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Greg A. Woods woods@weird.com
Tue, 4 Mar 2003 13:18:34 -0800 (PST)
[ On Tuesday, March 4, 2003 at 09:12:44 (-0500), Mike Daigle wrote: ] > Subject: Re: Solarus 8/9 Sparc Questions > > The only solution which I have found that gives satisfactory > results is the Nudata(TM) Non Aborting Serial Port Adaptor. This > is a little black box that cost about $90. It has smarts onboard > and allows the BREAKs to be sent from a terminal or terminal > server port. But it monitors the DTR line, if it drops then the > box blocks all input, thus if a terminal server sends breaks at > power down they are blocked when DTR drops first. There is a > timing issue here but it seems to work, I suspect they have a > transmission delay built in to catch the fault before the BREAK is > sent but I don't know this for sure. > > The beauty of it is that we can still use BREAK to halt the system > if we want. If the terminal server looses power all our Sun's > DON'T halt. It would also cover off any problems of the line being > cut and looking like a break as long as DTR is cut at the same > time. > > The only down side is the price tag. Indeed. Time to (again?) post the link to circuit diagram of what I believe is an equivalent device. The diagram was originally posted in sun-spots v5n45 by Malcolm Harper, back before the WWW and most copies are in compressed archives and thus not indexed by the likes of Google. A copy can now be found at this location: http://sunsite.kth.se/sun/sun-spots/v5n45.Z The relevant post has been re-copied to at least these locations subsequently: http://sunsite.bilkent.edu.tr/pub/sun-info/sunspots/v9n20 http://mail-index.netbsd.org/port-sparc/2002/05/16/0000.html -- Greg A. Woods +1 416 218-0098; <g.a.woods@ieee.org>; <woods@robohack.ca> Planix, Inc. <woods@planix.com>; VE3TCP; Secrets of the Weird <woods@weird.com>