--- Liam Proven <lproven at gmail.com> wrote: Ah, then you need to go find a 6 conductor telephone cable, and file off that clip. It'll fit and work in an MMJ socket, it just won't stay in too well. Hold it in place with some tape... -Ian

--- Liam Proven <lproven at gmail.com> wrote: Ah, that's right - you're in the UK so the telephone cables won't be the same. Actually, you _might_ be able to take an Ethernet cable, file off the clip and file both sides to make it fit. If you can keep the pins centered properly after filing, it should work. -Ian

Ah, you've clearly not come across one of 'ARDs laws of vintage computing', namely that the machines are cheap, but you'll go broke buying disks, cables, plugs, repair components, and so on. The way to thin of it is not 'I had to spend 20 times as much for the cable as for the CPU' but 'I've got a nice little machine for \pounds 21.00'. :-) Next you'll be telling me you've never used a soldering iron, 'scope, logic analyser or machine code monitor either... -tony

On 04/10/2007, Liam Proven <lproven at gmail.com> wrote: Never too late to start. I hadn't touched an iron in 20 years but managed to scratch build an eeprom programmer and put together an SBC without too much investment. I look at it as mental exercise to stave off the inevitable decay of my cognitive functions as I get older. chip. I've built more machines than I can remember, fixed innumerable Shhh! You'll upset Tony :) -- Pete Edwards "Prediction is very difficult, especially if it's about the future" - Niels Bohr

Well, speaking personally.... I'm not hardware-antipathic; I know which end of a soldering iron to hold [the cool one :)], and I've hacked together assorted electronics on occasion (a few of which I've even mentioned here). However, most of my on-topic hardware, I have no particular interest in repairing below the board-swap level. So, while I can't speak for anyone else in this regard, I can perhaps address your puzzlement as it applies to me. Most of the hardware in question is SBus-era Suns. I don't run it under emulation because an emulator, plus the hardware to run it on, would cost me a lot more than the Suns cost me (which latter figure is usually $0 + shipping, and often the shipping is $0 because they're local). Then, consider some additional points: - Speed - emulators are usually slower than the real thing. An emulated setup capable of matching the real thing's speed will be substantially more expensive. - Hardware compat - I have some oddball SBus cards. I daresay PCI-to-SBus, ISA-to-SBus, etc, bridges exist, but they will be expensive, probably difficult to find, and may not even play nice with the emulator. - Reliability - as I think I've mentioned before, peecee-class machines account for a rather disproportionate fraction of the hardware failures I've experienced. "Modern" machines as reliable as the old Suns are doubtless available, but, again, that will mean a substantial additional cost. So, really, it's a total no-brainer for me whether to run the real thing or an emulation, quite aside from whether I'm prepared to do low-level repair work. Now, some of my stuff isn't SBus-era Suns. Much of *that* stuff I *do* want to be able to repair down to the chip level - for example, I have some hp300 hardware with, I suspect, a blown HP-IB driver (last time I tried to use it I was seeing what looked like a stuck-at fault). When I get the round tuits together, I'm going to see if I can confirm/deny my suspicion, and (if confirmed) pull a compatible driver chip from something else and do a swap. Perhaps someday I'll be applying the same philosophy to (say) the SPARCstation 20, and, if that happens, I'll probably then be glad I'm not chucking "dead" hardware.... /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

Yes, quite likely. For such machines this argument does not apply; that's why I specifically mentioned that most of the on-topic hardware I have and run (and was addressing your puzzlement with respect to) was SBus-era Suns. Perhaps even them, though probably not with a freeware emulator. (I'd expect it to have to do some kind of JIT compilation to native machine code to run at anything approaching full speed, and that's a but much to ask of a freeware emulator.) No, not yet. When I saw the stuck-at fault, I shelved that project, and haven't picked it up again even to the extent necessary to go looking for schematics. (Especially since it was working when I started, which means I quite likely blew it myself - perhaps I shorted a pin to a power rail by mistake or something.) When I do get back to that project, if I have further trouble, I'm sure I'll mention it here. :-) /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

Well, of course. I _did_ specifically mention that I was talking about SBus-era Suns. True. Emulation does have its place. But talking about that wouldn't've addressed ARD's puzzlement. But only in an emulated world. As a simple example, I have an SBus card that does HP-IB (or GP-IB, or perhaps both - it's been long enough I'm not clear on how similar they are any longer). An emulator might be able to emulate the card from the host-software perspective, but it's not going to be able to actually talk to other HP-IB (resp. GP-IB) peripherals over the emulated card - unless it's backed by a real interface, of course. I'm certainly not going to argue that emulation, including hardware emulation, is valueless. But that isn't what Tony was asking about. Perhaps - but only at substantial additional cost (whether money or called-in favours or effort put into digging for sources or whatever). Reliability isn't free. Of course, there is a place for reliable peecees. I'm not going to argue against them; in fact, I wish they were more popular. But they are not relevant to my explaining to Tony why I behaved in ways he found so puzzling. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

On 10/4/07, der Mouse <mouse at rodents.montreal.qc.ca> wrote: It doesn't puzzle me so much... I personally started off with a self-assembled Elf and a factory-assembled PET to which I added a number of hardware hacks (including a "Simon" addon from a late 1970s issue of Byte), so I've always approached computing, let along "classic" computing, as a tandem hardware-software experience. Many others I see and work with, though, are 100% software. I see a lot of self-induced problems from not understanding the underlying hardware, but the fact that it happens hasn't changed over my 30-year time in the field (I started young). Even back in the day, there were lots of folks who bought PETs and Apples and more, that didn't know a single thing about hardware troubleshooting and repair - 30 years ago, when it broke, they took it to their dealer, or if it was too expensive to fix, they junked it (or gave it to me ;-) I don't find it surprising that people are around today with interest in the platform, but no interest or aptitude for repairing it when it breaks. Look at how many folks work on their own cars now, compared with 1977 - same issue, different hardware platform. Certainly for now, and for the past few years, Sun S-bus-era hardware is plentiful and cost more to ship than to buy (thus the importance of local acquisition). 10 years from now, though, it might not be as easy to find on the ground - like mid-1970s micros are already. Suns, being a rather hardware-closed, high-speed (for their time), highly-integrated platform, were never routinely hacked-on or repaired by the folks running them (NVRAM replacements aside). OTOH, lots of Apples, S-100 boxes, PETs, TRS-80s, etc., were. I do component-level repair on lots of things, and I do have a lot of S-bus Suns, I really haven't done much in the way of Sun repair. One of the more important considerations is where I'd get spare parts. I _could_ component-level-troubleshoot a SPARC 2 or a SPARC 5, but so many of the components are not generic TTL parts, I wouldn't approach the fault with the expectation that I'd be able to locate a replacement part except on another similar board. I don't mind replacing SMT parts, but in the case of most of the SMT ICs on a SPARC board, I don't know where I'd locate new parts. Removing DIP parts is difficult from boards as complex as these; not impossible, but certainly lots more difficult than from a 2-sided 1970s micro. When I first started emulating classic platforms, I'd agree with you - about 10 years ago, since I couldn't manage a large enough PDP-11 disk, I built an emulated PDP-11 w/RP03 under SIMH on a SPARC 1... talk about *slooooow*. It worked, but was a small fraction of the speed of the real thing. A little later, when I had a SPARC 5 on my desktop at work, the PDP-11 was still slow, but acceptable. The 6502, via VICE, was really nice; especially being able to load files from a local directory on the workstation - I was able to *scream* through software development by editing on a 1152x900 screen, cross-compiling under Solaris, then running the binary on the emulated target. These days, with even semi-modern hardware, x86 emulation of a 1995-era machine (386-DX25 through 486 DX2/66) at original machine speeds is trivial. Emulating a VAX at original, or even faster, speeds isn't difficult. If your target is 10 years older than your emulation platform, I don't see why it has to be slow. That's an important point for a number of platforms - I used to make Unibus, Qbus, and VAXBI 68000-based smart serial boards. I still need a real VAX or PDP-11 to fiddle with my old boards. I know that there were some bus interfaces for older PCs, but I've never handled one personally. Certainly, I wouldn't expect those to work with modern PCs. Consumer-grade PCs are notorious, naturally. Server-class x86 hardware can be as reliable as Suns, etc., but not as cheap as Packard Bells, and the like, and certainly not as abundant. If you intend to do production-quality emulation, you _should_ be using production quality hosts for it. If it's just for fun, I don't see it as such an issue. In the case of Sbus Suns, I agree with you that it's reasonable to run the real hardware without being able to do more than depot-level service. I can agree with that as well - for something more obscure, like non-consumer HP products - it's much more reasonable to expect to have to delve into component-level repairs to keep them running. I think it comes down to relative abundance coupled with intrinsic complexity. If I ever had a VAX 9000, I'd want to run it, even though I don't think I have much hope of being able to find spare components, but at least I would expect to be able to track down engineering prints, unlike with SPARCstations. -ethan

"Ethan Dicks" <ethan.dicks at gmail.com> wrote: Maybe not the later S-bus Suns themselves, but I worked in many many labs where either VME-bus Suns or S-bus-to-VME-bus adapters were used and all sorts of interesting things hooked on to them. Peripheral-wise, the biggest things I ever heard most of those boxes being hooked to was a SMD disk. Kinda puny compared to what was hung off the Suns :-). And of course that's puny compared to Will's DASD chains! Tim.

Tony Duell said: [...] Maybe nostalgia. Maybe they had such a machine earlier in their life and now want to *have* it again. That's not your more engineering-like approach; fascination about tractable technology - nowadays, you are almost out of the game with understanding and/or repairing modern gadgets. There is also rather the attitude of the art collector who wants a VanGogh painting not because he likes the artwork of the painter but is aware that it is worth hundred thousands or more. Why would one want an original KIM-1 with 1,25K memory? And then, why would one want a replica of a KIM-1? That is not better than a MESS emulation; it lacks the originality for the art collector type. I for my part are of the kind of being interested in the software; the operating systems, not actually the original hardware, so I am satisfied with emulators in this area. Systems like PDP-11 or VAX-11/780 which I had worked with were black boxes for me that time, but today as an electrical engineer I probably could read the schematics, and with enough time, money, and the right parts, I could even bring defective ones back to life. But then, what would it demonstrate? Like painting a certain arrangement of sun flowers on a canvas? Not my original work - it is VanGogh's one. More interesting is crafting an own computer; that's one of a kind, and others might laugh pointing at the Intel Quad Core they just bought for the same money and less time -, and its 1MHz clock whatever is ridiculous, but it is *mine*. -- Holger

On 06/10/2007, Tony Duell <ard at p850ug1.demon.co.uk> wrote: I don't understand your puzzlement. I don't know how to change the oil on most of my bikes, let alone anything more advance, but nonetheless, I'd love the chance to ride a classic Norton or something. I am no car buff at all - I find them rather dull, mostly - but I appreciate an E-type Jag as a beautiful machine, without any idea of what's under the bonnet or any wish to know. Appreciation is /entirely/ separate from /understanding./ Most people who admire a fine oil painting couldn't paint it. Most people who listen to music can't play an instrument. There's no need to be able to /do/ something to /enjoy/ it. Wow! I honestly did not know such tech went back more than 10-15y. Amazing. -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

Tony Duell wrote: A two-stroke? I have a four stroke diesel engine where the engine oil is soaked into a foam pad. You clean the pad, re-oil it and reinstall. Peace... Sridhar

Ah, ut you said '_most_ of my bikes' (emphassis mine). The point being that if you can do it on one engine (OK, 2 strokes are a notable exception), you can do it on any. So obviously all the graphics systems for 1970s minis (and indeed _calculators__) esist only in my imagination. That'll save me a lot of space :-) Seriosuly, there were some rather nice graphical display systems for PDP11s,VAXen and other minis. Made both by DEC and 3rd parties. I don;t know if you call a PERQ a minicomputer (to me it is, the CPU is a large boarf of simple logic chips, not a microprocessor), but that had a multitasking GUI. Err , couple of messages ago you described me a 'bl**dy daft'. I hardly think that's appropritate.. -tony

Liam Proven wrote: A friend of mine was nearly killed due to this. He tested some wiring for I know a friend who installed a light fixture live. They had power coming in from the neighbors rather than the fusebox.

On 05/10/2007, Bryan Pope <bpope at wordstock.com> wrote: Er, hardly, when a modern chip has several tens of millions of gates on it! I make my meagre crust working on machines of, on average, 2-3GHz of processing power, 1-2 gig of RAM and about a quarter to a half a terabyte of RAM. I fear when one of those goes wrong, probing for a duff transistor will do me little good! I know a few dozen characters of Chinese. I also know that I could buy a Chinese dictionary, but it wouldn't tell me anything! :?) Ahhh. I'm going the other way. The recent new skills that are relevant to me are principles of firewalling and TCP/IP security, routing, DNS setup and so on. I'm also trying to learn about setting up and running Linux servers built from scratch and a bit of coding in Python. For me, the relevance of basic electronics is declining, not increasing, and I am already half way through my life and accelerating! -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

On 06/10/2007, Bryan Pope <bpope at wordstock.com> wrote: But I don't and wouldn't even /attempt/ to fix anything that old. I have a couple of vintage machines, and I'd like to keep them running, but personally, that's more or less enough for me. I read with great fascination the discussions in this group, but for me, getting my first computer in 1982 or '83, I'm not really interested in owning anything before the early-1980s 8-bit home micros. And since there were many dozens of makes and I have absolutely no use for any of them, I confine myself to the few I still have. In the later '80s, there were a much smaller number of much more powerful 16- (or 32-) bit machines. I've got one of each of the big ones: a QL, an Amiga, an ST and several Acorns - an Archimedes and an A5000 and a RISC-PC. Apart from that, it's all Macs and PCs. That suits me fine. They were all free or /extremely/ cheap. If one dies, I'll try to find someone who wants it & I'll get another one. Things like logic analysers would be of little to no use to me on the machines I work with, which contain no discrete logic at all, just a few SMT or BGA VLSI ICs. They are, for the most part, impossible for human hands to repair, and if they were, it wouldn't be economical. So, I don't. I'd vaguely like to know how to run a metal smelter, how to forge and cast metal, how to do carpentry and whatnot, but they're archaic skills of no actual /use/ to me. I'm afraid tracing a duff RAM chip or replacing a serial line driver is in the same bucket in 2007. How? Given I have no analysers and wouldn't know how to use one if I did? The Amiga cost me a copy of NT4 and a Compaq server Ethernet card. Its accelerator and Squirrel SCSI cost me ?25 together. Hard disk, RAM, cables and software were all free. If any of it dies, I'll scrounge other bits. As an operating system aficionado, I want to know a bit about AmigaOS works, as it's widely held as a classic design. I've no desire and no need to know how to fix a duff Amiga, though. No. Why would I want to? I'm not a programmer. I can program but I'm /rotten/ at it. I'd have to agree, yes. But learning to service a Model T - or, given my personal predilections as a biker, a Rudge or Douglas or AJS - would not be much help in running my ZZR1100. The owner's manual says, pretty much, check oil, chain tension, brakes and lights; otherwise, take it to the dealer. That's what I do. If I repair my PC badly, I might lose some data. If I repair my bike badly, I might die. I already have a metal arm, a metal leg and badly damaged inner ears from a severe bike crash. I don't want another. I leave it to the pros. -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

As I have said many, many times (and I wasn't joking), one reason I don't have a modern PC is that I can't afford the 'scope and logic analyser I'd need to be able to repair them. One reason I stick ot vintage machines is that I can understand them, I can do hardweare tests on them with equipoment I have, I can repair them. So? I doubt very much if I'll ever need metal-turning skills in any job I get, this hasn't stopped me from learning to use a lathe. The day I stop learning is the day I am put in a pine box. Seriously! -tony

On 06/10/2007, Andrew Burton <aliensrcooluk at yahoo.co.uk> wrote: Gosh. Well, I think that for me, the extent of my ambitions are to get my A1200 with a 68030 card in it up to AmigaOS 3.9, and then maybe to put that on the Internet, just for fun. It also has a single 72-pin DIMM slot that can only physically take a single-sided DIMM; it needs FP-DRAM, too. I have only managed to find an 8MB DIMM for it; I'd really like to find a 16MB or even a 32MB one that would fit some time. I'm also tempted to try to get a Mac emulator running on it and then offload some of my old 68K Macs. I really want to get shot of most of my kit mountain and reduce it down to just the interesting machines I actually originally /wanted/! I think we all know /that/ feeling all too well. :?( -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

OK, a higher-level description would be 'something that records a number of digitla signals and displays their relative timing'. The sorts of things you might use one for would be to trace machine code (or microcode!) instructions/addresses on a processor bus (but cache memory and even a pre-fetch buffer makes that a little hard!), checking things like handshake sequencies on an interface, recording bit-seiral signals so you can decode them later, checking state machine sequences, and so on. What it is _not_ is a majic box that finds all digital electronic faults. It's a tool, which if used intellegently will help, though. You mean oyu've not been on the receiving end of my flames about this :-). Suffice it to say I've just written a presentation where I describe that as a 'ridiculous method'. I tried it twice when I was young-and-foolish and both times it not only didn't find the fualt, it actually left me more confused. I ended up tracing the fault using test gear in the traditional way, and it took me a lot less time. The main prolems are : 1) You have to know the module you're swapping in works. This is not always certain, particulalry on classic machines. Whre would you find known-good boards for an obcure 30-year-old system? 2) E very careful if the old and new boards are not the same revision. This caught me once, I swapped in what I thought was the same board (same part number, etc), only to find (after _much_ testing) it was a later version that needed a backplane modification to work. 3) A fault elsewhere in the machine could have damaged the origianl board, and might damage the replacemetn too. An obvious example of this is a defective power supply that's damaging chips on the logic boards 4) Even if you replace a board and the machine works, you may not have found the fault. One example of this (which happened to me) can be simiplified into a system of 2 modules linked by some interface. Let's call them 'A' and 'B'. You replace 'A' and the machine works. Unfortunately, the old 'A' was working fine _and was withing tolerance for things like interface timing (but towards the edge of that tolerance_, module 'B' was failing and couldn't handle the timing of the old 'A'. The new 'A' was on the other side of that tolerance, so it worked with the fialing 'B', but in time 'B' got worse and worse and the machine failed again. Things were even more different before that IMHO. In many of my machines (and those of others on the list), theres isn't a processor chip. The processor is several boards of fairly simple chips -- simple gates, flip-flops maybe some small RAMs or PROMs. I actually wonder how you can be 'competent with hardware' and 'know bugger-all about electronics' To me those are contradictory statements. We also ssem to have different attidudes about learning new things. I tend to spend the time to learn whatever I need to fix the problem. I don't claim to be a programmer, I;d never write an OS or a compiler or an emulator, or.. from scratch. But when I had a problem which was clearly due to a device driver not correctly hadnling the somewhat odd hardwre in my PC, I learnt enough C to understand how said driver worked, and then editied the sources to get it to work. Actually, there are some ISA boards I am still looking for. Top of the list is an origianl IB< PGC. I don't suppose your Apple bits include Laserwriter spares, do they? I am looking for partially-dead boards to raid for custom chips (PALs, microcontrollers, etc) -tony

Liam Proven wrote: I think we've done this to death before. You are talking about a commercial situation where time is money, Tony is talking about the vintage gear at home, where money is usually more scarce. No business I've worked in would consider component-level repair: it is simply not economical. But at home things are different, at least for the vintage stuff. Even if you do have a spare PDP-8 to swap in, at least you've said you'll pass the old one on to us :-) Antonio No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.488 / Virus Database: 269.14.2/1052 - Release Date: 05/10/2007 18:53

---snip--- Hi It isn't obsolete, just not main stream. Almost every manufacture has a team called "Product Engineers". These guys need to locate failures to the source and determine root cause. At board level they do the same type of stuff many of us do in this group. At the chip level, they even disect individual transistor on dies to see what makes them tick wrong. No, it isn't obsolete, just done at different levels. Dwight _________________________________________________________________ Help yourself to FREE treats served up daily at the Messenger Caf?. Stop by today. http://www.cafemessenger.com/info/info_sweetstuff2.html?ocid=TXT_TAGLM_OctW…

The last is a complete non-sequitur. OK, for most of us classic computing is a hobby, and a hobby is something you do becuase you enjoy it, but that doesn't mean you don't have a learn particular skills for that hobby that are useless elsewhere (for example in your job). -tony

On Saturday 06 October 2007 17:30, Tony Duell wrote: I've wondered about that for a while now. I've used various memory diagnostics on different machines over the years, and basically they all seem to have in common that they write different patterns to memory and then read it back for comparison. While this is okay as far as it goes, how DO you deal with the situation you mention there? Another one I ran into some years back (my first purchased 386 board actually) was what appeared to be a problem with cache. I *still* have no idea whether the lockups I was seeing that went away when I disabled external cache were the fault of the cache ram or something on the MB, and I've never run across anything that appeared to be capable of testing that function. Ah. I was wondering about that too. If you'd said "PGA" I would've had a clue right off. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On Sunday 07 October 2007 13:38, Tony Duell wrote: I'm wondering what the heck it is that's breaking words, inserting equal signs, and equal-sign-followed-by-20 in various places in the quoted material here... I don't see this anywhere else but in stuff of mine that you're quoting. Odd. Fixing it gets a little old... Nor do I. But I was thinking about approaches other than just software. And maybe get a little specific about where. This sounds more like design flaws than anything else, while my normal tendency (perhaps erroneously?) is to look for some sort of a component failure. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin

On 06/10/2007, Tony Duell <ard at p850ug1.demon.co.uk> wrote: As have others, you misunderstand me. Clearly I should have spelled this out more. The fact that PC kit is so cheap that it's not worth repairing is not why I don't repair classic machines. It's the reason I /don't know how/ to repair classic machines. No... Classicmp is a mailing list. It's where people /talk/ about classic kit. The nursing happens elsewhere in real life. Salient difference! Well, although I realise that's just an example, I can respond using details of a recent real job. An AtlhonXP PC works fine with 2 DIMMs. With all 3 slot filled, it crashes, freezes or hangs. I suspect, from prior experience, a memory error. So step #1, I get a Linux boot CD with memtest86 on it, so I can exercise the RAM. With all 3 DIMMs fitted, memtest gives errors. With 2 fitted, it's OK. Try the 3rd on its own: fine. Try the other 2 on their own: fine. Try all 3 slots individually: fine. Summary: any permutation of 2 of the 3 is fine. All the DIMMs themselves check out fine, including on other machines. But on this machine, filling all 3 slots makes it unreliable. Given that I don't have a good motherboard to swap in, the resolution, then, is to downgrade it to 2 DIMMs & warn the owner not to try 3. That seems like a reasonable diagnostic process to me, and apart from fitting or removing the DIMMs, the only tests were done in software. Ah. Exotica. Most of my stuff is very vanilla, I'm afraid. -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

On 08/10/2007, Tony Duell <ard at p850ug1.demon.co.uk> wrote: I don't want to and I don't need to. Those are 2 pretty damned good reasons. AFAIK, yes, it should, but it doesn't. This sort of thing appears to be a consistent fault with old ~1.5GHz Athlon XP motherboards. It might do, yes, but I don't have any suitable spares and it's for someone who can't afford to replace it. And again, you're working on the assumption that I am you, or that I work like you, or that everyone should work like you. No, I didn't, and no, I'm not about to, because I don't do hardware repairs and if the hardware is faulty it goes in the bin and gets replaced wherever possible. No, Tony, I don't. While I have huge respect for your apparent abilities at troubleshooting, diagnosing and fixing classic kit, comments like "I won't run a modern PC because I can't afford the test equipment to analyse it if it goes wrong" say to me that you are so obsessed that you will shoot yourself in the foot and drastically inconvenience yourself rather than change your behaviour. If a PC goes wrong, one does not analyse it, one junks it and replaces it, because PCs are interchangeable commodity kit. To spend thousands on repairing something worth at best hundreds and probably in fact worth perhaps the cost of a pint or a train ticket is not sensible pragmatism, it's not commendable attention to detail, it's bl**dy daft. And to say "I won't run it if I can't repair it" is dafter still! -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

On Tuesday 09 October 2007 21:53:01 Tony Duell wrote: <much snippage> Heh, I remember troubleshooting a PC that would work with a CD ROM disconnected, but not with it connected - even if you left the IDE cable off (actually it's long enough ago that it might have been a Mitsumi interface) Guess what it was? The 'scope told me, the +12 rail was all over the place. Once the second CD ROM was connected up, it swung wildly from 9v to 15v. Why? Who knows? Who cares? Let's maybe try a bigger PSU than the dinky 130W one the case came with. Oh wow, look at that, it even runs at less than fingerprint-removing temperature... You've said yourself that you don't have (easy) access to resources like bitsavers.org, because some of the formats used require fairly modern PCs. I'd find that pretty inconvenient. I must admit, I don't just replace bits without at least trying to guess why they might have failed. Obviously if the cause of the failure is obvious, it's not worth spending time on (most recent example being (sorry folks) one of my cars, where it was "Let's see, why might these ball joints have 6mm of play? Maybe because of 19 years of British roads?"). Not keen on learning new stuff, then? Look on the pavement the night before the bins are collected. I have a couple of nice P3 1GHz desktops which I picked up like this. They may well have been riddled with spyware and viruses, I don't know. The first thing I did was flatten the drives and install Ubuntu. One of them is now at a friend's Mum's house being a word processor and internet thing, the other is in a different friend's recording studio being a sampler. I try to only use things I can repair or rebuild, but I appreciate that there are some things that should just be considered a complete replaceable part. I've repaired computer boards (the memory board for my PDP11, for one) and I've repaired "sealed" ECUs in cars (the suspension ECU in Citro?n XMs, many times). I *replaced* a ball joint, because it was 30 quid and I've got no chance of making one, especially for that kind of money. I *replaced* a serial controller card, 'cos it was a fiver and again I doubt I could build one for that. Gordon

On 09/10/2007, Tony Duell <ard at p850ug1.demon.co.uk> wrote: OK, I was getting a bit too wound up there. I've backed off for a couple of days, much aided by my phone getting cut off - thanks for "leaving the retail market", C&W. Look, it's your choice, you live the way you want. The PC with the problem with 3 DIMMs is for a skint mate & I'm skint too. She can't afford to replace it and I am fixing it for her for free for a favour. If it was a business, it'd be a bit different. Want a free PC? No problem. You could try Freecycle: http://groups.yahoo.com/group/FreecycleLondon/ Or check the skips in your local business park or trading estate. I've pulled some lovely machines out of there, and 21" monitors and so. Weird graphics card not working? Well, choose the card to suit the OS. Me, I run Linux, and these days, most things seem to just work. I'm happy to run nVidia's binary drivers on the free PC I got out of a mate at the new year. Athlon XP 2400+, 1GB RAM, 100GB hard disk, DVD+CDRW, 256MB AGP 3D card. Free for putting Windows on his new iMac for him. xBSD might be a bit more hassle but I believe they share a lot of X.11 these days. Frankly, if you want to run TSX-32, Haiku, AROS, FreeGEM, Syllable, SkyOS or something like that, use a VM. It'll be easier. I've run all of these except TSX under VMware or VirtualPC. VMware Server is a free download now; won't cost you a penny. Seriously. You don't need to spend a penny, just keep your eyes open. Fix a few CD players or something for someone and they'll give you their old PC, no hassle, I'm sure. Same goes for the OS and parts. I run a free and Free open source OS with about 99% open source apps. I use binaries for graphics card, Flash, Java and that's about it. But, yes, you're probably going to have to deal with not being able to repair the components if they die. PCs are like modern cars, or worse: designed for planned obsolescence. There are some things you just can't change in this world. If you try to be a tree, rigid and unyielding, you will get broken by the storm, blown down and smashed. Be a reed, bend in the wind. It's the only sane way to be sometimes. -- Liam Proven ? Profile: http://www.linkedin.com/in/liamproven Email: lproven at cix.co.uk ? GMail/GoogleTalk/Orkut: lproven at gmail.com Tel: +44 20-8685-0498 ? Cell: +44 7939-087884 ? Fax: + 44 870-9151419 AOL/AIM/iChat: liamproven at aol.com ? MSN/Messenger: lproven at hotmail.com Yahoo: liamproven at yahoo.co.uk ? Skype: liamproven ? ICQ: 73187508

In article <m1IdUta-000J3OC at p850ug1>, ard at p850ug1.demon.co.uk (Tony Duell) writes: To summarize: I don't give a shit. -- "The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download <http://www.xmission.com/~legalize/book/download/index.html> Legalize Adulthood! <http://blogs.xmission.com/legalize/>

On Thu, 4 Oct 2007, Tony Duell wrote: I usually check for voltage 3-4 different ways before I work on mains wiring. My first test is usually with a non-contact voltage tester. Then I test with my good old Square D Wiggy tester. If I'm really concerned, then I'll check it with my Fluke DMM. Even after all those show something dead, I still check it with the back of my hand or finger.

Hehe, that doesn't always work... Several years ago I did work for a school system installing network wiring and nice metal wall mounted tracks for it to run in (Wiremold). Some areas included the installation of power as well. Well, the guys and I were installing the power section of one of the labs, so we went down and shut off the breaker. Now, this breaker panel is in a utility room, and it's a household style breaker. No "lock-out" system available. So, we used what we normally used. Black electrical tape covering the shut off breakers, the panel taped shut, and a sign taped to the panel warning that breakers #X and #Y were shut off to install outlets, and were not to be turned on. Go back to the room, and test the voltage with the meter. Dead as a doornail. So, work progresses, wires threaded through metal tracking, installing outlets, when, as we were pulling some wire through a hole, the bare ends dragged against the metal, creating a heck of a flashbang. Scared the hell out of us. We went back to the panel, only to find that the sign and the tape were gone, and the breakers switched back on. (And of course, one of the previously shut-off breakers was now tripped from being shorted out.) Now, this work was being done in the summer time - no students. There were some janitors and other people in the building working on things, but that's about it. We never did figure out who turned the breaker back on, or why in the hell they did it. And the sad thing was, this panel was actually labelled as to what the breakers did. All anyone needed to do was pop by the room number marked on the panel to see if someone was still working on the wiring. Since we couldn't very well post guards on the panels, tape and signs were the best we could really do, save for taking the panel apart and removing the breaker. So we would always be sure to have the wiring shorted out completely at our end, and leave it that way until all work was completed. Our hope was that if some fool did turn the breaker back on, it would immediately trip. -Ian

For what its worth, those neon bulb probes are often referred to generically as Wiggies as well. What kind of monster generator did this homeowner have?! The normal little portables will instantly disconnect (breaker or otherwise) if you try to connect it to a blacked out grid, with all those people in dark houses with the lights and fridges still connected. That's one helluva load. -- Will

On 8 Oct 2007 at 16:16, William Donzelli wrote: Probably no more than a 10KVA unit, although one of my neighbors has a trailer-mounted 250KVA unit (has a 6-cylinder Detroit Diesel on it) that he picked up cheap at a logging equipment auction. But he's not stupid, either. Out here in REA-land, homes are far apart and each home is serviced by a 6600V drop connected to one or more pad-mounted transformers (usually in the front yard). (I've got 6600V direct-bury cable running parallel to my driveway, about 4 ft. down). Each drop from the buried main distribution line to the transformer has its own disconnect, in addition to a master disconnect for each branch distrubution line. It's not unusual after a winter storm to see that you and two neighbors are dark, while everyone else has power. I could see a situation where a rogue generator would produce a pretty good "tickle" on the other side of the distribution transformer. Cheers, Chuck

William Donzelli wrote: I've used a motor-generator set in the past. 8-) Peace... Sridhar

On 8 Oct 2007 at 23:22, Tony Duell wrote: Other than cost and fragility of the old analogue meters, you're probably better off using something with a low number of points of failure (a neon lamp is pretty simple). You're not interested in *measuring* the voltage, just testing for its presence or absence. That wasn't what I meant. I mean that there are people out there who will sneak around while you're working on a circuit and flip the breaker on without notifying you. It's happened to me. Fewer parts to fail and no fuses. A genuine Wiggy not only has a solenoid-type voltage tester; it also has a neon lamp indicator. Two indications of current present. ...as well as hot-chassis television sets. And the US hot-chassis radio goes back to at least the 1940s (12SA7, 12SK7, 12SQ7, 50L6, 35Z5); some of the 50's models used 7xx or 14xx loctal based tubes. Later, the lineup was usually 12BE6, 12BA6, 12AV6, 50C5, 35W4 in miniature envelopes. Hot-chassis phonographs weren't that uncommon either (70L7+12SJ7) or 117L7/M7). But all of the "All American Five" sets here used a 150 ma heater string. Many of the older ones did not have polarized mains plugs, so either side of the line could be connected to the chassis. If there was a lot of AC hum in the audio, you were advised to reverse the mains plug. Hence my comment about "DIY fixers". I've always wondered why there's no sure way to secure a residential panel breaker. Panels don't have locks and breakers look like switches with no way to tie them down securely in the "OFF" position. It would seem that a hole through the breaker toggle and an eyelet on the dress panel would allow the use of a cable tie to secure the thing. In that respect, fuses are better--you can simply remove them and take them along with you. Cheers, Chuck

A wiggie vibrates when you have a hot circuit, you dont have to look at it to know its hot i love my wiggie. On 10/8/07, William Donzelli <wdonzelli at gmail.com> wrote:

---snip---> > Hence my comment about "DIY fixers". I've always wondered why > there's no sure way to secure a residential panel breaker. Panels > don't have locks and breakers look like switches with no way to tie > them down securely in the "OFF" position. It would seem that a hole > through the breaker toggle and an eyelet on the dress panel would > allow the use of a cable tie to secure the thing.> > In that respect, fuses are better--you can simply remove them and > take them along with you. Hi Chuck This isn't too hard to do with breakers. All one usually needs is a screw driver to release the wire. Just take the breaker with you. I do recommend a little no-ox to put the connector at the back of the breaker. Dwight _________________________________________________________________ Climb to the top of the charts!? Play Star Shuffle:? the word scramble challenge with star power. http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_oct

A method (eg, neon-bulb indicators) that does not require continuity to the possibly-live circuit is somewhat safer, because it cannot produce a false dead indication due to bad contact between the probe and the conductor, since there is no contact with the conductor. No, this isn't a particularly likely failure mode, but the price of a false dead indication is, potentially, quite high. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse at rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B

Chuck Guzis wrote: People are idiots. (c)2007 Seriously, it doesn't matter what sort of warning or obstacle you provide, if your work gets in the way of their plans, they'll go around it. I was once working on a '40s-era bridge hoist that had its main wiring panel on the bridge. I had thrown the 480V main breaker, taped it down with red 100mph tape, and tied the outer latch of the breaker box down with a red flag*. I had my hands in the wiring panel (and my butt on the outer beam of the bridge, 25 feet off the floor), when the bridge took off moving! One of the welders had untied the red flag from the breaker box, removed the tape from the switch, turned on the breaker, and was running the hoist down to his table to move a finished beam. Apparently** it never occurred to him that there might be a reason for all that rigamarole. * The hoist wasn't the only equipment powered from that breaker panel, and the other stuff was live, so I couldn't lock the box. ** I'm not sure, as I never got a chance to ask him. I was told later that he complained to the shop foreman because I was throwing wrenches and curses at him, and when he explained the situation, the foreman advised him to make himself gone before I got down on the floor. Doc