OK, I know this is a silly question, and not even much related to DSP... They say you shouldnt leave A VHS cassette on pause for a long time, because it damages the read-head. Similarly, you should use a moving screen saver on a monitor, because a static image can impair the screen... On this note I have two questions... 1. Is it bad for a DVD player to be left on pause for a long time 2. If you are using a debugging tool on a computer program, is it bad for the computer if you wander off mid-debug and leave the programme hanging mid run for a long time.
Silly Question about "movement"
Started by ●April 16, 2004
Reply by ●April 16, 20042004-04-16
porterboy76@yahoo.com (porterboy) wrote in message news:<c4b57fd0.0404152342.55e35c46@posting.google.com>...> OK, I know this is a silly question, and not even much related to > DSP... > > They say you shouldnt leave A VHS cassette on pause for a long time, > because it damages the read-head.I think that happens because the read-head is spinning and in contact with the tape. There is a mechanical wear on the read-head.> Similarly, you should use a moving > screen saver on a monitor, because a static image can impair the > screen...That's because in CRTs, the glow of the phosphor(?) coating causes it to wear down. Displaying one static image for a long time would cause the coating to mechanically wear down unevenly. Does anyone know if anything similar happens with the new flat screens? Are those LCDs?> On this note I have two questions... > 1. Is it bad for a DVD player to be left on pause for a long timeIf the disc keep spinning, then leaving it on pause would cause unnecessary wear on the moving mechanics. If the thing stops, there is no reason why leaving it should be bad.> 2. If you are using a debugging tool on a computer program, is it bad > for the computer if you wander off mid-debug and leave the programme > hanging mid run for a long time.In principle, no. There is no mechanical parts that are running, so there is no wear on the equipment. Rune
Reply by ●April 16, 20042004-04-16
porterboy76@yahoo.com (porterboy) wrote in message news:> OK, I know this is a silly question, and not even much related to > DSP...I don't know if there's such a thing as a silly question, but I do know there are questions that are off-topic. This appears to be the case here ... :-)> They say you shouldnt leave A VHS cassette on pause for a long time, > because it damages the read-head. Similarly, you should use a moving > screen saver on a monitor, because a static image can impair the > screen...Yep. In the first case the head keeps spinning and wears off the tape. The second scenario causes the particles to be imprinted with the image if you leave it on for too long...> On this note I have two questions... > 1. Is it bad for a DVD player to be left on pause for a long timeI doubt it. There is no contact between the medium and the read mechanism, so there is no abrasion. Also, I assume the player would store the static image in RAM anyway and switch off the drive when it's not used, so I'd say it is not bad.> 2. If you are using a debugging tool on a computer program, is it bad > for the computer if you wander off mid-debug and leave the programme > hanging mid run for a long time.Generally no. If you're not interrupting something low-level that will cause a mechanical problem or some uninitialized interface weirdness this should not be harmful. It might be that the CPU load stays high while you're away, which can cause the CPU to heat up, but that should not be worse than the load inflicted on it when you do "normal" work. --smb
Reply by ●April 16, 20042004-04-16
Rune Allnor wrote:> porterboy76@yahoo.com (porterboy) wrote in message news:<c4b57fd0.0404152342.55e35c46@posting.google.com>... > >>OK, I know this is a silly question, and not even much related to >>DSP... >> >>They say you shouldnt leave A VHS cassette on pause for a long time, >>because it damages the read-head. > > > I think that happens because the read-head is spinning and in contact > with the tape. There is a mechanical wear on the read-head.But the read head is always spinning against the tape. Spiral scan and all that. Maybe it's just a myth.>>Similarly, you should use a moving >>screen saver on a monitor, because a static image can impair the >>screen... > > > That's because in CRTs, the glow of the phosphor(?) coating causes > it to wear down. Displaying one static image for a long time would > cause the coating to mechanically wear down unevenly.Burning an image into a screen is mostly a problem with monochrome monitors. I've seen an image burned into a color screen that was on 24 hours a day in a supermarket, but not lately. Is seems that something about the shadow mask relieves the problem. I use an all-black screen as a screen saver. That's both perfect and static. So there!> Does anyone know if anything similar happens with the new flat screens? > Are those LCDs?Some, not all.>>On this note I have two questions... >>1. Is it bad for a DVD player to be left on pause for a long time > > > If the disc keep spinning, then leaving it on pause would cause > unnecessary wear on the moving mechanics. If the thing stops, there > is no reason why leaving it should be bad.The same could be said about the hard disks in computers. It's not a severe problem in practice.>>2. If you are using a debugging tool on a computer program, is it bad >>for the computer if you wander off mid-debug and leave the programme >>hanging mid run for a long time. > > > In principle, no. There is no mechanical parts that are running, > so there is no wear on the equipment. > > RuneJerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●April 16, 20042004-04-16
"Jerry Avins" <jya@ieee.org> wrote in message news:4080026d$0$16448$61fed72c@news.rcn.com...> Rune Allnor wrote: > > > porterboy76@yahoo.com (porterboy) wrote in messagenews:<c4b57fd0.0404152342.55e35c46@posting.google.com>...> > > >>OK, I know this is a silly question, and not even much related to > >>DSP... > >> > >>They say you shouldnt leave A VHS cassette on pause for a long time, > >>because it damages the read-head. > > > > > > I think that happens because the read-head is spinning and in contact > > with the tape. There is a mechanical wear on the read-head. > > But the read head is always spinning against the tape. Spiral scan and > all that. Maybe it's just a myth.But when the tape is paused, all of the wear is in just one place on the tape. While this is obviously bad for the tape, I also think the head wears faster since the heat is not being carried away by a moving tape. Also as the tape heats up, the oxide probably comes off of the tape at an increased rate and plugs the heads' gaps faster than normal.> > >>Similarly, you should use a moving > >>screen saver on a monitor, because a static image can impair the > >>screen... > > > > > > That's because in CRTs, the glow of the phosphor(?) coating causes > > it to wear down. Displaying one static image for a long time would > > cause the coating to mechanically wear down unevenly. > > Burning an image into a screen is mostly a problem with monochrome > monitors. I've seen an image burned into a color screen that was on 24 > hours a day in a supermarket, but not lately. Is seems that something > about the shadow mask relieves the problem. I use an all-black screen as > a screen saver. That's both perfect and static. So there!Some wide screen TVs have a problem when showing programs with different aspect ratios. If parts of the screen are often left dark in a consistant mannor, these areas will eventually become noticeable. Of course my TV is a quaint 4/3 ratio version, so I haven't noticed this effect directly. But when I see wide screen TVs in the store, a lot of them have horizontally stretched images (very irratating to look at by the way) in what I think is an attempt to not have blank areas on the sides of the screen. My 2 cents worth. Clay
Reply by ●April 16, 20042004-04-16
Clay S. Turner wrote: ...> But when the tape is paused, all of the wear is in just one place on the > tape. While this is obviously bad for the tape, I also think the head wears > faster since the heat is not being carried away by a moving tape. Also as > the tape heats up, the oxide probably comes off of the tape at an increased > rate and plugs the heads' gaps faster than normal.All true and likely important. Be aware, though, that the polished head cylinder acts like an air bearing. Just as the head in a Winchester disk flies just above the surface (should it touch, that's a "crash"), the tape in a well designed VCR is intended to rise off the head when it's turning. Jerry -- Engineering is the art of making what you want from things you can get. �����������������������������������������������������������������������
Reply by ●April 16, 20042004-04-16
"Rune Allnor" <allnor@tele.ntnu.no> wrote in message news:f56893ae.0404160510.32d9e39d@posting.google.com...> porterboy76@yahoo.com (porterboy) wrote in messagenews:<c4b57fd0.0404152342.55e35c46@posting.google.com>...> > OK, I know this is a silly question, and not even much related to > > DSP... > > > > They say you shouldnt leave A VHS cassette on pause for a long time, > > because it damages the read-head. > > I think that happens because the read-head is spinning and in contact > with the tape. There is a mechanical wear on the read-head.On all the VCR's I've owned, the machine goes from pause to stop (no longer spinning) after a few minutes, so it doesn't allow you to forget and leave it on for hours/days and damage anything.> > On this note I have two questions... > > 1. Is it bad for a DVD player to be left on pause for a long time > > If the disc keep spinning, then leaving it on pause would cause > unnecessary wear on the moving mechanics. If the thing stops, there > is no reason why leaving it should be bad.But if your TV is on and displaying the image, you could be burning the image in! Nice how that ties in to the above question. Some DVD players automatically dim the image after it has been paused for a certain time, presumably to prevent this.
Reply by ●April 16, 20042004-04-16
On 16 Apr 2004 08:48:42 -0700, stephan.bernsee@web.de (Stephan M. Bernsee) wrote: (snipped)> >I don't know if there's such a thing as a silly question, but I do >know there are questions that are off-topic. This appears to be the >case here ... :-)yes, your right. It's off-topic. But that's the fantastic (phantastisch) thing about this newsgroup. These guys can answer almost any reasonable question. Some time ago I asked the *very off-topic* question, "Is it safe to eat the food contained in a dented metal can?" In different words, "If a can of food is dented, should I throw the can away?" Ya' know what? The guys here gave me all sorts of good advice with regard to dented food cans. This newsgroup is a blessing. [-Rick-]
Reply by ●April 17, 20042004-04-17
You can say that again, Rick! I too learned to appreciate the advice given here over the past years... (you may remember me as Stephan Sprenger)... ;-) Cheers, Stephan r.lyons@_BOGUS_ieee.org (Rick Lyons) wrote in message news> > (snipped) > Ya' know what? The guys here gave me all sorts > of good advice with regard to dented food cans. > > This newsgroup is a blessing. > > [-Rick-]
Reply by ●April 17, 20042004-04-17
porterboy76@yahoo.com (porterboy) wrote in message news:<c4b57fd0.0404152342.55e35c46@posting.google.com>...> OK, I know this is a silly question, and not even much related to > DSP... > > They say you shouldnt leave A VHS cassette on pause for a long time, > because it damages the read-head. Similarly, you should use a moving > screen saver on a monitor, because a static image can impair the > screen...Not an issue on moderns screens - nowadays people use savers for primitive privacy while they are away from their desk.> > On this note I have two questions... > 1. Is it bad for a DVD player to be left on pause for a long time > 2. If you are using a debugging tool on a computer program, is it bad > for the computer if you wander off mid-debug and leave the programme > hanging mid run for a long time.Hmm, the biggest issue is that someone may press a few keys on your behalf while you are away...
