Power supply for Saitek Kasparov RISC 2500?

[qubit]

I just picked up two Kasparov RISC 2500s in a thrift store. (Yeah, I know. Pretty cool thrift store.) Neither one had a power supply with it. The boards are asking for 5.6v, 1a, center positive -- the closest thing I have is 5v, 1a, center positive. I read a couple things on the net that said I couldn't hurt electronics by undervolting them if the current and polarity are right, so I gave them a shot -- both boards power up and seem to work fine, but I haven't yet given them any significant testing. Can anyone tell me if there's a good reason not to use 5v adapters with these boards?

Also on the subject of supplying power, both these boards have what looks like battery compartments, but they don't have the metal springs and strips that are supposed to make contact with the batteries. The battery compartments are just sealed plastic boxes. Is this typical for the RISC 2500, like Saitek saved money by reusing the bottom casing part from a different model? I've never seen anything like it.

[Larry]

I just picked up two Kasparov RISC 2500s in a thrift store. (Yeah, I know. Pretty cool thrift store.) Neither one had a power supply with it. The boards are asking for 5.6v, 1a, center positive -- the closest thing I have is 5v, 1a, center positive. I read a couple things on the net that said I couldn't hurt electronics by undervolting them if the current and polarity are right, so I gave them a shot -- both boards power up and seem to work fine, but I haven't yet given them any significant testing. Can anyone tell me if there's a good reason not to use 5v adapters with these boards?

Also on the subject of supplying power, both these boards have what looks like battery compartments, but they don't have the metal springs and strips that are supposed to make contact with the batteries. The battery compartments are just sealed plastic boxes. Is this typical for the RISC 2500, like Saitek saved money by reusing the bottom casing part from a different model? I've never seen anything like it.

Firstly, congratulations on your find. Out of curiosity, how much did they cost you? Chess computer processors run on a lower voltage than the adaptor
delivers, and they have a voltage regulator to drop the voltage. The regulator
needs a small load to do its job, that's why the slightly higher voltage is used.
The voltage coming in from the street can't be relied upon to be steady. Keep
a lookout for an original HGN5050 adaptor anyway.
The r2500 casing was designed for an earlier, less power consuming
model, and it's not suitable for batteries. They would not last long enough.
That's why there are no contacts in the battery bay.
Did the two r2500,s come complete with original boxes, pieces and owner,s
manuals?
Regards....Larry

[Steve B]

Seems Risc 2500's are all the rage recently:

http://www.ebay.com/itm/291370811803?_t ... EBIDX%3AIT

How Many MB Regards?
Steve

[Larry]

Seems Risc 2500's are all the rage recently:

http://www.ebay.com/itm/291370811803?_t ... EBIDX%3AIT

How Many MB Regards?
Steve

Note the seller describes as a "negative" the fact that the game clears its
ram on shutdown. I thought this was normal because the owner,s manual
actually tells you to power up in a way that deliberately clears the ram.
It seems the r2500 does have bug in its software in that the ram
does not re-allocate. This is why there can be an occasional freeze-up,
and you have the annoyance of having to reset via the "acl" button. The
later Montreux does not have this problem.
Still, I think we can all agree the r2500 is a better looking unit than
Montreux. As a bit of trivia, I recently noticed that on power- up, the
r2500 playing style defaults to "normal" , while the Montreux defaults
to "active".
L

[Mach2000]

Note the seller describes as a "negative" the fact that the game clears its
ram on shutdown. I thought this was normal because the owner,s manual
actually tells you to power up in a way that deliberately clears the ram.

I just bought such a beauty recently and had the same problem. After replacing the CR2032 everything works fine. All settings are saved.

It seems the r2500 does have bug in its software in that the ram
does not re-allocate. This is why there can be an occasional freeze-up,
and you have the annoyance of having to reset via the "acl" button. The
later Montreux does not have this problem.
Still, I think we can all agree the r2500 is a better looking unit than
Montreux. As a bit of trivia, I recently noticed that on power- up, the
r2500 playing style defaults to "normal" , while the Montreux defaults
to "active".
L

A lot of Risc 2500 machines work with an eprom of the Montreux, so if you want the beauty of the Risc and the program of the Montreux that should be possible

Regards Mike

[qubit]

Thanks for the help re: power supplies. I think they're both going on eBay honestly. I love chess but these things take me apart like demonic surgeons. They're both 128k ROM, 128k RAM.
They were five bucks each... only one had pieces, and there weren't any boxes or manuals, but I can't exactly complain.

[qubit]

I've got the first one up on eBay -- going to hold off on listing the second one until I can source some replacement pieces for it.

http://www.ebay.ca/itm/Saitek-Kasparov- ... 1666413990

Feel free to make an offer by PMing me on this forum.

[Stephen J]

Note the seller describes as a "negative" the fact that the game clears its
ram on shutdown. I thought this was normal because the owner,s manual
actually tells you to power up in a way that deliberately clears the ram.

Hi Larry, It's my RISC 2500 on UK ebay. I mention the RAM clearing as a negative, because it is not saving the game position if you decide to switch the power off half way through a game.

Regards, Steve J

[Stephen J]

Seems Risc 2500's are all the rage recently:

http://www.ebay.com/itm/291370811803?_t ... EBIDX%3AIT

How Many MB Regards?
Steve

Hi Steve, 0.128 MB

Regards decimally(?)
Steve J

[Stephen J]

Note the seller describes as a "negative" the fact that the game clears its
ram on shutdown. I thought this was normal because the owner,s manual
actually tells you to power up in a way that deliberately clears the ram.

I just bought such a beauty recently and had the same problem. After replacing the CR2032 everything works fine. All settings are saved.


Regards Mike

Hi Mike is that a difficult/expensive task for someone who is electronically compromised?

Regards, Steve J

[Mach2000]

Hi Mike is that a difficult/expensive task for someone who is electronically compromised?

Regards, Steve J

Hi Stephen,

if you're used to using a soldering gun it's not a difficult task. I took out the old, empty battery and installed a battery holder (for future battery changes). I placed the battery holder for the CR2032 in the unused battery compartment (and used longer wires to connect it to the logic board) If you remove the hot glue from the cover of the battery compartment, you'll be able to access the battery holder without having to open the case. Battery and holder cost about €2.

Regards Mike

[qubit]

Whoa, that's smart! What a great, simple mod.

[Reinfeld]

Good god, five bucks each? You're killing me.

- R.

[Stephen J]

Hi Mike is that a difficult/expensive task for someone who is electronically compromised?

Regards, Steve J

Hi Stephen,

if you're used to using a soldering gun it's not a difficult task. I took out the old, empty battery and installed a battery holder (for future battery changes). I placed the battery holder for the CR2032 in the unused battery compartment (and used longer wires to connect it to the logic board) If you remove the hot glue from the cover of the battery compartment, you'll be able to access the battery holder without having to open the case. Battery and holder cost about €2.

Regards Mike

Thanks Mike that's good to know, although I probably would not attempt that myself.
Regards

Steve J

[Brian B]

Good god, five bucks each? You're killing me.

- R.

Yes, I paid the market rate for mine, too. Did I miss a trend here? Are prices really climbing on the Risc 2500? I mean other than thrift store purchases. It seems to me that prices are generally down across the board the past couple of months or so. Of course, some computers are always in demand, but still. Not looking to sell, just curious.

Regards,
Brian B