CASIO fx-3600P scientific calculator from 1985

[Csaba Tizedes]

(06-01-2018 10:01 AM)xerxes Wrote:  

(05-31-2018 05:47 PM)Csaba Tizedes Wrote:  I have one workable but not so good shaped CASIO fx-6300G. If inside I found a crystal oscillator, can I try to change it?

I've overclocked my FX-6300G from 0.8 to 2.6 MHz many years ago and it still works flawlessly.
In the case of the FX-6300G, you only need to change the resonator.

Xerxes: the 3.2MHz is tested: turns on with only RESET and must to set the contrast. After that works, but if you turned OFF it can not to turn ON again, only with RESET. I wrote a little counter on it and measured the ~4× speed increase. After few RESET something went wrong and some trash generated in the program memory and after few OFF/ON cycle totally failed. I have removed batteries and I will soldering a little slower oscillator if I can find in our electronics store.

Thanks for the tips, it seems to me this will works.

The other project: I have dismantled my all CASIO fx this weekend and I decided I will speed-up my 3800P, because it has 220k resistor also on the motherboard and it has four program slot. I have calculated a good parallel resistor for it and I will use thermistor. With a little counter program stored in one slot I can measure temperature with my calculator, I need to calibrate only. Currently I need to measure the upper frequency limit, I will install a little 220k trimmer to find the limits of the calculator and I will install a few kOhms shift to set the maximal frequency and I will use a 100kOhm thermistor to measure temperature on the range 0°C ... +50°C.

If I have any result I will post a new topic for that.

Thanks again,
Csaba

[edryer]

According to "Your Computer" (UK Magazine) December 1982...

Quote:CASIO FX 3600P
2 program areas, 38 steps, 7 memories. 10 + 2 digits. 50 scientific functions,
including Integrals and Regression. Standard deviations, R/P & P/R
conversions, 18 levels of parentheses
£22.95

So this is actually a 1982 device originally... I am surprised as I also thought around 1984/1985, your model must be a later production version. At the time £22.95 was likely around $50.00.