Cartridge connector

Pinout

This diagram represents a top-down view looking directly into the connector. Pins 01-31 are the bottom side of the connector and label side of the cartridge.

           SNES  | Cart  |  SNES
         (front)  -------  (back)
   SYSTEM CLK <- |01   32| -> /WRAMSEL
       EXPAND <> |02   33| -> REFRESH
          PA6 <- |03   34| -> PA7
        /PRD <- |04   35| -> /PWR

          GND -- |05   36| -- GND
          A11 <- |06   37| -> A12
          A10 <- |07   38| -> A13
           A9 <- |08   39| -> A14
           A8 <- |09   40| -> A15
           A7 <- |10   41| -> A16
           A6 <- |11   42| -> A17
           A5 <- |12   43| -> A18
           A4 <- |13   44| -> A19
           A3 <- |14   45| -> A20
           A2 <- |15   46| -> A21
           A1 <- |16   47| -> A22
           A0 <- |17   48| -> A23
         /IRQ -> |18   49| -> /ROMSEL
           D0 <> |19   50| <> D4
           D1 <> |20   51| <> D5
           D2 <> |21   52| <> D6
           D3 <> |22   53| <> D7
          /RD <- |23   54| -> /WR
   CIC data 1 <> |24   55| <> CIC data 2
key CIC reset <- |25   56| <- CIC CLK
       /reset <> |26   57| -> PHI2
          +5V -- |27   58| -- +5V

          PA0 <- |28   59| -> PA1
          PA2 <- |29   60| -> PA3
          PA4 <- |30   61| -> PA5
left audio in -> |31   62| <- right audio in
                  -------

Signal descriptions

• EXPAND: Connects to expansion port pin 24 and is pulled high.
• SYSTEM CLK: 21.47727 MHz system clock.
• PHI2: This is the CPU clock output. When this signal is high, this means only that the CPU bus address is in a stable state. For both reads and writes, data is only guaranteed or required to be valid at the falling edge of this signal. /RD, /WR, /PRD, and /PWR are normally used instead of this.
• A23..0, /RD, /RW: The CPU address bus, also known as the A bus.
• A23..16: Also known as bank address or BA7..0.
• /ROMSEL: Asserted when accessing ROM ($00-3F,80-BF:8000-FFFF, $40-7D,C0-FF:0000-FFFF). Also known as /CART.
• /WRAMSEL: Asserted when accessing work RAM ($00-3F,80-BF:0000-1FFF, $7E-7F:0000-FFFF).
• PA7..0, /PRD, /PWR: The peripheral address bus, also known as the B bus.
• D7..0: Data lines, shared between the CPU and peripheral buses.
• CIC CLK: Either 4 MHz or 3.072 MHz, depending on the console.