instantaneous, HBlank, VBlank, HRefresh) and repeat feature.
• Joypad buttons and interrupts.
• GameBoy-compatible melodic sound chip.

• GBA-specific sound hardware is not emulated.
• DMA happens "instantly".
• CPU timings are close but not entirely correct. VGBA considers all memory accesses as "sequential". There are some other discrepancies as well, but overally, it should be pretty close.

GBA BIOS is partly emulated. Including the real Nintendo BIOS with the emulator would be clearly illegal. Therefore, I have tried to simulate GBA BIOS routines by trapping and handling ARM SWI opcodes. Here is the correspondence between BIOS call names and SWI numbers:

The VGBA WWW page contains some links to GameBoy Advance cartridge copier info. Cartridge copiers can be used to dump GameBoy Advance cartridges into files. I cannot provide you with any additional information about these copiers, so do not send me email asking for this information. Use the copier-related links at the VGBA WWW page.

GameBoy Advance has a BIOS ROM inside with some useful subroutines. Including the real Nintendo BIOS with the emulator would be clearly illegal. Therefore, VGBA tries to simulate GBA BIOS routines. It still has an option to use the real BIOS read from the GBA.ROM file in the current directory. I cannot tell you where to find the real BIOS, so do not ask me about it. The BIOS simulation is quite functional and will become better over time.

  [SPACE]    - A button (also: [LALT],A,S,D,F,G,H,J,K,L)
  [LCONTROL] - B button (also: Z,X,C,V,B,N,M)
  [Q]        - LEFT button (also: E,T,U,O)
  [W]        - RIGHT button (also: R,Y,I,P)
  [TAB]      - SELECT button
  [ENTER]    - START button
  [ESC]      - Quit emulation (also: [F12])
  [F1]       - Go into the built-in debugger
  [F2]       - Turn soundtrack logging on/off
  [F3]       - Turn A button autofire on/off
  [F4]       - Turn B button autofire on/off
  [F5]       - Turn LEFT button autofire on/off
  [F6]       - Turn RIGHT button autofire on/off
  [F7]       - Save emulation state to .STA file
  [F8]       - Load emulation state
  [F11]      - Reset GBA hardware
  [F12]      - Quit emulation (also: [ESC])
  [0]        - Turn all sound on/off
  [1]-[4]    - Turn sound channels on/off
  [5]-[8]    - Turn backgrounds display on/off
  [9]        - Turn sprites display on/off

vgba [-option1 [-option2...]] [FILENAME.GBA]

  -uperiod <period>   - Number of interrupts per screen update [1]
  -verbose <level>    - Select debugging messages [1]
                         0 - Silent          1 - Startup messages
                         2 - I/O accesses    4 - Illegal memory accesses
                         8 - DMA transfers  16 - Illegal CPU ops
                        32 - SWI calls      64 - FlashROM/EEEPROM accesses
  -crc/-nocrc         - Check cartridge CRC/CMP [-crc]
  -logsnd <filename>  - Write soundtrack to a MIDI file [LOG.MID]
  -sync <frequency>   - Sync screen updates to <frequency> [-nosync]
                        (<frequency> must be in 20Hz..100Hz range)
  -nosync             - Do not sync screen updates

With #define SOUND:
  -sound [<quality>]  - Sound emulation quality [44100]
                        0 - Off                1 - Adlib (MSDOS)
                        Values >8191 are treated as wave synthesis
                        frequencies. Default frequency is 44kHz.
  -nosound            - Same as '-sound 0'

With #define DEBUG:
  -trap <address>     - Trap execution when PC reaches address [FFFFh]
                        When a keyword 'now' is used in place of the
                        <address>, execution will trap immediately.

With #define MSDOS:
  -vsync              - Sync screen updates to VBlank [-nosync]

With #define UNIX:
  -saver/-nosaver     - Save CPU when inactive [-saver]
  -scale <factor>     - Scale window by <factor> [1]

With #define MITSHM:
  -shm/-noshm         - Use MIT SHM extensions for X [-shm]

1. I WANNA PLAY GAMES!!!! WHERE DO I GET GAMES???????
   I do not know. I can't give you any due to both legal and moral reasons. Please, do not mail me asking for games. I will delete your mail right away, and you won't get an answer.

2. Can I play GameBoy Classic and GameBoy Color games on VGBA?
   No, you can't. GameBoy Advance hardware is completely different from the older GameBoy and GameBoy Color models. To play older games, you may want to consider my other emulator, Virtual GameBoy (VGB) .

3. How do I copy games from cartridges to a computer?
   You can use a special device called cartridge copier, such as Flash Advance Linker from Lik-Sang. Don't forget to get a rewritable flash card too.

4. What is GameBoy Advance? How its hardware works?
   GameBoy Advance (GBA) is a handheld videogame machine made by Nintendo. Its hardware has nothing to do with GameBoy and GameBoy Color handhelds previously produced by Nintendo. GBA is built around an ARM7TDMI 32bit CPU running at 16MHz. GBA video subsystem is very similar to that of SNES, but more advanced. The sound subsystem uses direct sample output. GBA also includes the four-channel melodic sound chip from the original GameBoy.

   In order to be compatible with the original GB/GBC, GBA includes the complete set of GBC hardware. This hardware (aside from the sound chip) is not accessible from the GBA side and only used when somebody inserts a GB/GBC cartridge into GBA.

5. There is no version of VGBA for my Unix!
   I am trying to compile Unix binaries for as many flavors of Unix as possible, but as I do not have access to many machines, do not expect immediate support for every Unix flavor out there. Don't mail me asking for the source either: VGBA source code is not publicly distrbutable, as much as I regret to say this :(.

6. My favorite game doesn't work on VGBA. What do I do?
   There may be several reasons why a game has problems running on VGBA or does not run at all.
   • If emulator does not even recognize the ROM image, its CRC or CMP may be wrong. Try turning CRC checking off by using the -nocrc option or clearing "Check CRC" checkbox in VGBA-Windows Setup Panel. You really need to find an uncorrupted ROM image though.

   • If some sprites blink or do not appear at all, try changing -uperiod value (1 will give you the best picture, but the slowest emulation), or moving an "Update Period" knob in the VGBA-Windows Setup Panel.

   • VGBA may not currently run this game. Not all games are supported at this moment. Don't expect 100% compatibility with the real hardware. At least, not yet :).

7. There is no sound!
   Currently, VGBA only emulates the four channels of the melodic sound that GBA has inherited from the original GameBoy. Unfortunately, most GBA games use the "direct" sample sound that is not emulated in VGBA. I hope to emulate this GBA feature in the later VGBA versions.

8. Why is VGBA so slow on my machine?
   Because your machine is too slow to run VGBA. My experience shows that you need at least a PentiumII/400 machine with fast video to run VGBA at a reasonable speed. Following are the ways to speed things up:
   • Increase Update Period. The picture will get more jerky, but VGBA will become faster.

   • On Unix, always use MIT Shared Memory Extension for X (MITSHM). This, of course, means that you have to run VGB locally.

   • On Unix, run X in 256-color mode.

   • On Windows and Unix, use 1:1 window to achieve the highest speed.

   • On Windows, use MIDI sound, as wave synthesis takes quite a lot of CPU time.

9. VGBA is too fast on my machine! How do I slow it down?
   Frankly, when I started writing VGBA, I never expected that it will be too fast on any machine :). But times change...
   • On Unix, use -sync option to tie screen updates to the certain frequency (usually, 60Hz/UPeriod).

   • On Windows, use "Sync To..." option in the Setup Panel to tie screen updates to a certain frequency (usually, 60Hz divided by UPeriod).

   • Decrease Update Period to 2 or even to 1. The emulation will become much slower, but smoother.

   • On Windows and Unix, double or triple the window size.

10. When starting VGBA-Unix, ld says that some library isn't found.
    This may happen if the versions of your shared libraries are older than the ones for which VGBA has been compiled. A decent way to deal with this is to upgrade your Unix. A quick and dirty way is to make a symbolic link from the existing library to a name required by VGBA.

11. When starting VGBA-Unix, I get X_ShmAttach error.
    You are probably trying to run VGBA-Unix on a remote Xterminal while it attempts to use shared memory for interfacing with X. Use -noshm option to tell it not to use shared memory.

12. When starting VGBA-Unix, I get X_PutImage error.
    VGBA-Unix version currently needs 8bit, 16bit, or 32bit X. Neither 2-color nor 16-color Xterminals will work. 24bit Xterminals may work, but don't count on it.

13. When starting VGBA-Unix, the window stays black.
    Some other X application took over all available colors so that the emulation could not allocate any for itself. Check if you run XV, Netscape, or something similar.

14. The sound is distorted in the VGBA-Windows. How do I fix it?
    The wave-synthetized sound in VGBA may become distorted on slow or highly loaded machines (no graphics acceleration, for example). There are several ways you can improve sound:
    • Use MIDI sound instead. It has both advantages and disadvantages though.

    • Make VGBA window smaller to decrease the load on the CPU. 1:1 is the optimal size.

    • Decrease the sampling frequency (in Setup Panel). The sound may become tinkier, but less distorted.

    • Increase the number of wave buffers (in Setup Panel). This may cause sound to fall a second or two behind the screen action, but the sound quality will become better.

15. Does VGBA-Windows support joystick? My joystick doesn't work!
    VGBA-Windows supports joystick. If your joystick does not work, go into Windows Control Panel to see if it is configured and calibrated properly. Also, some new joysticks working in esoteric standards (like GRiP) are known to have problems.

16. VGBA-Windows starts, but then quits immediately!
    Check the pathname to wherever your VGBA is located. It should not contain spaces. For example, "C:\Program Files\VGBA" is a bad place for VGBA, while "C:\VGBA" will work. This bug is caused by an old version of C compiler I am using. I hope to get rid of it when I switch to a new compiler.

17. Colors are all screwed up in VGBA-Windows!
    VGBA-Windows requires Windows to be in 65536-color or better color mode. When running Windows in 256-color mode, it will try to approximate colors to existing ones, but expect results to be dismal.

18. Black window in VGBA-Windows!
    If you are running Windows in 256-color mode, then this is most likely the cause of a problem. Try switching Windows into 65536-color or better screen mode.

19. Command line options don't work in VGBA-Windows!
    They shouldn't. The demo version of VGBA-Windows supports no command line interface at all. The full version will only accept the .GBA file name at the command line, but no options. All configuration is done via Setup Panel and VGBA.INI file.

20. Volume control works strangely in VGBA-Windows!
    It is a result of the volume control being shared between VGBA and other Windows applications. You can usually restore normal volume by leaving VGBA window and then activating it again.

21. How do I save and load the GBA state during the game?
    The GBA state can be saved by pressing [F7] button. The resulting data file will have the same name as your .GBA file, but its extension is going to be .STA. You can load state from this file by pressing [F8] at any point in the game. This state file will also be loaded automatically next time you start VGBA. The same state file is not guaranteed to work for versions of VGBA running on a different hardware. State saving is not perfect yet, so for some games state may not be correctly saved.

• Prior to running the program, VGBA will check CMP and CRC of the ROM image. If they do not match CMP/CRC given in the cartridge header, VGBA will refuse to run the program. To make your program run, either fix CMP/CRC (preferable) or use the -nocrc option. Also, be aware that Nintendo requires CRC of a cartridge to be 0 i.e. your ROM image must have padding bytes somewhere that compensate CRC to be zero.
• Many demos use random areas of address space for RAM. Apparently, GBAEmu will create RAM at any address accessed by the program. The real GBA (according to the latest specification) is only going to have RAM at addresses 0x03000000 (32kB) and 0x02000000 (256kB). Use only this memory.
• Many demos use cartridge address space (0x08000000 and up) as RAM. This is not correct as cartridge ROM is not writable. Please, use RAM areas described above.
• In graphical screen modes (MODEs 3,4,5) the entire screen is treated as background #2. This means that to actually show the screen you have to enable background #2 in DISPCONT and set appropriate bits in BG2CONT.
• The backgrounds are shown in the order 0,1,2,3, with background #0 being on top and background #3 on the bottom. When you set different background priorities, the backgrounds with lower priorities will be on top.
• When using ARM data comparison opcodes, you should always set the S flag in the opcode. In fact, ARM7TDMI programming manual explicitely requires this.
• At least two demos (FireDemo and ConsoleDev Demo) are using reads from non-aligned addresses. While non-aligned reads are a documented feature of ARM7TDMI CPU, they are rarely used and cannot be efficiently simulated. The current VGBA binary has been compiled to be compatible with these demos. In the next version, I hope to use fast read functions that speed up emulation but do not simulate non-aligned reads.
• Older (pre-TS2) development boards from Nintendo had hardware different from the later boards (TS2 and up). VGBA will not correctly run some programs compiled for TS1, such as programs using interrupts.