28 replies to this topic

[liquid]

I have found that peple can overclock their cfx's.
Ive got a fx 9750 G plus and i took it apart and found the 3 pin 4.3 mhz smd ceramic resonator.
My question is, can i use a non smd ceramic 3 pin ceramic resonator.
Does it have to be a smd in otherwords.
I also have a 2 pin 6mhz one, is it possibe to use a 2 pin instead of three, and iff so how is it hooked up?

[huhn_m]

I think the overclocking was made by changing the quartz or sth. like that. I?m not too experienced at such detailed technics. But it should be possible.

Also welcome to the UCN!!

[liquid]

Speaking of overclocking, does anyone know how to overclock a Casio CFX 9850GB+?

Well that shoud be the same as trying to overclock my 9750 G plus(the layout might be a bit different though).
both of our calcs have the 4.3 Mhz resonator, and it would have to be replaced by one of a higher speed.
Open up ur calc and take a look if u want.
I just want to know if it matters if i replace the smd reonator wif a non smd one as these are much easier to obtain.
And can u use a 2 pin one (the one in the calc is three pin), and if so , how can it be hooked up.

Seems no one knows much about this on the UCF, but they do on the DCF, buts thats in german and translates badly.
Cmon, there must sumone else whos done this around here???!

[Marco]

As far as I know, SMD is just the shortcut for Surface Mounted Device and means nothing but the method how to get the thing onto the board (SMD devices are soldered directly onto it without pins or wires; you have blank areas with flat contacts)

So the resonator should work also if it's non SMD. (btw I looked up the thread in the DCF again and rockclimber reported on July 21th 04 that it "should be no problem to solder a non SMD resonator onto the board, too")

As for 2<->3 pin question, sorry, I really don't know sth about it. But I guess 2 pin will not work, the third one probably isn't just for fun However, you should ask Marcel, Matze or Rockclimber for that, they're the most skilled with it (you could call them the pioneers of CFX overclocking). But you'd better write them a mail as I haven't seen them on the DCF for a long time (and I'm sure they'll also understand it in English )

[liquid]

Thanks a lot Marco, i might as well spend a small amount on a 3 pin res to save me any trouble. When i try this(not now as i need my calc going for uni), prob in holidays i will post the results up here for non german speaking ppl to look up.

[Bob Vila]

try http://www.geocities.com/techfreak02/

edit--
eh, maybe not i guess this is only how to upgrade your memory

Edited by Bob Vila, 28 February 2005 - 09:04 PM.

[Marco]

Can anyone provide a link to a site or provide a step-by-step tutorial to overclock a Casio CFX?

A site about it doesn't exist, though around 10 people overclocked their calcs already Marcel never updated the techfreak site. It still gives a tutorial only how to upgrade RAM on the old black calc, while upgrading the new blue/white calcs is even much easier.

OK so I'll give a short summary of the upgrading and overclocking Threads in the DCF made by Marcel, Matze, Rockclimber, Flori, Astrofreak, StarTrekMichi, foxtanz, Nukeduke, dr.jons and others:


Overclocking

Don't use a quartz pulse generator, it MUST be a resonator. Some tried it with a quartz but had problems with switching the calc on/off then; id didn't work really proper.

With resonators there have been no problems, and it also needn't to be an SMD. Frequencies tested successfully were 6MHz, 7.38MHz and 8MHz. 8.6MHz was also tested but didn't work anymore, seems this was to much for the calc. You can get SMD resonators at the most electronical handicraft shops for around 30 Cent.

The procedure of overclocking now is relative easy. Open your calc and look for the original resonator @4.3MHz (there's only one inside. It has a metallcase, 6 pins that look like only three (but you have them at the left and the right side, thus 6) and it's bigger than the other SMD stuff. Next to it you have a label "X" or "X1". See picture below). Just unsolder it and solder the new resonator there. That's it, and it works the same for the old (black) and the new (blue white) calcs (The only thing that's a bit tricky is that it's SMD what you solder, look my above post what SMD means. But note, you also may use non SMD ).

Overclocking your calc will make the batteries discharging quicker, but it's not reported how much quicker. Also overclocking brings another problem: calcs COM port runs at 9600 baud originally, but synchronised by that resonator. Replacing it with an 8MHz one for example will make the COM port running at 17860 baud, and the calc isn't able to communicate with other calcs or the PC anymore (also selecting baud rate on your PC manually will not work).

A solution was using two resonators, the original and a fast one, and make it selectable by a switch wich one you want to use. I don't know if anyone has done that yet.

Upgrading RAM on the new blue/white calcs

Some poeple requested for a tutorial how to upgrade the blue/white calc's RAM (for the old black ones this is described on the techfreak site already). Yesterday, rockclimber visited the DCF again and posted how to do this:

- open the calc
- look for the R20 and R21 resistor labels
- at R21, you have a resistor with 0 Ohm wich is nothing but a closed bridge
- R20 is left open (open bridge)
- unsolder the R21 resistor in order to make it an open bridge
- close the R20 bridge (you can do this either with the resistor from R21 or with a piece of wire).

That's it, your calc has 64KB now.

What I find very interesting is the way how rockclimber found out how to upgrade the RAM on these calcs - he just compared the board of the blue/white CFX9950GB Plus, wich is actual a CFX9850GB Plus with 32KB more RAM, with the board of this. The R20/21 resistors obviously have been the only difference.

Thus, each blue/white CFX9850GB Plus in fact HAS 64KB (that's another thing for the black calc where you have to build in a second RAM chip), but Casio disabled the upper 32 in order to have a reason making the CFX9950GB Plus more expensive

Actual I never thought of upgrading the RAM of my blue/white CFX9850GB Plus myself, but when I heared today it really should be THAT easy, I just couldn't resist and opened my calc some hours ago, willingly to make this RAM upgrade. Here's a picture of it:



But then courage left me and I wasn't brave enough to do it. I thought a CFX with 32KB mem is worth more than one with 64KB that doesn't work, so I coward closed my calc quickly.

And here is a picture made by Rockclimber: http://www.geocities...02/solder_4.jpg

[liquid]

Marco, u should look at the part # on that ram chip, can u tell me if u can.
My blue + white 9750 has 32kBram and after looking up the sram chip on
http://www.hynix.com/eng
it was a 32KB chip, so i wont be able 2 upgrade my ram 2 64KB

Is your ram chip a hynix one or other brand, can u tell me becuase hynix only comes in 256Kbit and 1Mbit,,,,,but 64KB is 512Mbit ???
I cant see the part # on your picture its too low res
If u dont want to open your calc again i understand

[genesis]

Wow, is it really that simple? Wouldn't you be able to use the extra memory in exams? I'll probably leave my 9850 alone, after all, you shouldn't need to have 64 KB (and yes, I've already screwed up one of mine...)

[Marco]

@guest: Thank Marcel, Matze, Rockclimber, ..., I just summarized what they found out.

@liquid: I screwed it up again, the SRAM was BS62LV1024SC-70 (BS62LV1024 series, manufacturer is BSI). The data sheet says:

70ns 20-35mA 2.4-5.5V very low power/voltage CMOS SRAM 128K x 8bit in 32-pin SOP package.

So it's even 128(!) KByte, not 64 only. Therefore I looked up the DCF's RAM thread again, Matze also said blue/white CFX 9850GB Plus/ 9950GB Plus use the same SRAM chip, and it's 128KByte. OS however can manage 64KB only.

So I wonder what's the reason. I think 128KB also would not make batteries discharging quicker, as the whole chip get's power anyways, just the upper address pins aren't connected (or is it possible to disable a RAM chip's power supply segmentwhise? Don't know). One possible reason might be if an 64KB SRAM also would not be cheaper than 128KB, and Casio didn't want to update the OS.

So it'll work this way for blue/white 9850 only, not for your 9750, sorry (nobody upgraded a 9750 yet). Maybe you could upgrade RAM similar to the black calc where you also need a second RAM chip, but that'll be more complicated. If you'd like to try it, you should ask Matze or rockclimber. Maybe they can tell you how to do.

[PerCasioAdAstra]

this looks neat. Better try this, as soon as my exams are over

[R00KIE]

Don't forget that overclocking drains the batteries faster !

[liquid]

Excellent work!
Great to know there are still some people hacking this calc lol
Thanks for the advice on the 2 pin resonator, u see i got a 2 pin 6 Mhz one from a broken mouse, might try it out.
Maby once i get into elec engr i will rom read my calc and continue the legace, but probably not lol,
bye

[demolitionb]

thx to this thread, it helps me to overclock my cfx 9850g to 8 MHz....

But I miss some Tutorials in the www, so i wrote my own one on my Blog with some Pictures... klick me .... hm, the link funktion does not work, so see there:
http://einfachnurbe....erclocking.html

Only one, I'm a german guy and the tutorial is in german too....
And when somebody like my Blog he can get the feed