Game Pak

From HwB

Available in Nintendo GB, GBC, GBA, GBA SP, GBM, DS & DS Lite.



32pin cartridge slot. The cartridge bus may be used for both CGB and GBA game paks. In GBA mode, it is used as follows:

Pin Name Dir Description
1 VDD35 Arrowl.png Power Supply (3.3VDC/5VDC)
2 PHI Arrowl.png System Clock (selectable none, 4.19MHz, 8.38MHz, 16.78MHz)
3 /WR Arrowl.png Write Select
4 /RD Arrowl.png Read Select
5 /CS Arrowl.png ROM Chip Select
6-21 AD0-15 Arrowlr.png lower 16bit Address and/or 16bit ROM-data (see below)
22-29 A16-23 Arrowlr.png upper 8bit ROM-Address or 8bit SRAM-data (see below)
30 /CS2 Arrowl.png SRAM Chip Select
31 /REQ Arrowr.png Interrupt request (/IREQ) or DMA request (/DREQ)
32 GND Arrow.png Ground 0V

Note: Direction is cartridge relative Game Boy.


A 16bit address is output through AD0-AD15, then 8bit of data are transferred through A16-A23.

Game Pak GBA ROM

24bit address is output through AD0-AD15 and A16-A23, then 16bit of data are transferred through AD0-AD15. The 24bit address is formed from the actual 25bit memory address (byte-steps), divided by two (halfword-steps).

Game Pak 8-bit

In 8-bit mode 5V is used. GBA & GBA SP have a mechanical switch which the card pushes to select between 3V or 5V.

In 8bit mode, the cartridge bus works much like for GBA SRAM, however, the 8bit /CS signal is expected at Pin 5, while GBA SRAM /CS2 at Pin 30 is interpreted as /RESET signal by the 8bit MBC chip (if any). In practice, this appears to result in 00h being received as data when attempting to read-out 8bit cartridges from inside of GBA mode.


Game Pak type
Original Dual Mode Game Boy Color Only Game Boy Advance Only
Game Boy OK OK - -
Game Boy Pocket OK OK - -
Game Boy Color OK OK OK -
Game Boy Advance / Game Boy Advance SP OK OK OK OK
Nintendo GameCube Game Boy Player OK OK OK OK
Game Boy Micro - - - OK
Nintendo DS / Nintendo DS Lite - - - OK


Original Dual Mode Game Boy Color Only Game Boy Advance Only
Grey Black Clear
Size 5.8 x 6.5 cm  ? x ? cm
Voltage level 5VDC 3VDC