S1000 & S1100 memory board positions and jumper/switch settings

Robin Whittle 20 September 2000

Back to my Akai 32 Meg memory board page.

I wrote this in reply to an enquiry on the Akai Sampler Discussion List:


Someone wrote:

> I finally found an extra 8 Mb memory board for my old S1000-KB.
> Now there´s only one problem: I´m a complete technical idiot.
> Where should I put the darn thing?

Since you are a "technical idiot", please be a wise one and give your
sampler, the memory board and these instructions to a technician, rather
than risk your life and the integrity of the sampler by opening it up
yourself!  In the meantime, keep the memory board wrapped in aluminium

I used to make 8 Meg cards for the S1000/S1100.  Check my page:


for details of my cost-effective 32 Meg cards for these samplers and for
the S2800/S3000/S3200/CD3000 machines as well.

For both the S1000 and S1100 (the S1000-KB would be identical to the
S1000) there are two issues regarding memory board installation:

1 - Placement of the boards in the correct slots.

2 - Setting jumpers (S1000) or switches (S1100) on the motherboard
    to make the machine accept 8 Meg cards in addition to or
    instead of 2 Meg cards.

This information is adapted from the documentation I provided with my 8
Meg cards - which was based on Akai instructions, the instructions which
came with other memory boards and my experience.  I believe it to be

Before giving those details, two notes:

1 - The Akai and other brands of 2 or 8 meg cards are rather
    dodgy in the S1000 and S1100 since the motherboard's signals,
    when applied to those cards, violate the timing requirements of
    the RAM chips on the cards.  So if the chips did not work properly
    it would not be surprising.  A description of the problems
    would only make sense to someone who understands DRAM timing

    Consequently, Akai and other memory boards do not always work
    correctly - particularly when the sampler gets hot.  (Some people's
    samplers get *extremely* hot because they are in racks with no
    ventilation or other way of dissipating heat.)

    I redesigned my 8 Meg boards to overcome this timing problem.  Still
    there are many other challenges to a designer of such boards,
    such as the Address/Data bus on the S1100 having a bunch of
    capacitors on the motherboard (an Akai fudge to reduce the
    timing problem just mentioned) which can cause severe ground bounce
    in the memory board when it reads data from RAM onto the bus.

    My 32 Meg boards completely overcome the timing, ground bounce and
    all other problems I am aware of.

2 - My 32 Meg boards behave like four 8 Meg boards, and it does not
    matter what the motherboard jumper/switch settings are.  These
    boards typically dissipate less heat than four 2 or 8 meg boards.

Now to the jumpers, switches and board arrangements.  This information
is believed to be good - but it is your responsibility what you do with
your sampler.  This information is sufficient to assist an experienced
technician - it is *not* intended to encourage people who don't know
what they are doing work on a dangerous (mains voltage) and delicate
(for many reasons, including static electricity) machine like an Akai
sampler.   *Do Not* request further information to help you!  Everything
you need is here - and if you don't understand it, get a technician who
does understand it to do the work!

S1000 Jumpers

The machine, by default, is configured for 2 Meg boards only.  To make
it work with one or more 8 Meg boards, you have to cut two tracks on the
*underneath* of the motherboard, and install two wires there or on the
front side.  This means you have to lift the entire motherboard out of
the machine.  This is hard work, since even with all the cables
disconnected, it is a squeeze.  Note very carefully exactly where the
cables go.  I seem to remember one of them is labelled on the PCB
differently from the way it is actually connected.

(I am describing this from memory and by looking at a rear-view PCB
layout in the service manual.  The diagrams below will look like garbage
if you view this with a proportional spaced font, so be sure to select
Courier or some other fixed width font instead.)

Near pin 1 and 20 of IC31 are 8 pads in two rows of 4.  Normally, there
are two tracks connecting two pairs of pads - on the underside of the
PCB.  You need to cut those two tracks and install two small jumper
wires to wire up the other two pairs of pads.

Initially, looking from underneath the PCB, with the rear to your left
and the left of the PCB to the top, you have:

    O--O  O--O
       |     |
    O  O  O  O

Cut those track and wire it up so that it becomes:

    O--O  O--O
    |     |
    O  O  O  O

Normally, W12 and W13 drive D0 (pin 1) and D1 (pin 2) of IC32.  The
changes make W14 and W15 drive these pins instead.

S1100 DIP Switch settings

If you are using one or more 8 Megabyte boards, then you must set some
switches on the motherboard - switches 1 & 2 ON and switches 3 & 4 OFF.
If you ever return to using purely 2 Megabyte boards, then set the
switches back to the factory standard - switches 1 & 2 OFF and switches
3 & 4 ON.

Board arrangements for S1000/S1100

Here are what I understand are the the allowable combinations - which
include some combinations not documented by Akai.  The four memory
"slots" are connectors at the rear right of the motherboard.  They are
numbered right to left, 0 to 3.  (Note the S1100 has another connector,
labelled for the DSP board - which is a big board with a Motorola
DSP56000 chip on it.  This is not a memory board "slot".)

The allowable combinations of purely 8 Meg boards are:

  Slot 3   Slot 2   Slot 1   Slot 0


                         8        8

                8        8        8

       8        8        8        8

I assume the same pattern should be followed if you are using only 2 Meg
boards - but make sure the jumper/switch settings are for 2 Megs.

If you are using one or more 8 Meg boards, set the jumper/switches as
noted above.  The allowable combinations of mixed 8 and 2 Meg boards

  Slot 3   Slot 2   Slot 1   Slot 0


                         8        2

                8        8        2

       2        8        8        2

The only combination not mentioned here is three 8 Meg and one 2 Meg.
You can experiment with that, since there are only four possible
arrangements, but I would guess that 8, 8, 8, 2 would be the best.

 - Robin

Back to my Akai 32 Meg memory board page.