Some info from James W. Birdsall's reference document;
501-1638        motherboard 16M FCC-A (4/75 (SPARCstation 2))
....
MEM LAYOUT: 
      Memory consists of up to sixteen 4M (501-1739) x 9 80ns
      30-pin SIMMs, in four banks. Each bank consists of one
      slot in each group of four. The SIMM slots form two
      columns in the far half of the board.

      THERE IS SOME DISPUTE OVER WHICH SLOTS BELONG TO WHICH
      BANKS, or alternatively what order to fill them. The Sun
      Field Engineer Handbook for 12/15/93 says that the banks
      are in order as shown above but doesn't give a fill
      order. Other sources agree that banks are in order 0, 2,
      1, 3, and should be filled in numerical order, which is
      interestingly equivalent to a *fill* order of 0, 2, 1, 3
      with the banks in numerical order as shown -- and that
      was the fill order of near relatives (the SPARCstation 1
      and 1+).

              Nearest disk connectors

                               bank
          byte  ----U0317---- 3    3 ----U0318---- byte
              2 ----U0315---- 2    2 ----U0314----     1
          bits  ----U0308---- 1    1 ----U0310---- bits
           8-15 ----U0307---- 0    0 ----U0309----  16-23

          byte  ----U0316---- 3    3 ----U0319---- byte
              3 ----U0320---- 2    2 ----U0313----     0
          bits  ----U0321---- 1    1 ----U0312---- bits
            0-7 ----U0322---- 0    0 ----U0311----  24-31

              Nearest SBus connectors


------------------------------------------------------------
Rex McMaster                            rmcm@compsoft.com.au 
                                   rex@mcmaster.wattle.id.au
     PGP Public key: http://www.compsoft.com.au/~rmcm/pgp-pk