Subject: Re: SparcStation ipx versus Sparc Classic
To: Don Yuniskis <auryn@GCI-Net.com>
From: Greg A. Woods <woods@weird.com>
List: port-sparc
Date: 05/05/2002 15:10:43
[ On Saturday, May 4, 2002 at 20:39:26 (-0700), Don Yuniskis wrote: ]
> Subject: Re: SparcStation ipx versus Sparc Classic
>
> "Greg A. Woods" <woods@weird.com> wrote:
> >
> > Well, are you not the one complaining about the problem?  Why don't you
> > try the fix -- maybe your receivers are not designed correctly....
> 
> Um, already *tried* the "fix".  Hence my previous comments that it
> "doesn't work"
> 
> As far as the "receivers"... they aren't *my* receivers, they are *Sun's*
> receivers!  The box that I have sitting in series with the *one* Classic
> that "solves" this problem has no problems with any of the "problem"
> devices being plugged/unplugged...
> 
> That, to me, lends a good deal of suspicion on where the
> "problem" lies.  :>

Heh heh....   :-)

Yes, that's exactly my point!  ;-)

> Perhaps my early experiences in this industry have me biased...
> software solutions being preferable to hardware ones (since,
> as a manufacturer, you can implement software fixes far more
> cheaply than hardware ones -- if you have an existing product
> base in the field)

Well in the case of console interrupts you really do want the lowest
possible level hardware interrupt, esp. given that the reason you might
want to interrupt the system is that it's got a bug of sorts where it's
managed to disable/ignore all device interrupts.  Other than the Big Red
Switch (which is definitely an IBM/PC euphemism!), this console
interrupt is your last resort to understanding anything of why your
system has mysteriously locked up.....  Even a serial BREAK condition is
barely suitable, and only if the system always treats console interrupts
with the utmost priority and care (and as few people as possible ever
muck with that code).

I really wish my sparcstations had at least a hardware reset switch....

> Does Sun's (original!) documentation say "whatever you plug in the console
> port must remain powered up at all times"?  Or, more likely, have they only
> acknowledged the problem after the fact -- "Ooops!  To work around this
> problem, do the following..."?

I don't know for sure, but I suspect Sun will (or did, past tense, these
being older machines) say that if you're using the serial console then
you should have it permanently connected, otherwise you should be using
it as a workstation and have at minimum a keyboard permanently
connected.  After all there's industry acknowledgement of this in the
several multi-console switches which go to considerable effort and
expense to ensure the host always sees a keyboard and mouse as present
regardless of where the operator's typing to....

> > If you put your machines all in the environment they were designed for,
> 
> And, what environment, exactly, is that?  Where have you seen this defined?
> I sure would like to see where Sun has told me what *not* to do...

Well, Sun do publish a fairly detailed and quite useful data center
design document....  :-)

> So, hard to say *they* didn't "do their best"...  I should peek inside
> one of the SPARCs to see what *their* interface looks like...

Good idea!  :-)

> (sigh... when are we going to have an Open Hardware revolution?)

I'd be happy with just an OpenFirmware implementation for common
"IBM-PC" class machines....  :-)

-- 
								Greg A. Woods

+1 416 218-0098;  <gwoods@acm.org>;  <g.a.woods@ieee.org>;  <woods@robohack.ca>
Planix, Inc. <woods@planix.com>; VE3TCP; Secrets of the Weird <woods@weird.com>