68030 CPU Board REV7 Jumper Settings

Jumper  Default    Description
J1      Shorted    Reserved for future use
J2      OPEN       Reserved for future use
J4      OPEN       Connects 68882 FPU to oscillator US when shorted
J5      SHORTED    Connects 68882 FPU to oscillator U1 when shorted
J6      OPEN       Disables 68030 MMU when shorted
J7      ---->>     OPEN for 50MHz clock speed and SHORTED for lower
                   clock speeds
J9      SHORTED    Remove this jumper to enable the 68030 Boot code EPROMS
                   (U23 and U25) when these are installed
J10     SHORTED    A2000 Motherboard type. Shorted for A2000 motherboards
                   REV4.0 and up (type B2000) Open for original 4-layer
                   German motherboard. When this jumper is left open the
                   68000 CPU must be removed.
J11     OPEN       Disables 68030 CPU and bootup in 68000 mode when shorted
J12     OPEN       SHORT to change clocking mode for compatibility with old
                   German A2000 motherboard
J13     OPEN       SHORT to change clocking mode for compatibility with old
                   German A2000 motherboard
J14     SHORTED    OPEN to change clocking mode for compatibility with old
                   German A2000 motherboard
J15     SHORTED    OPEN to DISABLE the code contained in the Autoboot
                   EPROM (U34)
J16     SHORTED    Reserved for diagnostic use
J17     SHORTED    Set size of EPROM being used for "AT" Autoboot EPROM (U34)
                   SHORTED for 27256 type and OPEN for 27128 type
J18     SHORTED    OPEN when an "AT" hard drive is connected to enable the
                   "AT" driver code in the Autoboot EPROM (U34). This jumper
                   is only relevant when using Autoboot EPROM v3 or later.
NOTE: J10, J12, J13 and J14 are a set and must be changed over at the same
      time when installing into an A2000 with an old 4-layer German board.
      68000 CPU must also be removed at the same time.

Jumper  Default    Description
J1      SHORTED    Refresh rate
J2      OPEN       Refresh rate
J3      ---->>     Refresh rate, OPEN for 50MHz, Shorted for lower clock.
J4      SHORTED    Refresh rate
J11     OPEN       Refresh rate
J8      SHORTED    Refresh enable
J6      SHORTED    Reserved
CN11    ---->>     All pins OPEN for 50MHz clock speed. SHORT pins 2 and 3
                   for lower clock speeds. Pin 1 indicated by arrowhead.
CN12    SHORT1-2   SHORT pins 1 and 2. Pein 1 indicated by arrowhead.
CN13    ---->>     SHORT for 50MHz clock speed OPEN for lower.
J5      ---->>     SHORTED when using only (up to 8) 1MB SIMMs. NOTE that
                   this is the only option supported for speeds below 50MHz
50MHz clock speed option only: OPEN when using FOUR 1 MB SIMMs in sockets
CN3-CN6 and up to FOUR 4 MB SIMMs in sockets CN7-CN10. Allows a maximum of
20MB 32-bit wide RAM.

RAM SIZE  RAM Type     Qty   RAM Location      Jumper J5
2         SIMM32-1MB     2   CN3-CN4           On
4         SIMM32-1MB     4   CN3-CN6           On
8         SIMM32-1MB     8   CN3-CN10          On
8*        SIMM32-1MB     4   CN3-CN6           Off
          SIMM32-4MB     1   CN7               Off
12*       SIMM32-1MB     4   CN3-CN6           Off
          SIMM32-4MB     2   CN7-CN8           Off
16*       SIMM32-1MB     4   CN3-CN6           Off
          SIMM32-4MB     3   CN7-CN9           Off
20*       SIMM32-1MB     4   CN3-CN6           Off
          SIMM32-4MB     4   CN7-CN10          Off
* Note: These RAM settings require the use of the SIMM32-4MB which only
fuction in the 50MHz version of the '030 accelerator. It also requires
that jumper J5 be open.