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From: rfh@tahoe.unr.edu (Randy F. Hall)
Newsgroups: comp.lang.pascal
Subject: HELP with Turbo Pascal problem
Keywords: Turbo Pascal
Message-ID: <3433@tahoe.unr.edu>
Date: 6 Jan 90 02:44:25 GMT
Reply-To: rfh@unssun.nevada.edu  (J.A. MacDonald)
Organization: University of Nevada, Reno
Lines: 44

HELP!!

  I wrote the following program in TurboPascal 5.5 and got a very
wrong answer. One would expect to get an output value for j of 64516,
but instead get -1020. The only explanation I could think of was that
there is a screw up in the 2's compliment or something. I also tried
running it through TP5.0 and on other machines, but with the same result.

  It has the same problem whether j is defined as a LONGINT or REAL. 
Also for i = 255, -255 and -254. I haven't tested for any other values.
Replacing i * i with SQR (i) didn't help either.


-------------------------

Program test;

Var 
  i : integer;
  j : real;

begin 
  i := 254;
  j := i * i;
  Writeln (j);
  Readln;
end.

-------------------------

  If anybody has any idea what may be the problem, let me know. I can
get around the trouble (fortunately) by using WORD declaration for j as
j will never get above 65535. In the future this may be a problem though.

	Thanks in advance

		JaM


real BMW's have only two wheels
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rfh@unssun.nevada.edu      | I lit out from Reno
                           | I was trailed by twenty hounds...
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