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Jumpers
~~~~~~~
The A3000D main board has many jumpers which configure the system.

             16MHz PAL       25 MHz PAL
                     16 MHz NTSC     25 MHz NTSC
               313311  313311  313311  313311
Jumper  Pins    -01     -02     -03     -04     Function
_____________________________________________________________________________
J100    4       2-3     2-3     1-2     1-2     Quadrature Clock Phasing
J101    3       2-3     2-3     2-3     2-3     FPU Clock Source
J102    3       2-3     2-3     2-3     2-3     System Clock Source
J103    4       3-4     3-4     3-4     3-4     FPU CS/BERR
J104    3       1-2     1-2     1-2     1-2     CPU Clock Source
J200    3       1-2     2-3     1-2     2-3     NTSC/PAL Select
J151    3       2-3     2-3     1-2     1-2     ROM Timing
J152    3       2-3     2-3     1-2     1-2     ROM Timing
J180    3       2-3     2-3     2-3     2-3     A2000 ROM Compatibility jmpr.
J181    3       2-3     2-3     2-3     2-3     A2000 ROM Compatibility jmpr.
J350    3       1-2     1-2     1-2     1-2     Tick Clock Source
J351    3       2-3     2-3     2-3     2-3     Disable DF1: (1-2 enable)
J352    3       2-3     2-3     2-3     2-3     Light Pen Source
J481    3       2-3     2-3     2-3     2-3     VDE Scan Doubler only jmpr.
J482    3       1-2     1-2     1-2     1-2     VDE PLL Loop Adjust.
J483    3        -       -       -       -      VDE Factory test points.
J800    3       1-2     1-2     1-2     1-2     WD33C93 Speed
J851    3       1-2     1-2     2-3     2-3     RAM Controller speed jmpr.
J852    5       4-5     4-5     4-5     4-5     -012A Ramsey only (see notes)
J853    3       2-3     2-3     2-3     2-3     -012A Ramsey only (see notes)

*Notes:*
  J150, J151:   ROM Timing
        The Rom timing circuit provides four different speed settings to
        match the output enable and access timing of the system ROMs.

        To set the jumpers, determine the output enable time and access times
        for the ROMs you wish to use. The ROM must have lower value than for
        the setting you select.

        System standard ROMs have T(oe)=110ns, and T(acc)=250ns.

        CLK     J151    J150    T(oe)min        T(acc)min
        16 MHz  2-3     2-3     157ns           250ns
        16      2-3     1-2     220             312
        16      1-2     2-3     282             375
        16      1-2     1-2     345             437

        25 MHz  2-3     2-3     90ns            160ns
        25      2-3     1-2     130             200
        25      1-2     2-3     170             240
        25      1-2     1-2     210             280

   J180, J181:  ROM Compatibility jumpers
                                J180    J181
        A2000/A500 ROMs         1-2     1-2
        A3000 ROMs              2-3     2-3

   J851-J853    RAM Controller compatibility settings
                                        J852    J853
        -012 Ramsey w/256Kx4 RAMs       4-5     2-3
        Later Ramseys w/256Kx4RAMs      2-3     1-2
        Later Ramseys w/1Mx4 RAMs       1-2     1-2

See also, ROM Timing Issues


NVRAM
~~~~~
The A3000 also has a NVRAM configuration which is powered by the
same battery which the clock is.  It supports the setup of the following:

SCSI Controller ID:This places the onboard SCSI controller
at a specific ID location, 7 by default.
You can change this to something else,
to get a device at 7, but be careful
of conflicting the SCSI controller and the
device addresses.

Long SCSI Timeout:This slows the boot process for SCSI
drives, for those units which take longer
to spin up and be ready. 

Synchronous SCSI:This enables Synchronous SCSI mode,
which can speed access on some drives.
This is fully operational on Kickstart 3.1.

Multiple LUNs Mode:This enables multiple LUN's, which allows
for multiple drives at each address.

These options can be toggled using various freeware programs
available on the Aminet file archive on the Internet.  SCSIPrefs
(Aminet:hard/drivr/SCSIPrefs.lha) is one of them, but there are many
others.  Some things to note: It's a better idea to get a Prefs program
that is simple, basic and doesn't use any OS extensions like MUI, as if
you accidentally set something wrong and your system doesn't boot, it'll
be easier to load your basic Prefs program than something which requires
all of MUI.  Why do I write this?  A friend did this and had to install a
base MUI setup, taking many extra hours.


A3000T CPU JUMPERS
~~~~~~~~~~~~~~~~~~
     Without U103 (74F08) fitted     |        With U103 (74F08) fitted
                                     |
A3000T (normal030)    A3000T (A3640) |  A3000T(3640-74F08) A3000T(030-74F08)
_____________________________________|______________________________________
J100  1-2 (closed)    3-4 (removed)  |  3-4 (removed)      1-2 (closed)
J102  2-3 (closed)    2-3 (closed)   |  2-3 (closed)       2-3 (closed)
J104  1-2 (closed)    2-3 (removed)  |  2-3 (removed)      1-2 (closed)
J105  2-3 (removed)   2-3 (removed)  |  1-2 (closed)       1-2 (closed)
J106  2-3 (removed)   2-3 (removed)  |  1-2 (closed)       1-2 (closed)
J107  2-3 (removed)   2-3 (removed)  |  1-2 (closed)       1-2 (closed)

74F08 is normaly NOT there in A3000T...these settings don`t work without it!
There should be an empty socket (U103) on the board for it.  These jumper
settings disable the 74F244 (U105) which does not work well with '040's
and enable U103 which will work with a 3640.

Note:- That pin 4 on J100, and pin 3 on J104, J105, J106, and J107 are dead
       pins, so the jumpers can be moved there rather than removed.  Leave
       J103 set to 3-4.

For a 3000/25 Desktop, the settings are the same except for J105,106 and 107
which do not exist since the 74F08 is already there.

For a 3000/16 Desktop, ditto except that J100 in normally 2-3 and in addition
J151 and J152 change from 2-3 to 1-2 and J851 changes from 1-2 to 2-3.  That
will adjust the ROM and RAM timing to 25 MHz as well.

Also, get SCSIprefs and check your Battmem settings, it may be wise to turn
sync mode off if necessary, until you have everything working.

If you have 2.x ROMs, static column RAM, and old DMAC/Ramsey you will have
to replace the first chip in bank-0 with a page mode.

If you have 3.1 roms and page mode ram, add the "NOCACHE" option to the
SetPatch command, then add a "CPU CACHE" command after it to turn them back
on again.

Insure that you have the 68040.library installed in libs: (preferably the
latest version).


Information by Dale Currie, copied from comp.sys.amiga.hardware