Xref: utzoo comp.os.os2:1092 comp.sys.ibm.pc:46123 comp.windows.ms:1683
Path: utzoo!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!uunet!wang!wdr
From: wdr@wang.com (William Ricker)
Newsgroups: comp.os.os2,comp.sys.ibm.pc,comp.windows.ms
Subject: Re: Popping noise in switching windows (-> comp.sys.ibm.pc)
Message-ID: <1990Mar9.142408.13018@wang.com>
Date: 9 Mar 90 14:24:08 GMT
References: <DKB.90Mar5152839@anquetil.cs.brown.edu> <-283389995@hpcupt1.HP.COM>
Organization: Wang Labs, Lowell MA, USA
Lines: 48

swh@hpcupt1.HP.COM (Steve Harrold) writes:

] Re: Popping noise on screen 

] >>> How come when I switch back and forth with Alt-Esc among my sessions,
] >>> when I end up in my Dos box I hear a little popping noise from my
] >>> 8513 screen?  This has happened pretty consistently since I got this
] >>> PS/2-70 (last August).  Is this indicative of a problem?

] I, too, have noticed a small popping noise on some occasions, but not
] in the environment mentioned.

] It happens to me (sometimes) under DOS when the screen content undergoes
] a dramatic change, say from a full screen editor in graphics mode, switching
] back to the plain DOS prompt.  This has occurred with EGA and VGA monitors.

] This has gone on for a couple of years without any apparent damage to
] anything (except my peace of mind).

] I would be very pleased to know what electronic/mechanical phenomenon is
] going on.

I've noticed this with popup applications and other programs that toggle
screen background intensity, as well as OS/2 to the (usually black) 
Chernobyl Box.  It is not unique to PS/2s; our Wang monitors and various
other systems I've used have made little noises on screen transitions too.
I don't recall if it only occurs on large color monitors or not; they are
what I associate the phenomenon with.  (I don't still have the Compaq 
portable with plasma display; it would be an interesting data point.)
    I've always assumed it was static discharge/Collapse,  resulting 
from the  sudden drop in the flow of "current" (static charge  
continually deposited by electron beam, and discharged to atmosphere 
or  your hand).  I'd rather believe it was the static I feel when 
dusting the screen, and not something internal in the tube's beam-guide 
coils.  Since the painted area sometimes also bounces on program 
transitions -- when the VGA card is re-configured, or OS/2 downshifts 
to real-mode -- it could be something nasty, I suppose.

I've added comp.sys.ibm.pc and comp.windows.ms, as they're more likely to
have answers for us.  (Which is why I cheated on the >> chars, so they
could see what we're talking about, and maybe help.)

Bill Ricker wdr@wang.com or wricker@northeastern.edu


(-: Why do they call the Dox3xBox the Chernobyl Box?
    Because microsoft keeps pouring concrete around it, hoping the nasty
    standard-apps won't leak out anymore. :-)