drhelius

Memory Bank Controller (MBC) 3 for GameBoy Information



            by bRILLO hEAD, 1-Jan-98



 The MBC3 is a memory controller for some GameBoy carts

drhelius

Nitty Gritty Gameboy Cycle Timing
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A document about the down and dirty timing of the Gameboy's video hardware.

Written by:  Kevin Horton
Version: 0.01 (preliminary)

My findings here are based on the original DMG, Super Gameboy, and GB

drhelius

Game Boy Sound Operation
------------------------
Shay Green (blargg)
gblargg@gmail.com
http://www.slack.net/~ant/

** This is an incomplete draft

This documents the behavior of Game Boy sound; details which aren't
relevant to the observable behavior have been omitted unless they

drhelius

To detect Super Game Boy, the values of SGB Flag and Old Licensee Code must be set in the cartridge header. In detail, that would mean that the value of $0146 is $03 and the value of $014B is $33.

To detect Game Boy Color, use the value of the CGB Flag in the cartridge header. If the value of $0143 is $80, then the game should be compatible with both normal and color Game Boy models. If it is $C0, then it should only work with Game Boy Color.

Additionally, some games check the value of the Accumulator directly after startup. If the value is $01, then the hardware is either Super Game Boy or normal Game Boy. If it is $FF, then the hardware is either Super Game Boy 2 or Game Boy Pocket. If it is $11, then it is either Game Boy Color or Game Boy Advance.

Lastly, you can detect if the game is on a Game Boy Advance by checking bit 0 of the B register directly after startup. If it is cleared, it is a Game Boy Color. If it is set, it is a Game Boy Advance.
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Note: The Super Game Boy 2 was little more th

drhelius

GameBoy Color DMA-Transfers v0.0.1                           13.04.2000/GPZ-HIT
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"old" DMA Transfer (aka 'OAM-DMA')
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source:      - anywhere from $0000 to $dfff
             - must be page-aligned
destination: - always OAM-Ram at $fe00 - $fe8f
length:      - always 4*40 (=160 / $a0) bytes