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  Expanding memory: Mephisto Montreux and Risc 2500
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   Author  Topic: Expanding memory: Mephisto Montreux and Risc 2500  (Read 3808 times)
Larryh71
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« on: June 6, 2010, 06:32AM »
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Quote from: TurboKing on December 12, 2007, 05:16PM   

Hello

I have a RISC 2500 but already upgraded
I thought  that only inserting the four sticks was all what one needed to upgrade it .
I did not know that upgrading also required setting the jumpers correctly.

Anyway , owing to your thread , I was able to upgrade my Saitek Turbo King

When released , TK I had no endgame ROM next to the game ROM  and you needed to buy this endgame ROM and insert it , but it did not say to set the jumper correctly !
How to insert it was the only explanation , so I thought that it was upgraded since 92 when I bought the endgame ROM..How stupid I am
Indeed ,  after reading what was written on the ROMs a few days ago , I noticed a jumper close to the endgame ROM on the back of the computer.
I set the jumper on position 2-3 instead of 1-2 and this was finally upgraded
However , please confirm that upgrading also required setting the jumper correctly because I read nowhere that you need to change the position of a jumper.
Thank you for your useful thread

Cheers

Hi TurboKing, when you found out that you had finally
upgraded your TK, did you notice much difference in
performance? My TK is a '1', although I do have an
endgame rom1 to put in it, which gives perfect play for
K+P vs K and K+p vs K +p, provided the pawns are
blocked. An engame rom2 will be hard to come by.
all the best..
Larry
« Last Edit: June 6, 2010, 06:35AM by Larryh71 » Report to moderator Logged

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Sargon
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #1 on: May 11, 2009, 10:50AM »
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Hello,

I have tryed to upgrade mine Montreux to 2MB but he will not allow that
some reason he jams ,all the things wich has to be done where done,but no result.

But indeed what Robert did say from 512kb to 2MB brings not very much,from 128kb to 2MB brings +- 35 elo

Kind Regards,Hans
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hawk
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #2 on: May 5, 2009, 12:50PM »
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Hello
I just tried to upgrade my RISC 2500 to 2MB based on the info in this thread.
Unfortunately my unit looks differently inside. First of all it has the look like the picture on the Montreaux circuit board. Secondly stickers on power adapter and unit says it is modified to raise the voltage from 5.4 to 5.6V. This suggests that it actually is a Montreux inside less the Montreux EPROM?
My unit is a late one, from December 1995, when the Montreux had been in production for a while - perhaps Saitek used the Montreux board on the last batch of RISC 2500 for production reasons?
There is however a further difference on my unit: on one of the SRAM chips, the /WE pin (Write Enable) is connected to the GND pin via an external pull-down resistor placed on top of the chip (180ohm).
So - I tried, without success, to replace the SRAM chips, added the pull-down resistor and changed the Jumpers.
When I press ON, the boot process starts by lighting LED 8 & 7 + the LEDs A-H flashes a 'marching ants' sequence repeatedly -and nothing more happens. What LED lighting should I expect on a 2MB unit? Anyone having experiences with a RISC 2500 animal like mine?
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TurboKing
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #3 on: December 12, 2007, 05:16PM »
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Hello

I have a RISC 2500 but already upgraded
I thought  that only inserting the four sticks was all what one needed to upgrade it .
I did not know that upgrading also required setting the jumpers correctly.

Anyway , owing to your thread , I was able to upgrade my Saitek Turbo King

When released , TK I had no endgame ROM next to the game ROM  and you needed to buy this endgame ROM and insert it , but it did not say to set the jumper correctly !
How to insert it was the only explanation , so I thought that it was upgraded since 92 when I bought the endgame ROM..How stupid I am
Indeed ,  after reading what was written on the ROMs a few days ago , I noticed a jumper close to the endgame ROM on the back of the computer.
I set the jumper on position 2-3 instead of 1-2 and this was finally upgraded
However , please confirm that upgrading also required setting the jumper correctly because I read nowhere that you need to change the position of a jumper.
Thank you for your useful thread

Cheers
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Robert Weck
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #4 on: December 10, 2007, 11:51PM »
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Here is a good picture of a jumper in the German wikipedia:
http://de.wikipedia.org/wiki/Jumper


Robert
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Meca
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #5 on: December 10, 2007, 04:43PM »
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Quote from: Larry71 on December  9, 2007, 04:53PM   

By the way, why did you remove the ARM
processor?


Hello, Larry, the ARM is in different sides of the electronic boards, that is the reason you see it in the "Risc" photos and you can't see it in the "Montreux" Photos.

This is the MONTREUX board



and this is the RISC 2500 board



One has de ARM above and the other has it below.



About jumpers, very easy, with the standard connector, in a 3 pin jumper only is possible 3 positions, 1) no connector 2) join 1-2 pin 3) join 2-3 pin. When you'll open it, you'll see it in 1-2 position and you have to put it in 2-3 pin position.

There are 2 jumpers to change position.



In this photo, top, memory 1, bottom, the memory 4. Left memory 1 you can see one jumper and, avobe it, you can see an orange component up. Belowe, the memory 4, the other jumper, it has on its right side a red component.

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Robert Weck
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #6 on: December 10, 2007, 02:52AM »
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Hi Larry,


Quote from: Larry71 on December 10, 2007, 01:52AM   

  Could you please tell me what is referred to as the
"jumpers"?

Maybe Meca could show a picture on his server? (i do not have this as an easy option)

I'm sure, you know, what it is, as you seem to have some  experience in electronics (maybe the term "jumper" is not so common in English?)

It is like a wire-bridge to connect two pins.

Quote:

You seem to have some technical skills.

but only some: i am no "born" engineer or so, only addicted to chess computers and learned some useful things about electronics concerning these.

So do not expect too much from me! 

Quote:

Anyway, I pulled out
the 20mhz crystal and replaced it with a 24mhz crystal.
Considering the frequency halving, I calculated that the
resulting output frequency would be half of 24mhz, ie,
12mhz, giving an overclock of about 20%. Sure enough,
when I tested it on a simple mate-in-6 position I use,
the solving time was about 20% lower.

i have heard, that with newer versions of this machine (like the Cosmos or the Expert Travel Chess) 24 MHz is the highest possible clock speed.

Quote:

But here's the crunch.... the clock on the display is
also increased by about 20%, which I would rather not
happen. This means the quartz chip controls the display
too, and the sound, which now has a higher pitch.

Yes, the clock has no own quartz and the software does not compensate the speed increase, so the clock also runs faster.

This means, that you should select a 20% higher level to make use of the speed increase.

Quote:

  Is there any way you know of that I can underclock the
display back to where it should be while at the same time
leaving the processor overclocked?

I'm afraid, no!


best regards,
Robert
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Larry71
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #7 on: December 10, 2007, 01:52AM »
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Hi Robert, and thanks for the info.
  Could you please tell me what is referred to as the
"jumpers"?
    You seem to have some technical skills. I'd like to pick
your brain a little more if I could: Yesterday I overclocked a
Saitek Travel Champion 2100 slightly. The specifications
give a standard clock speed of 10mhz, but somehow this
is achieved by using a 20mhz quartz crystal. There must
be a reason for this... and to get 10mhz they must have
a frequency halving circuit built in. Anyway, I pulled out
the 20mhz crystal and replaced it with a 24mhz crystal.
Considering the frequency halving, I calculated that the
resulting output frequency would be half of 24mhz, ie,
12mhz, giving an overclock of about 20%. Sure enough,
when I tested it on a simple mate-in-6 position I use,
the solving time was about 20% lower.
  But here's the crunch.... the clock on the display is
also increased by about 20%, which I would rather not
happen. This means the quartz chip controls the display
too, and the sound, which now has a higher pitch.
  Is there any way you know of that I can underclock the
display back to where it should be while at the same time
leaving the processor overclocked? I like it overclocked,
because it made a noticeable difference to it's performance
against Radio Shack 2250XL, which it now beats almost
every game,at 10secs/move, although the 2250 and the Travel Champion
2100 both have the GK2100 program in them. Before I
overclocked they would both solve a problem at the same
time almost exactly.
  all the best to you
  Larry
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Robert Weck
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #8 on: December 10, 2007, 12:13AM »
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Hi Larry,


Quote from: Larry71 on December  9, 2007, 04:53PM   

Hi, and thanks for the info.
  Now all I need is a RISC2500 or a Montreux, both rather
hard to come by. It seems like a simple insertion of the
RAM sticks, just making sure they are in the right way
around.

and setting the jumpers correctly! (i also did such an upgrade)

Quote:

By the way, why did you remove the ARM
processor?

thats not neccessary for the RAM upgrade

Quote:

And while I've got you, does the extra RAM make any
noticeable difference to the performance on either
machine?

2MB is a rather large amount for such a slow (compared with todays PCs) CPU; so you will maybe see no improvement at levels below 30s/move i would estimate.

If your Risc 2500 has 128KB RAM, i nevertheless would recommend this upgrade, as it can improve the performance a little. From 512KB to 2 MB, you will find maybe no improvement...

You can see some test results here: http://www.schachcomputer.info/BT2630-1280.htm

For the Risc 2500 2 MB ("offensiv") you will see nearly no improvement compared to the 512 KB ("offensiv") version (+6 BT-ELO)

For the Risc 2500 2 MB ("normal") compared to the Risc 2500 128 KB ("normal") the result is better: +31 BT-ELO

So one should not set too high expectations in the upgrade (especially, if the machine already has 512 KB)


best regards,
Robert
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Larry71
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Re:Expanding memory: Mephisto Montreux and Risc 2500
« Reply #9 on: December 9, 2007, 04:53PM »
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Hi, and thanks for the info.
  Now all I need is a RISC2500 or a Montreux, both rather
hard to come by. It seems like a simple insertion of the
RAM sticks, just making sure they are in the right way
around. By the way, why did you remove the ARM
processor?
And while I've got you, does the extra RAM make any
noticeable difference to the performance on either
machine?
  all the best
  Larry
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Meca
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Expanding memory: Mephisto Montreux and Risc 2500
« Reply #10 on: December 6, 2007, 04:48PM »
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I offer my experience expanding the memory ram in the SAITEK RISC 2500 and MEPHISTO MONTREUX . I hope it could be useful to another chess computers collector.

All the photos here, this link:

http://www.meca-web.es/articulos/memoryup.htm

« Last Edit: August 5, 2010, 01:56PM by Meca » Report to moderator Logged
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