Wonderswan Cartridge Pinout

Building Wonderswan Cart Using SRAM

The following document contains notes on how to build a Wonderswan cartridge whose information is stored on SRAM. Using this, you should be able to come up with a 64 kilobyte cartridge, which is the maximum you can use without reverse engineering Bandai's bank switching code on their proprietary chip.

The rightmost pin with the label facing up is pin 0, the leftmost is pin 47. The cartridge runs on 3.3V. When plugged into the Wonderswan, the cartridge is powered by 3.3V coming in pins 23 and 24. In order to run your custom cartridge with just memory chips, you'll need to bypass the handshake. IIRC, grab a real cartridge, plug it in, push start+power. This will boot into the Wonderswan BIOS where you can enter name and stuff. Go all the way to the bottom, but don't hit okay just yet. Remove the real cartridge and put in your own and then press OK. Make sure both cartridges have the same orientation (sideways or normal eg: space invaders or final fantasy).

The pins on the edge connector are only on one side, and their pitch is 1.25 mm (NOT 1.27 mm, which is a more common pitch). I do not know of any place that sells edge connectors like that. Your best bet is to etch your own board.

	Pin No.	Connected to
	0,47	GND
	9	D13(HI SRAM D5)
	10	D12(HI SRAM D4)
	11	D11(HI SRAM D3)
	12	D10(HI SRAM D2)
	13	D9(HI SRAM D1)
	14	D8(HI SRAM D0)
	19	A2(BOTH SRAM)
	20	A1(BOTH SRAM)
	21	A0(BOTH SRAM)
	23	VCC
	24	VCC
	25	D0(LO SRAM D0)
	26	D1(LO SRAM D1)
	27	D2(LO SRAM D2)
	28	D3(LO SRAM D3)
	29	D4(LO SRAM D4)
	30	D5(LO SRAM D5)
	31	D6(LO SRAM D6)
	32	D7(LO SRAM D7)
	33	D14(HI SRAM D6)
	34	D15(HI SRAM D7)
	35	A3(BOTH SRAM)
	36	A4(BOTH SRAM)
	37	A5(BOTH SRAM)
	38	A6(BOTH SRAM)
	39	A11(BOTH SRAM)
	40	A13(BOTH SRAM)
	41	A12(BOTH SRAM)
	42	A7(BOTH SRAM)
	43	A8(BOTH SRAM)
	44	A10(BOTH SRAM)
	45	A9(BOTH SRAM)
	46	A14(BOTH SRAM)