Solved

About the turbo pascal random number  generator

Posted on 1998-12-02
1
1,593 Views
Last Modified: 2010-10-05
What is the explicit definition of the linear congruential random number generator used in turbo pascal, i. e., what are its multiplicative constant and its modulus?
0
Comment
Question by:amitapal
1 Comment
 
LVL 4

Accepted Solution

by:
jack_p50 earned 50 total points
ID: 1216268
Here are how TP6 and TP7 random works :


const
  rseed: longint = 0;

procedure randomize67;      {TP 6.0 & 7.0 seed generator}
begin
  reg.ah:=$2c;
  msdos(reg);    {get time: ch=hour,cl=min,dh=sec,dl=sec/100}
  rseed:=reg.dx;
  rseed:=(rseed shl 16) or reg.cx;
end;

function rand_word6(x: word): word;    {TP 6.0 RNG: word}
begin
  rseed:=rseed*134775813+1;
  rand_word6:=(rseed shr 16) mod x;
end;

function rand_word7(x: word): word;    {TP 7.0 RNG: word}
begin
  rseed:=rseed*134775813+1;
  rand_word7:=((rseed shr 16)*x+((rseed and $ffff)*x shr 16)) shr 16;
end;

function rand_real67: real;    {TP 6.0 & 7.0 RNG: real}
begin
  rseed:=rseed*134775813+1;
  if rseed<0 then rand_real67:=rseed/4294967296.0+1.0 else
  rand_real67:=rseed/4294967296.0;
end;
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

If you are looking at this article, you have most likely been hit by some version of ransomware and are trying to find out if there is anything you can do, or what way you should react - READ ON!
This article describes my battle tested process for setting up delegation. I use this process anywhere that I need to setup delegation. In the article I will show how it applies to Active Directory
This video shows how to quickly and easily add an email signature for all users on Exchange 2016. The resulting signature is applied on a server level by Exchange Online. The email signature template has been downloaded from: www.mail-signatures…
Nobody understands Phishing better than an anti-spam company. That’s why we are providing Phishing Awareness Training to our customers. According to a report by Verizon, only 3% of targeted users report malicious emails to management. With compan…

840 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question