MMC3 pinout

    33   23
    |    |
   .------.
34-|      |-22
   | MMC3 |
44-|      |-12
   \------'
    |    |
    01   11

Pin	Function	Pin	Function	Pin	Function	Pin	Function
01	??? *1	12	CHR A17	23	PRG A18	34	CPU D0
02	CHR A10 *1	13	/IRQ	24	CPU A13	35	CPU D5
03	PPU A12	14	CPU /CE	25	PRG A17	36	CPU D1
04	PPU A11	15	GND *2	26	PRG /CE	37	CPU D4
05	PPU A10	16	??? *2	27	VCC	38	CPU D2
06	GND	17	CPU R/W	28	GND	39	CPU D3
07	CHR A13	18	PRG A15	29	M2	40	GND
08	CHR A14	19	PRG A13	30	PRG RAM /CE	41	PRG RAM +CE
09	CHR A12	20	CPU A14	31	CPU D7	42	PRG RAM /WE
10	VRAM A10	21	PRG A16	32	CPU A0	43	CHR A11
11	CHR A15	22	PRG A14	33	CPU D6	44	CHR A16

• 1: PINS 1 & 2. Sometimes these are connected together. If they are not, pin 1 is left floating.
• 2: PINS 15 & 16. Sometimes these are connected together. If they are not, pin 16 is left floating.