Game Pak

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

Pinout

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

Note: Direction is cartridge relative Game Boy.

Game Pak GBA SRAM

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.

Compatibility

Size

Contributions

• Joakim Ögren

Sources

• GBATEK: Gameboy Advance Technical Info
• Nintendo Game Boy: Compatibility Chart