Re: Problems with Alsys 386 V5.1.1 Compiler

[cis.ohio-state.edu!math.ohio-state.edu!sdd.hp.com!col.hp.com!csn!news.sin et.slb.com!news.london.sinet.slb.com!news@ucbvax.Berkeley.EDU (Mathew Lodge)]

In article 51b@issi-gw.issi.com, houston@issi.com (Sam Houston) writes:
> In article AA25446@cs.utexas.edu, CZinsmeyer%TSS%SwRI05@D26VS046A.CCF.SwRI.ED
U () writes:
> >I'm developing an application for the U.S. Air Force
> >                     After some period of time, usually twenty minutes or 
> >so, the system begins to slow down.  The longer the system runs the slower 
> >things get.  
> 
> I remember hearing of a similar problem in the development of the
> Patriot Missle system.  It had something to do with floating point
> precision and the clock.  I don't remeber the details, but you
> might want to see if you can find the information.

I thought that the Patriot Missile system got *less accurate* as time went by, 
since in some calculation they were dividing through by the elapsed time using 
fixed point arithmetic. As time went by, the elapsed time counter got larger, a
nd so more and more precision was lost on the divide.

That's the version I heard... anyone really know?

I really don't think it is in any way related to the Alsys bug.

> Sam Houston

Mat


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