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How are random numbers generated in Casio fx-570MS?


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#1 rorymyrory

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Posted 19 November 2016 - 02:31 PM

What is the entropy source or seed values for the Rand# series of functions in Casio fx-570MS? And what algorithm is used to generate the numbers?



#2 frankmar98

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Posted 13 January 2017 - 06:40 PM

Hello, this is a difficult question, if anyone has reverse-engineered the calculator.

 

I believe that every binary device with a microprocessor has some device that gives the time to the microprocessor, to execute the instructions constantly, so there is a system time given by some hardware device.

 

This system time can be used as seed for the Montecarlo algorithm or other algorithm.

 

If this is false, I can't see other seed.

 

About the algorithm:

Some people in the forum said that the fx-991ES /115ES /570ES ... etc have SH1 or SH2 microprocessor. But the microporcessor of your calculator is unknown.

 

By knowing the microprocessor, you can search in some manual if there exist an instruction for generate random numbers, then there are calculated by hardware, or if this instruction don't exist, you have to dump the ROM and disasemble it, what is very very difficult.



#3 SopaXorzTaker

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Posted 14 January 2017 - 12:15 PM

Hello, this is a difficult question, if anyone has reverse-engineered the calculator.

 

I believe that every binary device with a microprocessor has some device that gives the time to the microprocessor, to execute the instructions constantly, so there is a system time given by some hardware device.

 

This system time can be used as seed for the Montecarlo algorithm or other algorithm.

 

If this is false, I can't see other seed.

 

About the algorithm:

Some people in the forum said that the fx-991ES /115ES /570ES ... etc have SH1 or SH2 microprocessor. But the microporcessor of your calculator is unknown.

 

By knowing the microprocessor, you can search in some manual if there exist an instruction for generate random numbers, then there are calculated by hardware, or if this instruction don't exist, you have to dump the ROM and disasemble it, what is very very difficult.

Not SuperH, the architecture is now known to be nX-U8/100.



#4 frankmar98

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    fx-3650pII PB-100
    fx-991SP X fx-991ES plus

Posted 14 January 2017 - 12:19 PM

Not SuperH, the architecture is now known to be nX-U8/100.

In the MS models also?






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