test-drb June 2006

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One For The Apple Guys

by Billy.Pettit＠wdc.com

eBay: 7628399735

18 years, 6 months

VT100 keyboard -> PS2?

by waisun.chia＠gmail.com

Has anybody interfaced a VT100 keyboard (1/4 plug) to a modern PeeCee? This either via a PS/2 or USB interface...

18 years, 6 months

by Billy.Pettit＠wdc.com

Mike wrote: I just finished reviewing a few cases sent out for servicing. One laptop was reported as not booting, - the tech toggled the display -it had been set to use external monitor. Another laptop was frozen, it did not respond to crtl-alt-del - the tech held in the power button, it was hibernating. ----------------------------------- Billy: I've been buying broken iPods minis on eBay for work. One I got was described as unable to load songs or use the menu. Cost a whole twenty dollars. I found the Hold switch in lockout. Only visible switch and dispalys red when on. Toggled the switch and had an iPod in perfect working condition with a good battery. More than made up for some of the junkers I get and have to fix. Billy

18 years, 6 months

Docs avail: Vermont Research Model 1016 Drum Memory (1969)

by dave06a＠dunfield.com

Yesterday I was given a fairly hefty documentation set: Installation and Operation Model 1016 Drum Memory with Digital Interface Vermont Reserch Corporation North Springfield, Vermont Most of the documents are dated 1969. It contains a lot of technical information, theory of operation all all the boards, full schematics, copies of the original blueprint drawings etc. Anyone need/looking-for this? Regards, Dave PS: Anyone know what type of system this was used with? -- dave06a (at) Dave Dunfield dunfield (dot) Firmware development services & tools: www.dunfield.com com Collector of vintage computing equipment: http://www.classiccmp.org/dunfield/index.html

18 years, 6 months

by Billy.Pettit＠wdc.com

Teo Zenios wrote: Any how many hard drive companies are actually making a profit moving those 376 Million units? I don't expect blueprints and electrical schematics with the electronics I buy. But I do expect some way of finding out if the hardware is actually broken or something else (software, bad inputs etc) is causing things to not work. What percentage of returned electronics are sent back 100% working because people didn't have a good way to troubleshoot what the real problem was in the system? TZ ------------------------------------------------------------------ Billy: I believe that there are six major companies still doing disk drives: Seagate, Hitachi, Toshiba, Fujitsu, WD and Samsung. Seagate is doing great, WD about half of Seagate's profit. Samsung, and Fujitsu are profitable. Toshiba, probably not and Hitachi definitely not. If you are looking into testing units, look for the SMART attributes. Most modern drives do elaborate error monitoring and logging. These values are available to the user by reading out the SMART logs. Some OS's do this as a matter of course and even present error messages when a drive is starting to fail. Finally, recent drives usually have Drive Self Test capability if you want to invoke diagnostics. The ARM cores used have tremendous potential and power. An ARM- 9 processor at 400 MHz is far more powerful than any of the supercomputers I worked on. And they reserve10-20GBs for maintenance use - many times more drive capacity than any of the supercomputers I used to maintain. No Fault Found on returns can vary from 20 to 50%. That is the same ratio it was 30 years ago. And not surprisingly, it is the same ratio for Optical drives, game machines, printers, etc. It is not so much not able to troubleshoot as the fact that when a system goes in for repair, they usually swap out a hard drive. When that doesn't fix the issue, the techs don't put the original drive back. On all electronics, there are many user influenced errors that can never be reproduced. Static is one; power failures, partially plugged in sockets, shock, vibration from the environment, noisy AC power, and on and on. There are a large number of external conditions that can cause equipment failure. If you are not there, you don't know what the conditions are. Of course there is the other extreme. I worked on a computer once that the building contractor had tied the lightning rod to the grounding plane of the computer room. Every single PCB in the system was fried. I saw an IPod recently that had been run over by a bull dozer. We often get calls about recovering data from laptops dropped into a lake or the ocean. I have the case of an XBox that had been hit with a sledge hammer by a frustrated wife. Optical is usually sent in for foreign material in the disk tray. On the game machines that I gathered stats on, the number one failure was 2 or more CDs. The users thought they could stack up games like a phonograph. And I thought finding pizza in a DVD was bizarre until I checked the logs and found we averaged one of two a week. I guess a game system is warm and lends itself to being an oven. Billy

18 years, 6 months

by Billy.Pettit＠wdc.com

Tony Duell wrote: Well, if I've got a few hundred megs of data on a hard drive, I'd rather repair a simple electronic fault than have to restore it all from backups. And it would take me lest time to repair such a fault than it would take to ship the replacement drive. -Tony ------------------------------------ Billy - I'll try one last time and then give up. Tony, hard drives rarely rarely have a simple electronic fault. The ratio of mechanical to electrical faults is around 98 to 1. They are so rare that most companies don't repair PCBs. You cannot repair mechanical failures in drives made in the last 25 years without highly specialized equipment. Drives made in the last ten years require Class 10 clean rooms, thanks to flying heights less than the wavelength of visible light. Yes I know you have a few early primitive drives that you fixed in the past. But technology has moved a long long ways from those Paleolithic days. We still repair drives, we still use technicians, but they sure as hell don't use soldering irons, oscilloscopes and schematics. And no, we didn't lose any customers because we stopped providing maintenance manuals. The demand for disk drives soared last year to 376 million units, a 23% jump over the previous year. I know you didn't buy any, and we'll have deal with that loss. But out of the tens of millions we sell every quarter, not a single paying customer asks for documentation other than spec sheets and the fluff manual that is standard today. And none of those customers have the slightest interest in any kind of repair. So tell me - why in the hell should we do something as pointless as provide documentation that will go unused? If you want to influence that SOP, buy some new product and demonstrate the need. Exercise your power by purchase. Otherwise, accept that the rest of the world doesn't like nor want equipment that requires repair. And please stop complaining about the lack of manuals. They ain't gonna happen. The products you like to work on were obsolete before most of our engineers were born. The world isn't going to back up to meet your needs. So why don't you develop new skills and learn how to repair this new equipment? Expand and learn - a lot of us here are older than you and had no trouble adapting to technological change. If you insist on only using trivial Stone Age technology, it's your choice. But you're missing out on equipment many times more exciting and fun to use. There's a place for you at the cutting edge. And you can still have your toys; have your cake and eat it too. And if not, well we'll miss you. Billy

18 years, 6 months

classiccmp todo/idea list

by vp＠drexel.edu

"Jay West" <jwest at classiccmp.org> wrote: > If you've got one in front of you, why do you need pictures of the inside? to answer questions like: does this bracket do this way or that way? also was that placed like that on purpose? Some machines (esp old ones) have been modified and you may want to bring it back to its nominal state (esp if you are investigating some strange behaviour). Another example is the 9825A where a flat cable does not follow the convention that the red stripe should be near side of the connector with the little triangle. On a machine with voltages ranging from -20 to +20 you'd better plug in stuff the right way. Having said that, I usually take pictures of the machine as I take it apart to make sure I can go back and check things. In the case of the 9825A I assumed that having the service manual (original with readable photos) would be sufficient. False! I had to check the location of the ground connections to be sure that the connector was going in the "wrong" way (red stripe away from the triangle). In fact the same flat cable plugs in the other way round (red stripe near the triangle) to the I/O connector, which leads me to believe that HP people at the time either ignored or were unaware of this convention. **vp

18 years, 6 months

Need pointers on Oscilloscopes

by joachim.thiemann＠gmail.com

If the OP is looking for a new scope that's cheap, here at McGill, we've been using the PicoScope USB scopes in the EE labs (DSP Hardware). We trust undergrads with them, and they're a heck of a lot easier to store (if you have 10 of them in a lab). No knobs or buttons, just 2 BNC and a USB-B on a white box the size of a hardback book. Unfortuantely they are Windows-only, so no use for someone like me who's only got Mac and NetBSD at home. And it's quite possible to find a good used analog scope for less, I think, but a digital storage scope has some advantages... Joe.

18 years, 6 months

by Billy.Pettit＠wdc.com

Tony Duell wrote: > single board drives, we didn't want them to repair the units. The = No, you'd rather sell them a replacement drive than have them replace some $1 component (I've seen a Wren, there's a lot that can be field-repaired on one, expecially given a schematic). ---------------------------------------------------------------------------- ---- Billy: Once again you missed the point. Sure there's a few items on Wren that could be repaired. Though in all the hundreds of thousands built, I never saw a single PCB failure. And I wish you would consider your time as valuable. Repair, as you said earlier, is not about the 10P resistor but about the knowledge and experience of the technician. It is not free. Maybe everybody, could fix it without damaging it. But if they didn't, then the manufacturer is liable for the botched repair. And don't say this didn't happen. For almost 10 years, those of us in Field Service had to go out and clean up the messes that so called trained engineers created. I have enough stories about the idiocy prevalent in the computer repair field, that I've started writing a book about some of them. We did not want to cater to this tiny miserable bunch that caused so much grief and expense, so we forced a change. And it became a standard for peripheral companies. Eliminating maintenance and repair on hard drives saved tens of millions of dollars and raised our customer satisfaction enormously. The main point is: to accommodate the whimsy of one hobbyist, we would have had to invest 100's of thousands of dollars in technical manuals, keep them up to date, make them available. The Wren had more than 50 variations - I know because I had to track them. It would have required a staff of 20 to keep the manuals accurate. Making a maintenance manual available would have been a disastrous financial mistake. And for what purpose? Only one person in the world would use this documentation. Everyone else would prefer to spend the $50 on a new drive than risk reusing a repaired one Billy.

18 years, 6 months

Docs avail: Vermont Research Model 1016 Drum Memory (1969)

by Billy.Pettit＠wdc.com

Chuck Guzis wrote: On 6/8/2006 at 7:59 PM Billy Pettit wrote: >Billy: >There were several reasons, but the biggest one was: they could do parallel >read and writes. You could stripe them for 16 bit wide data paths that >became incredibly fast. And with virtually no bit skew. Plus access time >was never more than one revolution. Yeah, but in a Star-100 SBU, there was enough memory in the thing that the drum hardly got used past booting the thing up. There was just no point to the speed. The Star paged to disk; there were some plans initially for a huge drum, running something like 512 bits parallel, but I don't know if the concept ever made it off paper. The funny thing was that there were the same SBUs on the two Star-1B's in Sunnyvale--the SBU's were qutie a bit faster than the 1Bs themselves. (Those two systems eventually went into the dumpster per company policy). During the 60's, drums gave disks a run for their money. I remember a Univac 1108 with the very large FASTRAND-II moving-head drum on it. There were a number of late 50's-early-60's machine with drum as the main memory, such as the IBM 650 and the LGP-30. "one plus one" addressing. Cheers, Chuck ---------------------------------------------------------- Billy: What a meaty message! All sorts of hooks. I'll try to stay in order. 1. The Star-100 was massive. And memory technology was in a transition, so a lot of the plans changed mid-stream. That was part of what killed it. By time it was working, it was obsolete. The storage concept came from 7600 ideas. You are dead on with the word staging. What software wanted was to stage ALL data transfers. The program would be loaded (including all required data tapes) from a tape station. In turn, the tape station would send the package to the storage station via memory to memory transfer. Then the storage station would transfer to the main memory also via memory to memory. Except that this transfer was supposed to be via 512 bit SWords(SuperWords). It was sort of the ultimate of Seymour's philosophy of using the CPU for calculating and every thing else was done off line. 2. The drum was an interim device. There was a point to it - the speed was needed to debug the channels and the streaming busses. This program required a lot of band aids while waiting for the new technology to come along. It made a lot of risky bets on new peripherals to keep up with the speed. The 512 bit wide drum did get to the prototype stage. But it was incredibly costly. To get the bit density and performance needed, the entire drum was filled with Helium under pressure. But it was fast. If I remember the analysis correctly, the big drum would have cost more than the main frame. 3. The disks were never close to what was needed. Cray was using Ibis and Fujitsu disk with parallel heads (4 bits at a time). The Star team funded a parallel head disk from Normandale, but I don't it ever got of the ground either. They also had a multiple actuator drive in the lab that had the same problems that caused all other attempts of this idea to fail. 4. The most exotic peripheral I saw was an 18" wide tape unit that used a helical scan head bar. It was being developed by the Government Systems Division. It made so much noise that you had to be in another room when it was running. 5. So there were all sorts of experiments running side by side to find some way to support the huge data rate required. The drums were more a proof of concept. They allowed the channels to run at full speed even if they couldn't supply much data. 6. The Star-1Bs were never intended to be products or peripheral stations. They were a totally microcoded pseudo-processor. Again, they were proof of concept, to have something for the programmers to run on. Working Star hardware was years away when they started the program. The OS needed development. And the designers needed machines to debug the commands on. The instruction set was pure IPL. Some of the instructions were very complex. The Star-1B was frequently recoded as the instruction set was refined. It wasn't pretty and it wasn't fast. But it was very easy to reconfigure, the critical parameter at that time. 7. I was assigned to the Star-65 program being developed in Mississauga. It had to run at least half the Star-100 speed using the same technology where possible. We had a couple of 1-Bs for the software folks. Used the same memories and Star Stations. But the processor was a different concept: the Star-100 was a massive brute force parallel machine. the Star-65 was a hybrid using some of the streaming units, but with a microcoded main processor Damn, those were exciting times! So many new ideas and concepts being tried. Today, 30 years later, I see an occasional reminder of those Halcyon machines. For example, the streaming function in ATA-7. Or pipelines in communication processors. 8. FASTRAND II and III lived on for decodes in the Sabre airline scheduling systems from Univac. I know some were still in operation until the mid-1990s. Somebody on the list probably worked on the 490 Series. Anyone? 9. All of the early computers I worked on were drum memory based. In the Army, it was the Pershing Fire Control Computer. And the Redstone jukebox, a fixed head sealed disk, actually. But CDC trained me on the Bendix G-15, LGP-30 and RPC-4000. I can't say I have fond memories of all of them. But I did prefer drums over disks until the first Winchesters became reliable. Billy

18 years, 6 months

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test-drb June 2006