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Random Number Generators have been studied extensively during the computer age and a large body of documentation exists. Delphi's Random function is limited to 32 bits, about 4 billion.    When I had a need for random integers up to 300 billion recently, I thought that finding a 64 bit Delphi or Pascal version would be simple.   There are plenty of C-whatever examples, but not so many on our side of the fence. 

I ended up installing two versions into our MathsLib unit.

For Delphi versions after D7, I used the Random64 function by J.R Stockton found at http://www.merlyn.demon.co.uk/programs/mathutys.pas.  It uses the unsigned 64 bit integer type UInt64, and so cannot be used in D7 and earlier versions.  For those compilers I wrote a Random64 function which converts a passed Int64 integer to  a TInteger big integer type and pass that to the Random procedure in our UBigIntsV4 unit.  The returned value is converted back to an Int64 type and returned to the caller.

I plan to do more statistical testing of these functions and perhaps locate or develop a function that will work for both early and later Delphi versions.  Windows has a native "CryptGenRandom" function if I find the appropriate API to allow Delphi to use it. 

The current routines are located    


Links to Explore


 Running/Exploring the Program 


Created August 13, 2013

Modified February 18, 2016



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