pinout, numbered according to the silkscreen markings
on the controller's PCB:

  Pin   Name      Note
-----------------------
  1     Ground
  2     A14       (1)
  3     A12
  4     A7
  5     A6
  6     A5
  7     A4
  8     A3
  9     A2
  10    A1
  11    A0
  12    D0
  13    D1
  14    Detect    (2)
  15    3.3v
  16    D2

  17    Ground
  18    Unknown 1 (3)
  19    A15
  20    /WE
  21    A13
  22    A8
  23    A9
  24    A11
  25    /OE
  26    A10
  27    D7
  28    D6
  29    D5
  30    D4
  31    3.3v
  32    D3

Note 1:
   With 15 address lines, that gives standard memory paks a 32k capacity.
   The Nyko Hyperpak tested has 128k of SRAM, but includes a switch that
   selects between four 32k banks.

Note 2:
   There's a 3k resistor between detect and +3.3v in the controller pak.
   When this signal is high, the controller thinks a controller pak is
   present- it will attempt to read and write from it, and it acknowledges
   to the N64 with an 0xE1. When this signal is low, the controller doesn't
   attempt any writes or reads and it acknowledges with 0x1E.

Note 3:
   Possibly a chip select