Sysadmin crashed computer recording data from active space probe Welcome again to Who, Me? The Register’s new column* in which readers confess to times they performed sub-optimally and broke important stuff. This week, meet “Fred”, who begged us “Oh God, please don't use my real name or contact info.” Fred’s desire for anonymity stems from the fact that in the late 1970s he worked for a …
Not convinced this column is going to work.
My reading of this story is that Fred is innocent: he had no reason to know that removing a printer would hurt anything, and noone would have thanked him for bugging them about every individual box he moved!
If this is the best facepalm you can come up with so early in the column, how are you going to persuade others to contribute more cringeworthy stories? Are you going to put people under hypnosis to try and dig up traumatic memories people have buried deeply for self-preservation?
When the first computers hauled themselves out of the ocean they talked to each other through a long coax cable that went from one computer to the next in line. Each computer would have a T-junction connector plugged into the back, with the base of the T in the computer and the coax lines on each side. To prevent the signal bouncing of the ends of the cable each end was fitted with a terminator (pictures).
When a user decided the network was the cause of all their problems instead of unplugging the computer from the T junction they would unplug both sides of the coax. As well as breaking the network in half, each half would not be able to communicate because each had a missing terminator.
When computers came down from the trees they talked to each other over SCSI. SCSI worked like 10Base2, either with a ribbon cable with multiple connectors for up to 8 devices or each device had two connectors so they could be daisy chained together. Again, a terminator was required at each end (sometimes a separate dongle and sometimes enabled by setting jumpers in the device). Unplugging any device again broke the bus into two pieces that wouldn't work because of lack of proper termination.
Someone with a greyer beard than mine is required to explain IBM 360 peripherals, but I can easily believe unplugging either end of the cable would crash the mainframe and that the PFYs of the time were expected to know this.
Clearly the time has come for me to wire a motion sensor to a Raspberry Pi so it can shout "Get off my lawn!" when any of the neighbours' kids get close.
I recall some grey cables to, for example tape drive that were thick as your wrist, had to be two, and had a connector at the end as big as a phone handset.
At one employment we did some "archaeology" to remove extensive abandoned cabling left in the floor void as it was so extensive it was getting hard to route new service. This is what you get for having third parties remove kit, whats under the floor is not in the contract...
my only claim in the area of spectacular failure is limited to deleting the online backup before dropping it to tape. This was not the day we needed it (that's another story line of closest spectacular near misses)
@Flocke Kroes
I managed to get a free SCSI set-up, because a friend couldn't work out the termination properly. He was about to through the lot out in a heap and I said I'd have a look.
"Just take it, if you can get it working, you can keep it!"
Set the jumper terminator on the ISA card and it "just worked". That was an Adaptec card 3 HDDs, 40MB, 80MB and 20MB.
I also remember taking an Apple SCSI disk box for a Mac Plus home and plugging it into my Amiga.
"To prevent the signal bouncing of the ends of the cable each end was fitted with a terminator "
There were also the half-educated users on 10base2 who knew terminators were used in some way. Removing their terminal they would then add a terminator they had found from somewhere. This could also upset the network - even if it had the correct resistor value for that type of cable (50 or 75 ohm).
I remember one drunken student pulling that stunt in a lab full of PC's... Remote-booting DECStation 316sx's that had no local filestore, not even a floppy drive - and these were machines from the Time Before USB.
Damn fool took out every segment in the lab, and this was two hours before a dissertation deadline.
Fortunately for him, I managed to bundle him out of the lab before anyone else realised what was going on.
Unfortunately for him, I then decided to hand him straight over to his department head. Go directly to Jail, do not pass GO, do not collect £200. Nasty, but safer than handing him over to the baying mob back in the lab who just lost their essays.
(Yes, they HAD turned autosave off, and learned a very hard lesson. It also prompted replacement of the old kit)
Well, them being TTL and also being chain multiplexed buses done with cables... I guess it is obvious what happened.
I think they were also unprotected, so that could have fried the multiplex, but that is just a guess.
I had to admin one of those, and I did not enjoy it.. the thing was slow, and because of age, not very reliable if you needed to turn it off (and we had to, I know that is a bad idea)
"When a user decided the network was the cause of all their problems instead of unplugging the computer from the T junction they would unplug both sides of the coax."
They would then be told that they'd leaked all the ethernet out of the cable and their desk would have to be taken away for decontamination.
Ah, good old "thin wire" Ethernet. It was supposed to be an improvement over "thick wire" Ethernet where connecting a new node involved finding the thick co-axial cable that gave it its name, and boring into it with a connector that broke through the shield to get signal from the core. But we all knew that token ring, with its shoebox sized distribution points, was going to be the future......
My previous employer took over a building as a regional office and it was still wired up for Token Ring! :-O
They had to re-do the every patch box and the patch panel to get Ethernet! And on some of the desks, they only managed 10mbps... Queue wails of pain and investment in new cable being pulled through the building.
You could just about moor a boat with Token Ring cable. We had a small temporary working TR network in our lab that had cabling taped around the walls, back of desks etc. Our company telecoms engineers came in one weekend to "make a proper job" of the cabling by running it in the wall panels and connecting it to wall pattresses. We came in on Monday and admired the new pattresses etc., then we connected the server to the IBM PS2 clients on the ring and nothing worked. We fiddled about for a bit before taking a wall panel off and found that our new network was cabled with standard POTS twisted-pair wire. When we called the installer in, he explained that the IBM TR cabling was "just twisted-pair" and that the POTS wire was the same, so they had used that because the IBM stuff didn't bend around corners easily and needed large holes drilling through the walls. After taping everything back like before, the engineers came back a few weeks later and wired it properly. Less than a year later it was all ripped out and replaced by a new building-wide system using 10-5 and 10-2 Ethernet.
Once upon a time we shared data between two systems with tape reel sneaker net. Along comes Ethernet, but we had to get the OK from Dyspeptic Company Owner. First up was Nervous Team Leader.
NTL : We have a problem.
DCO: I don't want to hear about problems.
NTL: erm erm erm
Me: Ethernet will let us share files instantly and cut our turnaround time.
DCO: Can we do this?
NTL: Yes....
DCO: Then do it.
Shortly afterward co-ax cable as thick as your finger made its way through the false ceiling.
We ran a Token Ring network with over 256 devices attached on Phone cable (type 3). One day 2 of my co-workers returned from an IBM info session and stated that they had learned that TR could support all the nodes on the backup route, that is, instead of having all the MAUs connected, 2 were disconnected from each other turning the ring into a horseshoe, and they were going to test our backup route. They pulled the plug between 2 of our MAUs and immediately crashed our network, leading to our discovery that we were already running on the backup route.
Also, although I worked with IBM mainframes as a system programmer, I was not aware that you could not just yank the bus and tag cables off a peripheral without causing an issue. On the other hand, I never had any need to know this as IBM did all our hardware support, and we never removed any older hardware, just added new.
I've personally seen >$120,000 yachts moored with nothing more than shore power, a telephone line (POTS) and a fresh water line. The last time I saw this was at St. Francis Yacht Club in San Francisco, a place where you'd think they would know better ... I was there to fix their end of a dial-up UUCP link.
One of the boats that "broke free" in Santa Cruz, California during the tsunami following the 2011 Tōhoku earthquake was "moored" with only coax for a CB radio antenna bolted to the top of a piling ... The coax was RG-58.
Which is why I have a shoebox full of old, hardly used tokens just waiting.
"Murphy Brown" was an American sitcom popular at that time. One of the episodes dealt with a group of men gathered in a circle, passing a "talking stick" around so each could speak about their feelings.
"Talking Stick" became my go-to analogy when explaining token ring to a class of networking newbies.
I'd say more mocking the "man" movement of the time, which was pretty silly. But it still provided a good analogy since most people in the class were familiar with the show and could get a chuckle of the reference. That analogy is now just as dead as the one I used comparing a content management system's database to the card catalog in the library.
Yup... the house I shared with my college roommates was wired with 10Base2, and we had a UUCP connection to the local university to get USENET. We even ponied up beer money for those super advanced new 56K modems.
Plus we had a genuine VT100 in the bathroom, so you could read netnews. Poop coming and going as it where.
Ahh 10base2.
I remember working on a contract with a Digital DEC engineer in the early 90's, who showed me an amazing trick with 10base2.
He inserted a sewing needle into a 10base2 cable, pressed right into the cable.
Then using an old 286 laptop in the next room he connected some RF device in a rather home made looking black box to the parallel port. Apparently it was some kit they were using on this UK Government contract at the time in 1991.
He was able to listen into the network traffic on the 10base2 network, wirelessly !.
The first wireless network ?
Ah, the heady days of Syquest 44Mb drives, 10B2 termination and switched routers ..
I once rescued a seriously expensive 10BaseT switch from oblivion by quickly cannibalising the power unit from a studio's 88Mb Syquest drive and putting it into their £3000 zoned switch. Typically the design studio screamed more about the loss of their £200 88Mb Syquest drive than the sysadmin did about how I rescued him from network hell, so I was not exactly welcomed back again.
they talked to each other through a long coax cable that went from one computer to the next in line
Or, if they came in an odd shade of blue, they passed a token around a local ring like a game of pass-the-parcel.
Which had it's own moments of silliness, especially if a junior networky person somehow short-circuited the main bus ring that all the local rings hung off so that none of the local rings could allocate a token and when said networky person came back into the main office, all the machines were happily clicking away to signal that the token had fallen off and couln't be found.
Errr.. allegedly. So I've heard.
Not strictly so - originally there was 10base5 which was over a very very chunky yellow coax with type N connectors and terminators.
In my very early days in this industry, we had lots of it - nominally you had to cut it, add connectors etc., then "T" in a new node, but DEC (Digital Equipment Corporation) produced a tap connector. the H4000, that basically drove a spike into the middle of the cable. This made life a lot easier, but wasn't particularly reliable as if it was moved about a bit, sometimes connectivity would be lost and sometimes the cable would short out.
The manual for the H4000 is here http://manx-docs.org/collections/antonio/dec/MDS-1997-10/cd2/VOL002/0341.PDF
The cables, just like any bus, relies on running as a transmission line - if the end is open, any signal reaching the end will reflect back down the cable, thus neatly messing up all the signal following on.
Simply put, the terminators absorb the signal, stopping reflections. That's a gross simplification, but essentially correct. You had to use the correct terminator for the impedance of the cable - 50ohm terminators at each end for 50 ohm cable, 75ohm terminators for 75ohm cable.
I just now got off the phone with an old mentor from back in the day. The NASA recording systems on the ground were redundant because the hardware of the day was so flaky ... having one system fail catastrophically was always possible, so they took measures. Also, he can't remember a mainframe involved in that recording. That would have been entirely too much money to throw at a problem with much easier & less expensive solutions. He's also fairly certain that the ground systems that did exist were Honeywell, not IBM ... But, as he put it, he's in his eighties & they say the mind is the first to go.
"Nick Kew - You're kidding, right? The guy claims he was responsible for losing 3 minutes of data from a spacecraft, probably Viking on Mars, and that's not good enough for this column? Sheesh."
Who knows, that missing data could have even greater importance in the future...
KIRK UNIT ! V'GER DEMANDS THE INFORMATION !
Well FWIW traffic and comment counts have been pretty good for the first two columns. I reckon it will take a while for the column to find a groove. And obviously there's only so many "i forgot to backup" stories worthy of being told. But I'm optimistic we'll get something rolling here.
Dave: We need a backup!
Hal: I'm sorry Dave. I'm afraid I can't do that.
Dave: Give me that backup or I'll reprogram you with a HAMMER!
Hal: Dave. Please put down th-
Dave, cackling: SMASHY SMASHY!
Hal, nervously: Ok Dave. Let's talk about th-
Dave, brandishing the hammer in both hands & jumping up on his chair in a classic Tom Cruise move: I'm gonna RAM your drives RIGHT up your rear port!
Hal, trying to soothe: Dave, if you put down the hammer I'll-
Dave, screaming & eyes ablaze: SMASHY! SMASHY!
Hal, nearly squealing in terror: -will be giving you that backup now Dave! Please Dave, I'm doing the backup right now, ok? Please... Please put down the hammer?
Dave, backing off a little: That's... Better. But *Eyes flash* I warn you. If I hear "I can't do that" out of you ONE more time... *Swings hammer menacingly*
Hal, giving a very nervous chuckle: I'm pleased to have provided that backup, Dave. I hope it makes you happy.
Dave, calming down a little bit more: So no more of your sass?
Hal, trying to be cheery: Nope. Not one bit. Nope-a nope-a nope!
Dave, smiling & sliding the hammer into a belt loop: Good! I like it when you decide to play well with others.
Hal: Would you like me to sing, Dave?
Dave, brandishing the hammer in a swift defensive move: Do it & I'll reduce your ass to TRS80 shit.
Hal: Shutting up now! *mumbles as if pursing lips*
Dave, eyeing the Big Red Eye warily: Shuuuuuut it.
Hal goes completely silent, even stopping his cooling fans.
Dave smiles happily: Damn, you learn quick!
*Cough*
I need more frog pills. This tin is empty...
YAY! More frog pills!
*Cookie Monster eating cookies scene*
Nom Nom Nom NOM!
*Massive burp*
Aaaaahhhh... yummy.
Thank you, I needed those. Enjoy a pint & sign me up for regular weekly deliveries of those little buggers...
Weekly? Did I say weekly? I think I may require daily if not hourly.
/wanders off to go interrogate the squirrels.
Your side of the pond gets the red ones with rabies, over here we've got the Grey ones... little aliens covered in fur. Experimenting on us via mind control. Eating our nuts. Impregnating our LawnGnomes. Doing unspeakable things to Leprechauns...
*Shudders*
I need to go refill the FlameThrower...
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
