Hello friends

How do I OPEN a Radio SHACK chess master or 2200x without breaking it - I took all the screws out but it is stuck and won't come apart so I can tune it.

Can someone please provide instructions on opening the Radio Shack computers

THANK YOU
Queegmeister

Hello,
on the homepage of Alan Zanchetta you can find many instructions.
Also from Radio SHACK.
With "Chess Computers" Pressures on "Documentations".
Open the pull-down menu and select your manufacturer.
Now the instructions for download are provided.

Link zu Alan Zanchetta

Regards, Rüediger

__________________
shine on...

Hello Friends

I have dissected the Radio Shack but do not see an oscillator to replace - is there something I am missing ? How can this computer be tuned ?

Thanks
Queeg

Hi Queeg,

the 2200x is a Morsch GK2000 (16 K rom) with clock division.
It will have a 20 Mhz oscillator or resonator.
You can identify a resonator by a blu color, it looks similar to a condensor.
The printing on the resonator should be 20M (means 20 Mhz) and the computer runs with 10 Mhz.

To double the speed you need a 40 Mhz resonator, but in most cases you have to change the voltage (from 5v to 6v), thats only possible for an experianced electronics engineer. Maybe some colling is needed.

Easier to tune is a newer GK200 without clock division, like the Saitek Explorer. It has the same program but can run at 4 times speed.

Regards
Achim

Thank You for the information

I wonder if I can Tune the RS Master - Is this the same situation ?

And with the right instruction I'm sure I could do it.

do I need to raise the voltage for this as well ?

The computer runs on 9v as you know but the rest is a mystery to me for now.

I do not understand your reply that the voltage needs to be raised from 5v to 6v

Do you mean that 5 volts is what the resonator is receiving by means of resistors ? I can replace resistors.
I am able to read the bands on them.

THANKS

QUEEGMEISTER

Hi,

I assume that RS Master 2200x and RS Chess Master are the same items.
Both are old versions of the GK2000, only the housing is different.

If you find the resonator or oscillator you can try to change it.

If it has 10 Mhz, that you are lucky, it is a new GK2000 and you can try 20 or 30 MHz instead, sometimes 40 Mhz will run.

If the computer do not start or crashes in a game, then higher voltage for the CPU is needed (6V instead of 5V). This has nothing to do with the voltage adapter outside the computer, there is an internal regulation to reduce the voltage to 5V. But to change this, you need electronic experience - otherwise the item will be damaged.

If you have a 20 mhz resonator, you can only try 30 or 40 Mhz (50% or 100% more speed). 40 Mhz will not run in most cases (see above).
If you want to try 30 Mhz, you need the correct levels. To play a 30 sec/move game you have to set it to 45 sec/move. Or 4,5 min/move instead of tournament level (3 min/move). If these levels are not available, tuning makes no sense...

Regards,
Achim

Will a quartz crystal resonator work for replacement on these types ?

I have 1-48 mhz quartz crystal oscillators. but they don't look anything like the resonator in the RadioShack.

these are what I have (in the range I mentioned)

http://www.ebay.com/itm/10pcs-2x6mm-...item460fa573db


would I rather need this kind ?

20pcs AT26 Quartz Column Crystal Resonator DIP 40KHZ | eBay

or some other like a ceramic type ?

Thanks
mike

Hello Mike,

these little oscillators are not available with 30 or 40 Mhz, your 2nd link shows a 32 khz version (Khz not Mhz) and is much too slow.

Most quartz oscillators geater than 25 Mhz run in 3rd overtone, if you use such items, the computer will run slower then before, because in groundtone mode it will use a divisor of the named frequence (e. g. 32 MHz overtone has 8 or 16 Mhz groundtone).

You will need something like this:

https://hbe-shop.de/QUARZ-3200-MHZ-GRUNDTON
https://hbe-shop.de/RESONATORZTT30MHZ
https://hbe-shop.de/RESONATORZTT40MHZ

The middle pin of the resonator is not needed in most cases...

Regards,
Achim

THANKS !!

so basically , every oscillator I bought in the "kit" above 25 mhz is useless

Why make them - if they will not help ?

Thanks , now I understand much better.

Queegmeister

Hi,

you have to check your oscillators if they are groundtone types or 3rd overtone (data sheet).

Overtone oscillators are much cheaper than groundtone ones, but they need a specific circuit to start in the right frequence. Modern hardware can use these types without problems.

The old chess computers do not have that specific circuit and are designed for oscillators < 25 mhz in most cases. You cannot change the basic circut easily and so high frequency oscillators will not run, if not in groundtone.

So I and others were looking for these special oscillators/resonators for a long time and are happy to find some. Only with these rare types tuning of old hardware makes sence. And there is no guarantee that it will work, it depends on the quality of the cpu/ram. E. g. we tried the same chess computers (Atlanta) and some work with 40 Mhz + high voltage, some only with 30 Mhz + high voltage, others with 36 Mhz and standard voltage - every item is a little bit different in the behaviour during overclocking.

Regards,
Achim