I think overclocking functions are a bit overpowerd, I mean, if it could damage the calculator why would you use it, only to take the risk? How do I if know someone use it. How do I know iof add-ins are not destoying the hardware of my calculator? If you release that stuff?
Don't worry about it, the CPU in the fx-9860 is able to handle up to 133MHz. The power consumption is consistent even if you change the frequency. I think the fx-9860 has long battery usage (If I remember, over 200 hours of non-stop use). I've been running my calculator at quadruple speed (if the oscillator is running at 40MHz, that means I'm running at 160MHz! If the oscillator is instead at 20MHz, then I'm running at 80MHz) for about a day now and nothing has happened yet.
Awesome ! I want more speed !!! 
Thanks!

brilliant kucalc (you should rename yourself to kungfucalc
)
That would be an awesome name!

also a question, is it also possible to clock the cpu down? it could be a very nice feature for energy saving, for example in submenu's or while waiting (i write non cpu intensive programs for my job (simple calculations with many many parameters) and this could help the battery consumption)
whehehe i bet a casio doomsday device...I wouldn't be surprised kucalc turns out to be dr. evil opting for world domination...
You can slow down the calculator down to a fourth of the oscillator. But as I said earlier, changing the CPU speed doesn't affect power consumption. The CPU is very consistent. The CPU only needs 2.0v to function even at 133MHz. We should do a test to prove this. Who is willing to leave their calculator running non-stop?
GOOD JOB 
I would love to see how you did it. I think you must have found the Timers Watchdog Address.
I tried vanhoa 3d drawer with more speed and it is amazing.
Awesome, note that the USB speeds won't change. The USB uses a different clock source. I could change the frequency of the USB also if you want, however I don't think it will be able to communicate with the PC anymore.
Very good work kucalc. I love your speedup program.
Why not an Addin with selectable frequency with warning of using on own risk? But I don't think that it is really a risk. For example it is possible to overclock the HP-50G by software to 150 MHz instead of 75 MHz without problems or to 233 MHz with problems. 
Well, currently I'm seeing no problems with the CPU speed quadrupled. I'll re-release it again when I have the time. The CPU speed is determined by multiplying the oscillator speed by a constant. If you changed the adjustable oscillator in your calculator and set it to 60MHz (the oscillator can be adjusted to 160MHz), then after running my CPUSPEED program, you CPU will run at 120MHz. LOL! If you changed the speed of the oscillator to 160MHz, then running my CPUSPEED program will give you 320MHz! Quadrupled: 640MHz (The fastest handheld graphing calculator in the
WORLD!)!!!! But your fx-9860 will be absolutely fried up. About 100MHz is still fast though and you're not really overclocking when at 100MHz, since the CPU can take 133MHz.
Hey Xerxes, can you run your speed comparison program again (after running my CPUSPEED program) and give me the results? It would be nice if you could do that.