From: jmaynard@thebrain.conmicro.cx (Jay Maynard) Newsgroups: alt.folklore.computers,alt.sys.pdp10 Subject: Re: Field Service (was re: Disk array blinkenlights ...) References: <88pf5o$hgq@netaxs.com> <38B9E86F.F32B7A3C@bellatlantic.net> <1b9005rit3.fsf@viper.cs.nmsu.edu> Reply-To: jmaynard@texas.net Message-ID: User-Agent: slrn/0.9.5.4 (UNIX) Lines: 11 NNTP-Posting-Date: Mon, 28 Feb 2000 09:38:43 CST Organization: Giganews.Com - Premium News Outsourcing X-Trace: sv2-X3PmTblvVqJk392bjKIWOkS8og1gep1bKT+MJJtAN/BNZ0Z6gsyF7XEMQJ4Mb3SQgCFZXU9/BtXNihl!WUzSOk/3Ti6SSvlhwT2JLg== X-Complaints-To: abuse@GigaNews.Com X-Abuse-Info: Please be sure to forward a copy of ALL headers X-Abuse-Info: Otherwise we will be unable to process your complaint properly Date: Mon, 28 Feb 2000 15:38:43 GMT Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!newsfeed-zh.ip-plus.net!news.ip-plus.net!news.datacomm.ch!newscore.gigabell.net!newsfeed.tli.de!newsfeed.direct.ca!nntp2.giganews.com!news6.giganews.com.POSTED!jmaynard Xref: chonsp.franklin.ch alt.folklore.computers:50503 On Mon, 28 Feb 2000 14:30:09 GMT, Sarr J. Blumson wrote: >This works both ways, of course, and sometimes has to be earned. One of the >compliments I will always most treasure was when a FSE I knew introduced me >(a programmer) to a new guy saying "If he says the hardware is broken, it's >broken." Indeed. As a systems programmer, I always tried my best to isolate the exact cause of a problem for this exact reason: when I called for support, I wanted to cut through the "have you plugged it in?" layers of debugging quickly to get to the meat of the problem, and to do that, I had to earn a reputation as someone who knew what he was talking about. ###### Newsgroups: alt.folklore.computers,alt.sys.pdp10 References: <88pf5o$hgq@netaxs.com> <38B9E86F.F32B7A3C@bellatlantic.net> <1b9005rit3.fsf@viper.cs.nmsu.edu> Reply-To: sarr@umich.edu Organization: University of Michigan, College of Engineering Subject: Re: Field Service (was re: Disk array blinkenlights ...) From: sarr@engin.umich.edu (Sarr J. Blumson) Lines: 19 Message-ID: Date: Mon, 28 Feb 2000 14:30:09 GMT NNTP-Posting-Host: 207.75.146.69 X-Trace: news.itd.umich.edu 951748209 207.75.146.69 (Mon, 28 Feb 2000 09:30:09 EST) NNTP-Posting-Date: Mon, 28 Feb 2000 09:30:09 EST Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!newsfeed-zh.ip-plus.net!news.ip-plus.net!News.Amsterdam.UnisourceCS!skynet.be!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsxfer3.itd.umich.edu!news.itd.umich.edu!sarr Xref: chonsp.franklin.ch alt.folklore.computers:50565 In article , Brian Inglis wrote: > >OTOH, most DEC FS staff I met were competent and confident enough >to listen to what our staff told them, and check out parts we >suggested might be a problem, before going the full system >exerciser route. This works both ways, of course, and sometimes has to be earned. One of the compliments I will always most treasure was when a FSE I knew introduced me (a programmer) to a new guy saying "If he says the hardware is broken, it's broken." -- -------- Sarr Blumson sarr@umich.edu voice: +1 734 764 0253 home: +1 734 665 9591 ITD, University of Michigan http://www-personal.umich.edu/~sarr/ 519 W William, Ann Arbor, MI 48103-4943 ###### From: "Charlie Gibbs" Newsgroups: alt.folklore.computers Subject: Re: Field Service (was re: Disk array blinkenlights ...) Date: 29 Feb 00 11:15:55 -0800 Organization: http://extra.newsguy.com Lines: 36 Message-ID: <1684.94T2775T6756180@sky.bus.com> References: <88pf5o$hgq@netaxs.com> <38B9E86F.F32B7A3C@bellatlantic.net> <1b9005rit3.fsf@viper.cs.nmsu.edu> NNTP-Posting-Host: p-102.newsdawg.com X-Newsreader: THOR 2.5a (Amiga;TCP/IP) Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!newsfeeds.belnet.be!news.belnet.be!newsfeed.icl.net!newsfeed.icl.net!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.berkeley.edu!pln-w!spln!extra.newsguy.com!newsp.newsguy.com!news2 Xref: chonsp.franklin.ch alt.folklore.computers:50715 In article jmaynard@thebrain.conmicro.cx (Jay Maynard) writes: >On Mon, 28 Feb 2000 14:30:09 GMT, Sarr J. Blumson > wrote: > >>This works both ways, of course, and sometimes has to be earned. One >>of the compliments I will always most treasure was when a FSE I knew >>introduced me (a programmer) to a new guy saying "If he says the >>hardware is broken, it's broken." > >Indeed. As a systems programmer, I always tried my best to isolate >the exact cause of a problem for this exact reason: when I called for >support, I wanted to cut through the "have you plugged it in?" layers >of debugging quickly to get to the meat of the problem, and to do that, >I had to earn a reputation as someone who knew what he was talking >about. True enough. One day a timing belt broke in our Univac 9300's card reader. I called field service, and they started into what was going to be a tedious procedure of "what does the belt look like, where is it in the machine", etc. I cut that short by saying, "I have the parts diagram here..." I had dug out the appropriate service manual beforehand, and read them the part number of the broken belt. You could hear the CE light up over the phone. In the meantime we couldn't do anything anyway, so I took a lot of rubber bands, wrapped them around the pulleys in place of the broken belt, and tried to fire up the card reader. It took a couple of seconds for everything to come up to speed, but with a bit of care I was able to keep the machine in production until the CE arrived. -- cgibbs@sky.bus.com (Charlie Gibbs) Remove the first period after the "at" sign to reply. ###### From: prs@gol.com (Jacqui or (maybe) Pete) Newsgroups: alt.folklore.computers Subject: Re: Field Service (was re: Disk array blinkenlights ...) Message-ID: <38c0e4dd.1823680@nnrp.gol.com> References: <88pf5o$hgq@netaxs.com> <38B9E86F.F32B7A3C@bellatlantic.net> <1b9005rit3.fsf@viper.cs.nmsu.edu> X-Newsreader: Forte Agent 1.5/32.451 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 25 Date: Thu, 02 Mar 2000 22:06:39 GMT NNTP-Posting-Host: 203.216.43.153 X-Complaints-To: abuse@gol.com X-Trace: nnrp.gol.com 952034799 203.216.43.153 (Fri, 03 Mar 2000 07:06:39 JST) NNTP-Posting-Date: Fri, 03 Mar 2000 07:06:39 JST Organization: Global Online Japan Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!isdnet!newspump.monmouth.com!newspeer.monmouth.com!newsfeed.gol.com!203.216.70.8.MISMATCH!nnrp.gol.com.POSTED!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:50953 On Mon, 28 Feb 2000 15:38:43 GMT, jmaynard@thebrain.conmicro.cx (Jay Maynard) wrote: >On Mon, 28 Feb 2000 14:30:09 GMT, Sarr J. Blumson wrote: >>This works both ways, of course, and sometimes has to be earned. One of the >>compliments I will always most treasure was when a FSE I knew introduced me >>(a programmer) to a new guy saying "If he says the hardware is broken, it's >>broken." > >Indeed. As a systems programmer, I always tried my best to isolate the exact >cause of a problem for this exact reason: when I called for support, I >wanted to cut through the "have you plugged it in?" layers of debugging >quickly to get to the meat of the problem, and to do that, I had to earn a >reputation as someone who knew what he was talking about. I remember once when the development HP250 was dead on boot-up. I figured I knew what the problem was & crawled round the back, checked the power (OK) & then re-set whatever it was (I forget). No dice. So I called FS. And they came and found that the *only* problem with the machine was that it was unplugged. I'd fixed the problem, but then kicked the plug out of the wall getting back out from under the beast. But I didn't even try explaining that. ###### From: "Simo Tuominen" Newsgroups: alt.folklore.computers Subject: Re: field/frame, was: Re: video tape backup systems Date: Fri, 10 Mar 2000 22:37:47 +0200 Organization: Heinrich Heine Universitaet Duesseldorf Lines: 12 Message-ID: <8ai0v1$ogu@poseidon.rz.uni-duesseldorf.de> References: <89v5an$ehl$1@freenet9.carleton.ca> <38C3F59B.1913@azstarnet.com> <38cb545f.6488407@news.freeuk.net> <9o6ecsgabhr97fdodsvhq2c5nj7t9eemks@4ax.com> <8a7cno$fvr$1@panix6.panix.com> <8aa6sa$p41@poseidon.rz.uni-duesseldorf.de> <8aafml$a4m$1@unlisys.unlisys.net> NNTP-Posting-Host: lan1.miu.uni-duesseldorf.de X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 5.00.2919.6600 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2919.6600 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!newscore.univie.ac.at!194.25.134.126.MISMATCH!newsfeed01.sul.t-online.de!t-online.de!uucp.muenster.de!news-koe1.dfn.de!RRZ.Uni-Koeln.DE!news.rz.uni-duesseldorf.de!usenet Xref: chonsp.franklin.ch alt.folklore.computers:51852 "Wolfgang Schwanke" wrote in message news:8aafml$a4m$1@unlisys.unlisys.net... [snip] > between the two, and has lead many people to believe that > VCRs drop scan lines on purpose, which of course is a compolete > misunderstanding. I didn't say that the loss is based on some arbitrary decision. I know very well that it just happens, because tecnology isn't perfect. ###### Sender: Ian Stirling From: Ian Stirling Subject: Re: field/frame, was: Re: video tape backup systems Newsgroups: alt.folklore.computers References: <89v5an$ehl$1@freenet9.carleton.ca> <38C3F59B.1913@azstarnet.com> <38cb545f.6488407@news.freeuk.net> <9o6ecsgabhr97fdodsvhq2c5nj7t9eemks@4ax.com> <8a7cno$fvr$1@panix6.panix.com> <8aa6sa$p41@poseidon.rz.uni-duesseldorf.de> <8aafml$a4m$1@unlisys.unlisys.net> <8ai0v1$ogu@poseidon.rz.uni-duesseldorf.de> Organization: None.. User-Agent: tin/pre-1.4-980818 ("Laura") (UNIX) (Linux/2.2.13 (i586)) Lines: 27 Message-ID: <9tcz4.434$b8.113641@news4.usenetserver.com> X-Abuse-Info: Please be sure to forward a copy of ALL headers X-Abuse-Info: Otherwise we will be unable to process your complaint properly X-Complaints-To: admin@usenetserver.com NNTP-Posting-Date: Mon, 13 Mar 2000 15:47:01 EST Date: Mon, 13 Mar 2000 20:47:01 GMT Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!feed2.news.luth.se!luth.se!newsfeed1.uni2.dk!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!cyclone1.usenetserver.com!cyclone1.usenetserver.com!news4.usenetserver.com.POSTED!not-for-mail Xref: chonsp.franklin.ch alt.folklore.computers:51832 Simo Tuominen wrote: >"Wolfgang Schwanke" wrote in message >news:8aafml$a4m$1@unlisys.unlisys.net... >[snip] >> between the two, and has lead many people to believe that >> VCRs drop scan lines on purpose, which of course is a compolete >> misunderstanding. >I didn't say that the loss is based on some arbitrary decision. I know >very well that it just happens, because tecnology isn't perfect. I think the point Wolfgang was trying to make, is that it doesn't happen. VCR's (at least VHS/betamax) record all the lines of every frame. The only reason picture quality is comparatively poor is the low horizontal resolution. -- http://inquisitor.i.am/ | mailto:inquisitor@i.am | Ian Stirling. ---------------------------+-------------------------+-------------------------- Pieces of eight! Pieces of eight! Pieces of eight! Pieces of eight! Pieces of eight! Pieces of nine! ###### From: nailed_barnacleSPAMFREE@hotmail.com (barnacle) Newsgroups: alt.folklore.computers Subject: Re: field/frame, was: Re: video tape backup systems Date: Tue, 14 Mar 2000 10:12:12 GMT Organization: Easynet Group plc Lines: 67 Message-ID: <8al3gn$t1i$1@quince.news.easynet.net> References: <89v5an$ehl$1@freenet9.carleton.ca> <38C3F59B.1913@azstarnet.com> <38cb545f.6488407@news.freeuk.net> <9o6ecsgabhr97fdodsvhq2c5nj7t9eemks@4ax.com> <8a7cno$fvr$1@panix6.panix.com> <8aa6sa$p41@poseidon.rz.uni-duesseldorf.de> <8aafml$a4m$1@unlisys.unlisys.net> <8ai0v1$ogu@poseidon.rz.uni-duesseldorf.de> <9tcz4.434$b8.113641@news4.usenetserver.com> NNTP-Posting-Host: nbarnes.easynet.co.uk X-Trace: quince.news.easynet.net 953028951 29746 194.154.98.206 (14 Mar 2000 10:15:51 GMT) X-Complaints-To: abuse@easynet.net NNTP-Posting-Date: 14 Mar 2000 10:15:51 GMT X-Newsreader: News Xpress 2.01 Path: chonsp.franklin.ch!pfaff.ethz.ch!news-zh.switch.ch!news-ge.switch.ch!news-fra1.dfn.de!news0.de.colt.net!colt.net!newspeer.clara.net!news.clara.net!news-hub.cableinet.net!easynet-tele!easynet.net!quince.news.easynet.net!egbert Xref: chonsp.franklin.ch alt.folklore.computers:51923 In article <9tcz4.434$b8.113641@news4.usenetserver.com>, Ian Stirling wrote: >Simo Tuominen wrote: > >>"Wolfgang Schwanke" wrote in message >>news:8aafml$a4m$1@unlisys.unlisys.net... >>[snip] >>> between the two, and has lead many people to believe that >>> VCRs drop scan lines on purpose, which of course is a compolete >>> misunderstanding. > >>I didn't say that the loss is based on some arbitrary decision. I know >>very well that it just happens, because tecnology isn't perfect. > >I think the point Wolfgang was trying to make, is that it doesn't happen. >VCR's (at least VHS/betamax) record all the lines of every frame. >The only reason picture quality is comparatively poor is the low horizontal >resolution. > There are problems with VCRs but as Wolf said, they record everything that comes at them. You get an output of two fields for each frame, either 25 or 30 times a second. However, you may actually get worse results with better recorders... Time base complicators^h^h^h^hcorrectors clock sample replay video at a variable rate and clock it out at a constant rate. This works well on broadcast pictures but on digital data you'd be replacing slow jitter with fast jitter which might be a problem depending on your coding scheme. (try displaying teletext or on-screen displays over a video replay to see how bad the lf jitter is!) Drop-out compensators are worse - they work by noting the absence of RF from the head where the recording is missing and copy in either part or all of a previous line. The colour-under modulation system may decide that an edge with spectrum somewhere round 4.43Mhz (or the NTSC equivalent) is actually colour information and will code it a low frequency narrow bandwidth sub-carrier...losing all sorts of phase and timing info when it gets put back together. The colour decoding circuits will knock a great big notch in the input video where the subcarrier lives...hopefully this is outside the frequency band you're interested in but it depends how good the filters are. You also don't know quite what the pal/ntsc coder is going to do when it puts the signal back together. A machine with half speed/full speed should have full width heads and half width heads, selected depending on tape speed...if you have a cheapie machine, the same head is probably used for both so the guard band between adjacent tracks is enormous...but sadly the noise is worse. However, if we assume a bandwidth of 2.5MHz but an available picture time of 80%, that leaves 2MHz. If the noise floor is say -30dB (not too bad for vhs...) that nice Mr Shannon says we can have around 10Mbits/second maximum...which is 100Gb per hour...say 12GBytes per hour. Not bad for ancient technology! Of course, this is all completely bollixed up when you use digital recording with mpeg compression on the video... -- barnacle http://www.nailed-barnacle.co.uk