Tech support chap solved knotty disk failure problem by staring at the floor Every IT pro has a story filed away about the time they were asked to provide tech support under odd circumstances, which is why each Friday The Register brings you one such story in a fresh installment of On Call – the reader-contributed column that celebrates odd circumstances. This week, meet a reader we'll Regomize as " …
Whoever designed it must have been as thick as two short planks
Builder late in the employment of one Basil Fawlty, Torquay and possibly still encumbered with a garden gnome, property of that employer..
Betty Stoggs - I had a mate who was in charge of Marketing for Skinners & he threw a whole load of merchandising my way Betty Stoggs mugs among them.
Which the Ex Mrs Oncoming-Scorn took exception to for some unquantifiable reason when I pointed out the resemblance to the character on the mugs to her mother.
The strangest problem I encountered was when the code of an image processing system which worked happily on a (for the day) powerful PC (486 @ 66 MHz, 8MB RAM, and a Matrox MVP-AT/NP image capture and processing board) in the microbiology lab where I worked next to an Olympus fluorescence microscope, borked when running on essentially identical hardware, and same MS-DOS version, in the department of dermatology, next to their very fancy Leica fluorescence microscope. Mysteriously, a previous version of my code worked fine on both. The bad behaviour only showed up when the mercury UV lamp used for fluorescence microscopy was switched on, and only on the Leica microscope. I suspected an RFI problem, but the mystery was why it only hit the new code. Switching back to the old release solved the problem, but the old release was for a Matrox MVP-AT board. The MVP-AT/NP version had an additional "Neighborhood Processor" (hence the additional NP) which was essentially a hardware accelerator for image processing tasks. Not using it caused a significant slow-down in processing speed. The "solution" was to replace the image capture part of the code (when the fluorescence microscope had to be switched on) with the MVP-AT version of the code, and do the offline processing of the data with the faster MVP-AT/NP version of the code.
This was far from ideal, as switching the Leica UV lamp on and off could cause the computer to crash anyway, so the protocol became: switch the computer off before switching the fluorescence lamp on, start the computer up, do your image capture, switch the computer off, switch the UV lamp off, switch the computer on and do the offline analysis.
Everything was earthed properly, but the Leica power supply was simply a beast which when switched on caused lights to dim briefly. It should never have been certified for use in general, let alone in a hospital, in my opinion. The Olympus and Zeiss power supplies for exactly the same type of mercury UV lamp caused no problems whatsoever.
This used to be a common problem with xenon arc lamps as well. First instruction in the S.O.P. "Turn on the lamp BEFORE starting the computer..."
Equipment designers have made progress in PSU arrangements over the last couple of decades, grizzled lab staff buyers roll their eyes if you have to explain why bits of your new Whizzo-XX+ have to be turned on in a strict order!
I once solved that sort of problem. Turned out that on the other side of the wall from the--then--top of the line Viewsonic (23", I think) monitor was a un- or poorly shielded power distribution panel. The correct fix of properly shielding the panel was off limits because it would have been too expensive. So I suggested replacing the video card in the PC with something that could drive the monitor at a frame rate other than 60 fps. The client put in a Voodoo 2 (then rather obsolete, an therefore inexpensive) cranked the frame rate to 85 (avoiding an obvious beat frequency) and was very pleased with the steady screen.
Picture a data center in the basement of a tall building in San Francisco's financial district. Card punch up against a wall, near the ancient Otis heavy goods lift. Every now and again, at seemingly random times, the punch generated errors for a couple characters. Nobody could figure out why, not even IBM's field circus dudes.
Until IBM was traipsing in and out one fine weekend, upgrading who knows what hardware, as only IBM could. Someone (ahem) noticed that the gibberish was being generated about ten seconds before the elevator doors opened.
Turned out that the motor for the lift was drawing so much current when it first started that it was inducing errors in the punch on the other side of the wall. Nobody put two and two together prior to this because the lift rarely went into the basement (that level was key-protected) ... until IBM was in and out that morning.
Once I figured it out, and could reproduce the problem at will, a little shielding (spec'd, provided and installed by IBM, gratis!) made it go away permanently.
(have told this before...)
Wine merchant has a leased-line modem link to HQ that occasionally would error, but by the time we turned up would be working fine. We tried swapping out bits but no joy.
Then he had a theory... the errors seemed to be occurring around the time the café next door opened... could it be mains noise?
We picked up a mains monitor from R&D and turned up early next day to set up ready.
Around 9AM we were sat back, sipping a very agreeable sherry, waiting for for chaos to break loose... nothing!... then the guy got up, walked across the room and got a ledger from the cabinet... errors galore!
Yes, the offending cable ran under the carpet from his desk in the middle of the room.
"My (17" CRT) screen image is wobbling, come fix it!"
In addition to the processing chips Zilog also made some complete systems. We had two different models of them, all lined up in the machine room with the consoles sitting on top of them. On one model the consoles were stable, on the other they had a continual shimmy. I think those may have had their disk drive at the top of the case instead of the bottom.
In the late 90's I used to have twin 21-inch Samsung CRT monitors at the office and learned the hard way not to power them on or off at the same time. The few times I did that I managed to trip the whole floor. And each of those times several angry looks followed my walk of shame from my post to the electrical board to switch it on again.
>>That reminded me of the first time I moved a computer with needing to park the disk heads first.
was there a bolt in the bottom to fix the spindle as well?
Forgetting to remove said bolt and powering up the drive might have resulted in the escape of magic smoke... I couldn't possibly say.
No... wait... you said "moved a computer" not "moved a hard disk".... as you were.
Icon - it looks like magic smoke to me!
I had a Data General Nova 4 in a full-height rackmount ... in my 3rd-floor flat. When it came time for me to move house, I removed the removable disc cartridge -- the 6045 was a 5MB fixed disc + 5 MB removable disc drive in a 4U box [and heavy] -- disconnected the box, locked the heads, and had two friends help me get it off the rails and down the stairs. Then we did the floppy drive, the backplane box, and finally, the now-nearly-empty (fans in the bottom) rack itself.
I moved to a flat in another city ... on the second floor.
True friends, those.
SparcStation4s had the opposite problem. They use some Maxtor drives that were prone to auto parking their heads and getting the head mechanism stuck so that they wouldn't unpark. Seen to recall that there was a semi-official solution from Sun which involved turning the base unit onto its side, lifting it up from desk a small distance and letting it drop and trying to boot again to see if you'd managed to dislodge the disk heads!
I recall for the disk unit itself the recommendation was to drop the drive 1 metre onto a firm surface. I think these were 5¼" (133mm) full height SCSI drives built like brick shithouses or more genteely (or is that less?) a Soviet T34 tank so dropping one was more likely to damage the surface it landed on.
I went for a large screwdriver held by the shaft and the drive in the other hand and then the end of the handle sharply impacted against the drive roughly where the spindle might be.
In most cases it would have been mostly a case of "you can't kill that which is already dead" (Cthulhu excepted, perhaps.) The resurrection* rate, albeit low, made it worth trying.
* disks not Lovecraftian deities.
"SCSI drives built like brick shithouses"
I always thought the drives in the HP 9000 kit that replaced the Zilogs (see above) were like that. They were enormously heavy ant the engineers had a sort of crane that clamped onto the top of the cabinet to move them. Maybe things were different to what they seemd because the engineers seemed very relieved when a move went successfully.
Early in my IBM days I worked on refurbishing machines called RAMACs, named after the original magnetic disk drive. (Which had the delightfully 50's name of Random Access Method of Accounting and Control).
Anyway, these things had up to 16 "drawers", each one with four SCSI drive modules. When we first powered these up we'd check to make sure the lights on all the drives were blinking. Any that were not we'd pull, hold out at arms length, and the raise it up high, swing it down, and stop suddenly. That usually worked!
We'd then put the drive back into the machine and "rebuild" it (I suspect that reformatted it).
I once wrote a TSR (Terminate and Stay Resident) program to park the heads of my computer at work after a certain amount of time, and the Boss was so impressed that he had it installed on all the computers in the department, and I was promoted to Deputy IT Manager despite having no qualifications and being only self-taught.
Had a site visit donkeys years since upon - pre PC days, in fact. The client, a research bit of a major oil company, had an ISC3651 colour desktop computer. 8080 based, with a staggering 16k of plug in ROM for the operating system on the A3 sized mainboard and a 50 way parallel expansion port on the back, which we'd plugged into our interface.
This is a similar beast: https://vintagecomputer.ca/intecolor-3600-series-computer/
The client had been complaining of random crashing and muggins was sent up to have a firkle.
Disconnected the expansion cable and extracted the mainboard. Had a close look and no obvious issues. Maybe it was one of the myriad connectors. Reassembled the machine, tested and crash. Rinse and repeat several times, increasing the scope of connector unplugging/reseating.
Crash, crash, crash.
After the umpteenth time I had just reassembled and was powering up when I realised I'd forgot the expansion cable. I reached across the top of the machine to plug it in (ok to do live). As I leant on the top of the case - crash. Lift off hand - back to life. Repeat with the same outcome.
Interesting.
Pulled mainboard again and got a magnifier. Started scrutinizing the board with a really intense scrute.
Found one data pin in one of the plugin ROM holders had never ever been soldered. The pin was just pressed against the side of the plated thru hole
30 seconds with a soldering iron and it was fixed.
And that thing had been running an engine test bed for 2 years like that.
I worked on some of the other Intecolor terminals as a YTS trainee. They were notorious cheap with the IC sockets - we often had to replace them them with better quality versions.
This is where I learnt about "faulty metalwork" - once you have changed all the circuit boards, cables etc and it still doesn't work, therefore it must be the metal framework that is faulty.....
> I learnt about "faulty metalwork" - once you have changed all the circuit boards, cables etc and it still doesn't work, therefore it must be the metal framework that is faulty.....
Ditto. Panasonic 286 desktop in a piano technician's shop. "No-reason" crashes. After all the obvious, we took it out on a clean bench, took all the cards and HDs out, turned upside-down, and beat it. Some metal chips fell out. Ran fine thereafter.
Another much later. Cheap 386SX clone. Locked-up about every 13 days. Was dept server so always in use. Finally called hard down time and took it apart. Found a small screw under the motherboard just lightly touching a trace. Again rock-solid when cleared.
I had a sort-of similar issue recently with my fab new isolated power supply design. This has a driver into an isolating transformer with a recifier on the other side, and the driver has some voodoo way of sensing the secondary voltage without an opto isolator.
Anyway, it worked perfectly on some units but not others, and if you touched any part of the secondary circuit with the oscilloscope probe /without the negative connected/, they all worked. Hmmm, thinks me, some sort of capacitance issue between primary and secondary sides.
Nothing in the datasheet. Nothing on the internets, forums, or anywhere else I could find. Many experiments revealed nothing. Until, when I looked at the demo board circuit, there it was: a 1500V 4.7nF cap across the isolation barrier.
Why not actually put it in the datasheet then? I hate it when they do that, it wasted days.
Nissan Micra K11s were notorious for failing to proceed because of a fault mass air flow (MAF) sensor. The cure was either (a) to buy a new throttle body from Nissan at the cost of a couple of hundred or (b) to remove the cover from the MAF unit, touch a hot soldering iron to three joints and replace the cover. I once got a very nice car for fifty quid because the owner despaired of getting it to run ... the repair took about ten minutes.
They were Z-80 based. Each terminal had its own CPU, and a "master" CPU to handle the I/O. The removable disk(s) were DRI 4000 series[0], the fixed disks were Diablo something-or-others. The whole thing was almost entirely British Built.
[0] Data Recording Instrument Company, a part of ICL if I remember correctly.
Back in the dark ages when a 486 was the dog's doo-doos, our analysis lab (large chemical company) bought a top of the range IBM tower case. As the bench top was too cluttered for this beast (nearly 30" tall and about 24" deep plus space for the cables) it was installed under a desk. This thing was connected to a set of analysis machines which periodically made the processor run at 100% CPU for 10-15 minutes at a time processing the analysis data.
Then it started throwing wobblies and producing various random errors. It was removed to the IT dept where it worked fine. It went back & forth between the lab and the IT bods for several weeks.
Chatting to the lab manager whish waiting for some results from said machine I realised that it was located up against the hot air duct that provided heating to the lab. The heating would turn itself on and off based on the room thermostat and in this case the computer was sucking hot air into the CPU which was getting it hot enough to start producing errors. This only happened when the machine was running at 100% CPU and the heating was operating at the same time, hence the randomness of the problem.
Moving the PC to the other side of the desk stopped the problem.
Had similar with a whole bunch of Cyrix586 based PCs in an old Victorian building. The heating system was ~4" diameter cast iron pipes that ran around the building a little above desk height and so ran along the wall directly behind the PCs. This was the time when Pentium grade CPUs ran hot and had thermal shut-offs to protect from overheating and burning out. Except the early 586/686 grade Cyrix didn't have that feature. On a similar note, a certain supplier sent out a batch of 586/686 based PCs with the plastic peel still on the bottom of the heatsinks.
We had a then very new VAX 11/780 installed in 1980. It powered the designed and engineering office, but also extended a terminal to the lab, on the factory floor. This used to run all sorts of funky electronic test equipment. The VAX kept blocking one of the async terminal cards. The engineer kept coming in, humming, harring, but replaced the card. We must have had 4 or 5 in the ifrst year.
The lab was a fair distance from the VAX. Rather than invest in long-line remote options for the async terminal from digital, the machine room manager decided to wire up a very long belden cable which was slung from the window of the computer room, over the heavy machine room, in tough another window to the lab. Fairly cheap, but definitely NOT in the Digital approved way to connect a terminal.
For reasons I didn't understand they used unearthed power leads to their oscilloscopes. All such plugs were colour red to alert people. They also had red painted un-earthed extension leads. And yes, it was into one of these that their RS-232 asynch terminal was plugged. The cable tended to float high, not being earthed. And eventually the high voltage would flash over to the other parts of the terminal concentrator board and blow its TTL circuits.
The solution was to plug the terminal into a properly earthed supply. We never did tell Digital why the problem went away!
Sadly, the computer room, lab, engineering workshop are all destroyed and are now a nice little housing estate on the banks of the Manchester Ship Canal.
Unearthed 'scopes were often used when working on live-chassis equipment like TVs. Clipping an earthed scope probe onto the chassis of such a device could have spectacularly expensive results.
The correct solution was to feed the equipment under test via an isolating transformer, but they cost money...
Older CRT tvs were like this, had a bridge rectifier directly on the mains with the negative connected to chassis 'ground' so it was always live with half mains voltage. The aerial sockets were isolated with 2 capacitors. I found this out after replacing a damaged aerial socket with a non isolated variant. I found out when 20 feet up a ladder, was aligning the aerial, and got a hefty whack from it when i touched the dipole element, was damn lucky to not leap off the ladder
Is that still done? It sounds mildly hazardous.
Either it is unavoidable in which case, ok, fine, or it can be avoided at some cost in components and in the last 40 years those components have become cheap as chips, or they are still too expensive and there are still gadgets lying about with a live chassis.
I learned the hard way about sneak circuits and grounding in high school when I worked on a mains-powered transistorized tabletop radio.
BANGFLASH!!
When I could see again, I saw a two-inch strip of PC board foil had been vapourised, and the ends lifted off the PCB. I fixed the self-induced, additional problem by X-Acto knifing off the ragged PCB trace ends, and soldering a piece of bare wire to each of the two PCB trace ends.
After-the-fact, I saw some sort of faded, printed warning on the radio's fibreboard back panel.
(Icon for "Caution: Live Chassis")
I had a battery powered scope which was ideal for such things - a lovely little bit of kit. More recently I was using a big old CRT scope and got zapped from it because the earth was disconnected, I know why because when it was connected it caused other problems.
Battery power is much better than no earth.
I had a PC turn up for a demonstration session. It had been packed in a shipping crate and flown over from the US to the UK. Let's just say it rattled when I took it out of the case. After plugging back in various cards that had fallen out of slots, the machine booted up but flagged errors on the disk. One disk check/repair later, the system booted up OK. So I shut down the computer, stood it upright, powered it on and I saw more errors. Now I don't know why, but I decided to lay the machine back on its side, re-run the check/repair, and all was OK. The system booted fine. Put it back on its base, and I'd get errors. So I ended up leaving the machine on its side for the demonstration session (2 days long). How it made it through I'll never know!
I had a set of units that came back from customers as faulty but it was very hard to reproduce. I eventually discovered that it was due to a micro crack caused by a common event on these boards that only showed up when the device was in a certain orientation. When on my desk this was not the natural orientation and it worked fine but in the machine it was at 90 degrees and the weight of the sensor opened the crack.
Caused much head scratching until I found the pattern.
Had a similar issue in my PFY days. 486 computer out on the production floor. Boot up, type something, nothing shows on monitor. Brought to IT workstation, everything worked fine.
After some experimentation, found that if the PC was laying flat (how it was positioned on the production floor) and you typed something in, nothing typed world show on the monitor. If you then tipped the PC up like a mini tower (how I placed it on my workbench) , the typed text would suddenly appear.
Joking diagnosis: bad keyboard pump, standing it up allowed bits to flow by gravity from the AT port to the VGA adapter.
Actual diagnosis: a loose ~10mm compoment lead* was sitting next to an IC. When the case was standing up, the lead rolled harmlessly against a plastic connector (ISA slot, maybe?). When the case was laying flat, the lead contacted a few pins on an IC (most likely the keyboard interface).
*this was at an electronics assembly facility in an era where we still built a lot of through hole assemblies. After soldering, leads were often hand cut with side cutters, which causes the trimmed leads to fly everywhere.
Maybe "engineering" like an S-100 box we had. Humongous electrolytics in the power supply had screw-on terminals. I'm pretty sure they were designed to be securely fastened with clips round the body with either leads or light circuit boards mounted on the terminals. Instead they were screwed directly onto the motherboard balanced on and solely supported by the terminals.
I may have posted this before but back in the mid to late '80s we supplied a system to an office plant rental company, the sort that supplied and maintained potted plants to offices all over London. A 386 box running Xenix with about six serial terminals, it was installed late autumn when they said business was quietening down and had run fine through the winter until suddenly the customer complained that it was crashing a couple of times a day most days. Suspecting something to do with the usage increasing we took a look and did the usual sort of diagnostics but couldn't find a problem, and after a couple of weeks the problem went away. Some months later the problem started again so I went in to have another look. I wanted to speak to our contact who'd just gone out to their massive greenhouse, and as I joined him I heard a grinding sound and looked up to see the windows being opened by a system of rusty gears and motors. "Yeah, it's controlled by thermostats" he said, pre-empting my question. "...and it happens in spring and autumn but stays closed all winter and open all summer?" I hauled him back to the office and sure enough we were met by the users waiting for the system to reboot. One UPS later (that they'd said they wouldn't need when we originally quoted) and they were happy horticulturalists.
Late '80s... The QA lab of a pharmaeutical company in the south of England, with various models of Trivector "Integrators" connected to Gas Chromatographs (GC) and High Performance Liquid Chromatoraphy (HPLC) machines - These would do A/D conversion of the signal off the hot-wire or UV detector and store the data on floppy discs (earlier models were 8 inch, then 5 1/4 and latterly 3 1/2). The integration software would do "peak detection" and the areas under the peaks was used to calculate the concentrations of the compounds of interest in the sample being analysed. Printers were (Seiko?) plotter/printers that took thermal rolls.
When they wanted to do "LIMS' - "Laboratory Information Management" - Trivector supplied a 80186 based device housed in a square tower unit - all the "Integrators" were connected to that using a Trivector "Data Concentrator" device - either using RS-232 or fibre for the later integrators. Connected to it was a Wyse terminal.
The analysed data from the integrators was stored on this device on a database instance of a contemporary version of "Dataflex".
A PC clone with a fibre optic ISA card was also connect to this - IIRC, the data partitions were mapped as other drives on the PC. That was a handy way of editing Dataflex source programs using the PC rather than the terminal on the device, but the original purpose was to upload data to an IBM mainframe via this PC.
The Trivector company that produced these folded some time in the early to mid '90s, and some of the service engineers formed a company to support the systems. We even sold some of the integrators to them when those were retired off, to be replaced with PC based data acquisition.
Note: Not a typo, it was an 80186 - can't recall the OS
Incidentally, Dataflex is very much active, and the company, Data Access Corporation is still headquartered in Florida.
Yes, I did some Dataflex stuff too. Our networked integration was initially Nelson data concentrators on a LAN loading into a PC. Nelson also did our first LIMS. Eventually, I wrote a new LIMS using the same R:Base database as Nelson, then I added Business Management Systems. Eventually we moved on from the Nelson to VG...
"Note: Not a typo, it was an 80186 - can't recall the OS"
Yes, seems to have been a relatively rare and short lived CPU. IIRC the BBC micro had a Co-Pro connectable via the Tube interface for running MS-DOS making it "sort of" PC compatible. I think it turned up in some schools RM machines too (Nimbus?) It was basically an 8086 with extra functions to reduce the number of external support chips and, I think, the extra/new instructions.
"relatively rare and short lived CPU"
Intel made 'em (and the sibling 80188) for over a quarter century. They were (and still are!) common in industrial controllers, and some fax and modem cards used them. The PC market pretty much ::yawned:: at them, with a few notable exceptions.
And some posts from someone who was working there at the time...
Clean floors...
Yes, to clean the floors, they used acidic cleaners (to get the gunk off the linoleum floors). The problem: this produced acidic vapors they migrated into the core memory stacks which were heated to insure consistent operation. Not noticed UNTIL said computer was moved downstairs, and a little shock was induced. So, snap goes the wire inside the core memory stack, and it died (*SIGH*). Good news: One of the lab guys picked up a compatible core stack from a surplus store (such luck), and I got it back to be operational again. Sadly this machine is lost after many moved (Oh, well).
Not quite as old, but I have a vaguely similar experience.
When I worked as a Student in a University IT shop many years ago, I got called out to look at a Macintosh (first-get PowerPC I believe) that was suffering from some drive corruption. This wasn't super uncommon back in the day. The old HFS file systems would slowly collect errors and eventually every Mac would benefit from a repair with good old Norton's Utilities.
This one was a bit odd though because the drive cleaned up fine, but the Dr. in that office called me back a few weeks later with the same problem. Not a big deal.. took the bus across campus, ran some diagnostics and the Mac was happy again.
Then it happened yet again in short order, but this time I spent a little more time looking around her small office while I was waiting for Norton's to finish its work. There, on a door to an adjoining utility room, was a sign warning of risk of electrocution if you entered.
It turned out, her office backed up against a Utility room that had a large Transformer In it. It turns out, by placing her computer on a desk against the adjoining wall, she was slowly but constantly degaussing her hard drive.
Even though the office was narrow.. probably only about 6' across.. I told her to move the computer to the other side of the room and like magic, she never had another drive corruption issue. :-)
I had a call to a domestic setup in a a property in a terrace row of townhouses
Lady had one of the early iMacs (coloured one) and kept it on the worktop in the kitchen-diner.
The problem was that every evening between 5 and 6, and sometimes around lunchtime, the Mac would literally throw a wobbler for 5 or 6 minutes - sometimes up to 10 minutes.
The screen would dance around and effectively become unreadable. The rest of the time it was perfect.
I sat around and watched and sure enough, 5 minutes if wobble happed just as described. Then it stopped and everything was fine.
As we weren't actually doing anything apart from drinking tea and watching the screen I concluded that it was some sort of external influence, and possibly from next door.
Turned out that the house next door had a mirror-image layout.
Matching the iMac's location on the kitchen worktop was a large microwave oven.
We moved the iMac to the other side of the room and she had no more trouble. (apart from finding a Mains extension cable after 6pm!)
It did come first and was £100 cheaper, it could be upgraded by soldering in another 16K of chips, but everyone went for the B.
I wanted to name my children Model A and Model B, but the wife insisted on Alexander and Benedict. We stopped at two, so we never had an argument over the next names of Master 128K and Master Compact.
When my kids were at school, I was pressed into upgrading from my beloved Spectrum to a BBC Model B, because that was what was installed at school. I purchased one second hand, but it came with an inbuilt problem, it would crash after about ten minutes use, and refuse to reboot for about half an hour afterwards.
I took it out of the case and used a coolant spray on the memory chips, which would keep it up and running continuously, so long as the chips were kept frozen. I also noticed that all of the memory chips were plugged into chip carriers, although all of the other devices were soldered directly onto the board.
I was discussing this with a work colleague, and he suggested that perhaps there was a problem with the original memory chips that had not been solved by replacing them, and that the problem might lie elsewhere. He then looked very closely at all the other chips, and noticed that the Memory Interface chip was of the wrong sort, it was supposed to be a Fast chip, but was not.
I left him to unsolder it and replace it with yet another chip socket, while I drove over to RS in Corby to buy two of the correct chip (in case we damaged one), and when plugged in this solved the problem.
Apparently, the timing of the Read/Write and Refresh cycles would get out of synch as the chip warmed up, and would resynch after cooling down.
They were advertised as being available at the same time, but several components including the fast RAM chips that the model B required (I think it was because of the high resolution graphics modes needed the RAM to be clocked at double the system clock speed, which was already fast at 2MHz) and the fully functional ULAs were in short supply, which meant that Acorn shipped model As before they could start shipping Model Bs.
The model A also was missing the second 6522 required by the printer and user port, and I'm not sure that they had the A-D converter.
If you had ordered one with a disk controller, you would have waited much longer!
I put my order for a Model B in on the day the order forms first appeared in the magazines, and ended up waiting around 6 months for my system to arrive.
In the late 1980s, the company I worked for sold a 286-based clone PC, MS-DOS, and an accounting package to the town government of a small, picturesque village ~250 miles away from our office.
Problem: random reboots reported by the (two) users.
The PC was shipped back to my office. Ran system, CPU and RAM diagnostics for a couple days. NTF. I poked around in the app. NTF. We shipped the box back. Two days later, more reboots. Road trip to customer site. Box is sitting on a desk, well-away from the wall, plenty of airflow, etc. I ask about photocopiers, laser printers, refridgerators, freezers, coffeemakers, etc. on the same power circuit as the PC. They said, 'Nope'. I physically-investigated. Nope. I had them show me their use of the app. No crash. I sat down, ran this-and-that, went into the app, puttered around, and ... REBOOT! WTF?
I was tired from the long drive, and from working all morning; customer suggested I take a break. I walk outside onto the front porch, lean against the railing, and look around. It's a beautiful, sunny morning. I look up at the building. I see the mains lead. My eyes follow the lead to a power pole and attached transformer. My eyes follow the HV leads to another power pole. My eyes follow the HV leads to a third power pole ... then back to the second pole ... and down the mains leads to a large, metal industrial building ... and to the huge, open doorway, which I cannot see into because it is dark inside. Then, I squinch my eyes shut, because inside that building, they are arc-welding!
One powerline conditioner box later, no more uncommanded reboots.
@An_Old_Dog
Once, when an "Old Dog" was retiring, I wrote on the leaving card, something along the lines of///
They say "You can't teach an Old Dog New Tricks"
However, "You can learn New Tricks from an Old Dog"
I use variations of that occasionally, less so for Old Dogs as they are a bit thin on the ground now, and I too am, an Old Dog, but to remind young whipper-snappers to listen to experience..., usually after the provobial has hit the fan, and I have to step in and put things right/show a better way to go about things
Look at the article's graphic is seems almost like looking at a Victorian book illustration.
The technician or engineer in (long) shirt sleeves, necktie and slacks with mandatory (drawing? r0toring?) pen in shirt pocket, short hair and side part. (I would guess a HP-65 calculator in its pouch also hangs off his belt. :)
The boss - suit, cufflinks and (old school) tie with dapper moustache looking rather like a sanitized Enoch Powell.
UK 1982 was more than a little bizarre but Thatcher presenting the Japanese PM with a ZX Spectrum has to be a standout.
We always had problems getting business visitors for their first trip to Belfast, but after they'd been once and discovered the hospitable pubs we couldn't keep them away. It got annoying around Christmas when we wanted meetings in London for Christmas shopping, but they insisted on having them in Belfast because it was more fun.
I had a site in the late 80s where one particular machine would get its drive (MFM in those days) scrambled. We would visit and run the low-level format on the drive, restore the software and all would be well for the next couple of weeks.
Then I was there on a different job when someone came out of their busy operations room and said "It's happened again".
So I got to see the PC in its normal environment rather than having it extracted to the quiet outer office.
On top of the processor box was an old-fashioned telephone with a loud bell. When it rang the magnetic field killed the contents of the rotating platter just beneath.
I nipped a hundred yards down the road and bought a new telephone handset complete with electronic squawk. It cost less than the fuel for a single trip to site, and we made more profit from the support contract after that!
RFI is still a problem, and 12V LED lighting is a frequent problem on boats, where it can interfere with VHF radios. Cheap LEDs use a low-cost circuit to drop the voltage from 12V to the 3V (or whatever!) voltage required by the LEDs. Many people have reported this - LEDs with decent dropper circuits are fine, but some aren't!
As Emmett surveyed the situation, he noticed that every time a file was retrieved from a filing cabinet, the drawer slammed shut and caused the floorboard on which it rested to jump into the air.
The Trivector sat at the other end of the room – on the same floorboard.
I thought it was going to be Fred Colon waiting outside the door.
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