Item Subject: Don't just worry about Pentiums!
I ran the calculation on a 937/SX running MPE/iX 4.0 using the CALC
command.  Got "1050108, $1005FC, %4002774" as a result, which looks a
lot like your IBM.  I then tried it in Qedit, with the "=" command, and
received ".0" as the correct result.  Does it have something to do with
the way decimals are rounded?.  CALC (4195835/3145727) only gives a
result of 1, rather than Qedit's "1.33382044914".  Try 5 - ((5/2)*2).
CALC gives you "1", Qedit ".0"
 
Russ Johnson
DCBU McMinnville
 
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Subject: Don't just worry about Pentiums!
Author:  Non-HP-owner-hp3000-l ([log in to unmask]) at HP-Unix
Date:    1/4/95 8:49 AM
 
 
As noted by one of our CompSci professors at UTC, Pentiums aren't the only
things to be worried about:
 
> I sent out a calculation which causes the Pentium to produce answer
> 256 when the "correct" answer is 0.  If you run the same computation
> on our IBM ES9000 (in either FORTRAN or C) you get the following
> results:
>
>  INTEGER     REAL         LONGINT   DOUBLE
>  4195835  4195835.000000  4195835  4195835.000000
>  3145727  3145727.000000  3145727  3145727.000000
>  1050108        1.000000  1050108        0.000000
>
> Bottom row should produce value 0
 
Of course the integer calculations would be wrong, but it misses the
boat on single-precision reals!  (The ES9000 is this machine, utcvm.utc.edu)
 
The calculation is:  4195835 - ( (4195835/3145727) * 3145727 )
 
Our HP960 does it correctly with both float and double, as did one
of our Suns.
 
Apparently it's a function of IEEE floating point versus the IBM's
goofy floating point format (wonder what a classic 3000 would say?)
 
[\] Jeff Kell, [log in to unmask]