🚀 go-pugleaf

I have a Zeos 386 computer in which I installed a Cyrix 83D87
math co-processor last summer.  When I tested out the co-processor,
I discovered that the error line was inoperative; i.e. if I
try to use the co-processor to perform some illegal arithmetic
operation, I get a default result instead of an error signal.

For example, when I run the following Turbo Pascal program:
{=============================================================}
program COPTest (output);
{$N+,E+}
var
  x,y:  extended;
begin
  x := 0.0;
  y := -1.0;
  writeln ('Divide by zero test:  ',5.0/x);
  writeln ('sqrt(-1) = i = ',sqrt(y))
end.
{==============================================================}
I get a run-time error on another PC (using a co-processor with
an operative error line) but on MY machine I get:

    Divide by zero test:  0.00000000000000E+0000
    sqrt(-1) = i = -1.00000000000000E+0000

A Northgate 386 using a Cyrix co-processor correctly reports a
run-time error when running this program, but my Zeos 386 gives
these default values (and I have tried TWO different Cyrix
co-processors).

Does anyone have a Zeos 386 PC with an Intel 80387 who 
could test the co-processor error line (such as with the above
program)?  I would also appreciate hearing from anyone who has
had a similar problem.  (I suspect the problem is somewhere in
the motherboard.)

Thanks for any info!
                                David Simpson