Path: utzoo!dciem!nrcaer!scs!spl1!ddsw1!bigtex!james
From: james@bigtex.uucp (James Van Artsdalen)
Newsgroups: comp.unix.microport
Subject: Re: HELP! Floating Point Problems
Message-ID: <5695@bigtex.uucp>
Date: 10 Aug 88 02:33:36 GMT
Article-I.D.: bigtex.5695
References: <2424@inco.UUCP> <371@uport.UUCP> <248@belltec.UUCP> <387@uport.UUCP> <252@belltec.UUCP>
Reply-To: james@bigtex.UUCP (James Van Artsdalen)
Organization: F.B.N. Software, Austin TX
Lines: 22

Liberally edited...

In article <252@belltec.UUCP>, dar@belltec.UUCP (Dimitri Rotow) wrote:
> DMA is not the culprit.  If the 386 sees a hold request (for example, in 
> *refresh* time, not just DMA or other phenomena), then one of the necessary
> conditions for Erratum 21 occurs.  Note that memory refreshes happen almost
> continually (every 14 us or so) whereas by that reference scale DMAs occur
> at nearly geologic intervals.

I hate to jump into a good flame war between vendors like this, but one
must point out that refresh is usually done via DMA.  Hence, DMA is done
almost continuously on virtually all machines (PC's Ltd 386/16 being about
the only exception I would guess).

> The citation of "wait state" is 
> misleading, since even a "zero wait state 386" will encounter Erratum 21
> with pre D stepping 386 parts. 

How frequently?  My 386 has no refresh cycles at all.
-- 
James R. Van Artsdalen    ...!uunet!utastro!bigtex!james     "Live Free or Die"
Home: 512-346-2444 Work: 328-0282; 110 Wild Basin Rd. Ste #230, Austin TX 78746