Overview

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:


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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 smile.gif).

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.

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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.

So... Second Switch changes only language of program library. My calculator has GERMAN as standard and FRENCH as second.

Standard, R22 is closed, and... R23? (dunno, calculator closed already...) open.
Second: R22 open, R23 closed.