Floating point problems

[Tony Facca]

[Becky Marvil] writes:

> I've been having floating point problems on an Iris 2400 turbo 
> running version GL2-W3.5, and was wondering if anyone can help.

  [ stuff about floating point problems deleted ]

> If anyone has a clue as to what my problem is, I would appreciate
> a response.  One possibility, I suppose, is that the fpa board
> is screwed up.  If so, is there a way to bypass this board and
> have the software do floating point operations?

We've had similar problems in the past on our 3030's and in every instance
it turned out to be the fpa board.  A quick check that we use is a simple
program which loops from 0 to 100 and prints out the integer and floating
point value at each interation.  Its written on FORTRAN so we compile it
first with, then without the floating point option:

   [with]  f77 -Zg prog.f -o prog

   [w/o]   f77 prog.f -o prog

I wish I had a bad fpa board to test this on :)  but I think that's how we
found the problem.  I'll send the source directly rather than posting it
here..  

Hope this helps..


--
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Tony Facca                     |     phone: 216-433-8318
NASA Lewis Research Center     |    
Cleveland, Ohio  44135         |     email: fsfacca at lerc08.lerc.nasa.gov
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