* Posts by swm

551 posts • joined 6 Jun 2015


I got 99 problems, and all of them are your fault

swm Silver badge

Re: Wibbly

"her monitor has a proper shimmy on"

At work our group was moved to a couple of trailers during some remodelling work. Most of the CRT computers exhibited a shimmy. We noticed 4 amps through the safety ground. Further checking finally revealed a bad ground wiring in one of the fluorescent lights. Lots of tracing with a clamp ammeter and magnetic field detector.

Wrap it before you tap it? No, say Linux developers: 'GPL condom' for Nvidia driver is laughed out of the kernel

swm Silver badge

In the early days of time sharing Dartmouth got a time sharing system working on a GE-225/DN-30. The hardware was upgraded to a GE-235/DN-30 system that was 3 times faster. It also had more instructions. So, of course, the person writing the GE-235 exec used these extra instructions.

Since this was all on an NFS grant, GE took the software and sold it to customers. But the software no longer worked on a GE-225. So they sold the customer a GE-235 with a wait loop in the exec to slow down the machine. This code was clearly marked. The customer was happy - they got what they wanted at the quoted price.

It was fairly common in the 1960's to ship a computer with many instructions disabled. For a price, wires were cut that disabled certain instructions.

The IBM 1401 had an instruction "read tape binary" that required extra money. But the diagnostics required this instruction so all 1401's had this instruction - paying extra money to enable this instruction caused no changes to the hardware.

We had a 407 accounting machine we used to list cards. It ran at 100 cards per minute. I noticed a couple of relays that were disabling every third cycle. removing this relay caused the machine to print at 150 cards per minute. I told this to the customer engineer and he said, "Yes, but you are paying for a 100 card per minute machine." So I left the relay in place.

A tale of mainframes and students being too clever by far

swm Silver badge

"It was a real-time BASIC program - and the user had decided to add a subroutine starting at line 1000000."

The original BASIC only used a maximum of 5 digits for the line number. Users using longer line numbers were continually surprised at the results:

Deleting line 123456 wouldn't work - you had to delete line 12345 etc.

swm Silver badge

Re: Clearing storage may not be good for you

I believe that on an early version of MULTICS some programmer cleared a large array by columns instead of rows. This caused a page fault for just about every memory access.

On the IBM 1620 using FORTRAN copying the value of one uninitialized variable to another variable would sometimes clear all of memory because the flag on the uninitialized variable wasn't set so it would copy until it hit a digit with a flag set. But all of the set flags were cleared out by the copy so it never stopped. A program like:

I = J (J not initialized)

(depending on the order of I and J in memory) was all that was needed.

The IBM 704 had a clear memory button that was active only when the machine was running!

'I'm telling you, I haven't got an iPad!' – Sent from my iPad

swm Silver badge

Re: Denial is the first defence.

Although, when I worked at Xerox, I designed and built a laser printer driver for a new product. The developers claimed I was sending a bogus character so I put in microcode a logger that logged every character sent and received. Nope, no extra characters.

So I went to the developers lab using my hardware and software and they had put a terminal in parallel with the laser printer. Sure enough, there was an extra character. After some head scratching i noticed that the character was sent when the software terminated. A few minutes later I discovered that resetting the UART was causing the extra character to be sent (after my microcoded logger had shut down). Easy fix was to output a MARK before resetting the UART.

Sometimes the customer is right and it pays to keep an open mind.

swm Silver badge

When i was teaching computer science we would run all submissions through a "cheating checker". It would compare every submission against every other submission and print out the top 15 high scorers. I remember one pair of submissions (which were quite lengthy) where the "diff" output was less than a page consisting of the student's name and class number.

Another time two students in my sections got the high score on this cheating checker so I printed out both submissions and discovered that they were using totally different approaches to solving the problem. Copying wouldn't have done them any good - but why the high score? I looked at the raw data and discovered that the checker ignored the contents of strings and that it had matched up many "System.out.println()'s". Oh well.

swm Silver badge

Re: On helpdesk calls

I could diagnose, with a 200 MHz oscilloscope, an unplugged machine in under 3 hours.

swm Silver badge

Re: Which is why I always turn off email sigs...

At the college where I taught one of the professors had a sig with 20 lines of "do not forward, check with your attorney etc.", followed by even more bizarre cautions, warnings, threats etc. It was a total spoof of the required sig that the university insisted on.

Are you sitting comfortably? Then we'll begin. Hang on, the PDP 11/70 has dropped offline

swm Silver badge

Re: Those were the days.

I miss the blinken lights and switches. I debugged an operating system with them around 1968.

swm Silver badge

Re: Front panels and security keys...

I was working in the college computer center about 2 AM around 1970 over the Christmas break. I was the only one in the building except for the operator. I heard a funny "clunk" and was puzzled as to what it could be. I investigated and discovered the operator lying in a corridor breathing but otherwise totally unresponsive. Who to call?

I called the campus police who arrived quickly in their cruiser. The campus policeman said to get the stretcher from the cruiser. While I was fiddling with the stretcher a dean of the college, walking home, spotted me and thought I was ripping off the cruiser. I figured the best way to get him to hurry was to ignore him. When he showed up I told him he could carry the other end of the stretcher into the building. The operator was carted off to the hospital about a block away.

Then we discovered that the operator had all of the keys on his person and we had to do some fast talking to get the keys out of the hospital safe.

The operator had had a stroke that was so sudden that he fell, bumping his head on the wall on the was down. He did recover fully though.

swm Silver badge

Re: Clean Agile Development

There was a janitor in the computer center (a very nice guy) who cleaned off the director's whiteboard. He was politely told never to clean a whiteboard in the building. He was just trying to do a good job.

Russia tested satellite-to-satellite shooter, say UK and USA

swm Silver badge

"Interesting, the object had around the speed of an airgun slug so to do any damage would need to have a bit more mass."

Actually, you only have to aim at something in a different orbit and you might have many miles per second velocity difference when it hit the target. Just launching ball bearings straight up to intersect a satellite would result in lots of damage.

What evil lurks within the data centre, and why is it DDoS-ing the ever-loving pants off us?

swm Silver badge

Re: That said

On the old telephone 4A crossbar office (a telephone router with no subscribers) they had metal cards to control the routing of calls in and out of the exchange. They once had incorrectly punched some metal cards and caused a routing loop that tied up all of the lines from Chicago to Milwaukee.

Shocked I am. Shocked to find that underground bank-card-trading forums are full of liars, cheats, small-time grifters

swm Silver badge

I always wondered about 89724102172714182892114I7551670349743096734346773478647892349863592355648544996312855148587659264921 so (after changing the I to a 1) I found the (4) factors:

393649 657481 × 6335 348305 575195 179179 076633 × 69466 777282 071413 430494 981273 × 51 790677 862630 192029 633722 348449

Your welcome.

VMware to stop describing hardware as ‘male’ and ‘female’ in new terminology guide

swm Silver badge

Re: This PC subversion only idiotically makes things harder and more confusing for competent people

Absolutely not: for that, there are "lesbo adapters"

There are hermaphroditic connectors.

swm Silver badge


If you want to design and make your own 5nm high-end system-on-chip, Marvell's offering ASIC-as-a-service

swm Silver badge

5 nm - Wow!

The title says it all.

Cisco restores evidence of its funniest FAIL – ethernet cable presses switch's reset button

swm Silver badge

Re: Who buys those cables?

I once saw a couple of operators working a cord board exchange. You wouldn't believe the complexity of the cable tangle. The operators would be gossiping while interrupting with "Number Please." They would occasionally have to carefully unthread a cable to tear down a connection.

If you can read this, your Windows 10 2004 PC really is connected to the internet no matter what the OS claims

swm Silver badge

Network problems for MICRO$01 apps

So, let me get this straight: The network works fine but MS data slurping doesn't work.

What is the problem exactly?

Mainframe madness as the snowflakes take control – and the on-duty operator hasn't a clue how to stop the blizzard

swm Silver badge

Back in 1965

The Dartmouth Time Sharing system went on line in 1964. It was financed with an NSF grant which meant anyone could have the source code. GE cloned the system and started selling commercial time sharing. We (college students) thought it was unfair that no one in the college got credit so we hacked their system, set up another account etc. There was a field I didn't understand in the accounting record which I assumed granted permissions. So I set all of the bits to one. Turns out it was an accounting field keeping track of "A" time, "B", time, and "C" time. There was no B or C time but when they ran their monthly accounting our bogus account had accumulated B and C time.

Then there was the time that the college employed student workers in the data center. This stopped when one of the workers flunked his roommate, And it was discovered that Nikita Khrushchev was enrolled in three freshman seminars.

At the Palo Alto Research Center they brought up a new machine and needed everyone's password. Rather than asking everyone they used a net sniffer that got 99% of the passwords to load into the new machine.

Oh sure, we'll just make a tiny little change in every source file without letting anyone know. What could go wrong?

swm Silver badge

Re: Mail Storm

As in "Desk Set".

swm Silver badge

Re: Ratelimiting

Our sysadmin at college had a tar pit for spam mail. For selected senders he would set the maximum packet data length to one byte (which really slowed them down). After receiving the email it would be rejected with a code to resend it.

His theory was that he was tying up resources of the sender as a public service.

Talk about rate limiting.

You're testing them wrong: Whiteboard coding interviews are 'anti-women psychological stress examinations'

swm Silver badge

Re: Whiteboard coding - never done it, never ask anyone to do it

When I was in college writing an executive I would sketch out ideas on a huge blackboard in my office. Yes, a real blackboard of Italian slate with white chalk. A real blackboard has a great tactile feel. If there was any code it would be a short sequence of instructions to see if the sequence was optimum. The actual code was written on backs of listings or other scraps of paper. I would then keypunch it onto cards and assemble it.

I would never let anyone else keypunch the code as this was my final check and I discovered many errors while keypunching.

MariaDB inhales $25m. 'People tried to get away with simpler' but now there's a 'relational renaissance,' says open-source biz chief

swm Silver badge

Re: Overkill?

I love SQLite. When I had to maintain a website for thousands of square dances etc. I thought I would learn SQL for the fun of it. So I put all of the information in an SQLite database and generated web pages from the database.

Best decision I ever made. If something needs to change or page headers need to be replaced I just modify the appropriate place in the database and regenerate the website. When one of our round dance cuers got married I changed one entry and, presto, everywhere she showed up on the website was changed.

The reluctant log trawler: The buck stops with the back-end

swm Silver badge

Re: Bodging someone else's cock-up

When we were writing the Dartmouth Time Sharing System there was one programmer that churned out voluminous amounts of buggy code. There was another programmer that didn't like to write code, just find and fix bugs.

When we discovered this we just put the second programmer on the trail of the first and produced lots of debugged code.

NASA trusted 'traditional' Boeing to program its Starliner without close supervision... It failed to dock due to bugs

swm Silver badge

Re: History repeats...

"Anyone remember NASA not doing a full up integration test of Hubble before it was launched?"

I believe that the main mirror of the Hubble telescope was figured with very precise laser interferometric testing. Unfortunately there was a .01" in the dimension of part of the test setup. This was cross checked with a knife edge test that showed the error but, since the laser interferometer was much more precise, it was assumed that the laser interferometer was correct.

You really can't do a "full up integration test" on this kind of system.

Cool IT support drones never look at explosions: Time to resolution for misbehaving mouse? Three seconds

swm Silver badge

TTY fix

When model 35 TTY's were used to connect to time sharing mainframes our head secretary got a call from a user. She heard a loud buzzing noise in the background caused by low paper in the TTY so she said press the "buzzer release" button on the far left to stop the noise so they could talk. The buzzing stopped and she asked the user what the problem was. The user sheepishly said, "That was the problem."

swm Silver badge

That's why medical electronics generally have rounded tops - otherwise something squishy and drippy would be placed on top.

Boffins baffled as supergiant star just vanishes – either it partially blew itself apart or quietly turned into a black hole

swm Silver badge

This is Serious

People are joking about this but wait until it is our turn. We have to take action now before it is too late. Let's put a defensive perimeter around as many stars we can (especially our sun) and track down the perpetrators before they steal an entire galaxy.

Finally, a wafer-thin server... Only a tiny little thin one. Oh all right. Just the one...

swm Silver badge

Re: Partial blackout story (not UPS, though)

I was sitting at home when it felt like a really heavy truck was passing and the lights dimmed a couple of times. I thought a truck had run into an electrical pole. Turns out a few railroad cars were dropping off of an elevated track a few blocks away taking out power wires, crushing parked cars etc., and narrowly missing a car driving under a railroad bridge. Fortunately, no one was injured or killed.

Faxing hell: The cops say they would very much like us to stop calling them all the time

swm Silver badge

Re: Way back when...

A lot of the old strowager exchanges had a mechanism to "absorb digits. In one exchange with 60,000 subscribers) dialing "2" would just be ignored; dialing "4" would also be ignored but would take the next digit (even 2 or 4). So dialing 242-xxxx would result in 2 (ignored), 4 (ignored but prime for the next digit), 2 (would actually step to the second level and go on to the next bank of switches).

This could cause connections to numbers only loosely related to what was dialed.

I actually saw this exchange (I think in Albuquerque, NM, about 50 years ago) and it was an amazing sight and sound. Continuous clickity-clacks and alerts etc. Amazing that they could keep this acre of equipment working.

A memo from the distant future... June 2022: The boss decides working from home isn't the new normal after all

swm Silver badge

Re: New Normal?

Then there are the managers who object to side conversations: "Let's have only one meeting here."

swm Silver badge

Re: New Normal?

A physicist, engineer, and a mathematician examine the statement that all odd numbers are prime.

Physicist: 3's a prime, 5's a prime, 7's a prime, 9 - experimental error, 11's a prime, 13's a prime - all odd numbers are prime.

Engineer: 3's a prime, 5's a prime, 7's a prime, 9 - well, 9 is the exception, 11's a prime, 13's a prime - all odd numbers are prime.

Mathematician: 3's a prime, therefore, by induction, all odd numbers are prime.

Someone got so fed up with GE fridge DRM – yes, fridge DRM – they made a whole website on how to bypass it

swm Silver badge

Re: Advertent FUD

"Most tapwater in the US is good quality."

Tell that to the residents of Flint Michigan. The government actually hid problems with their water quality.

'One rule for me, another for them' is all well and good until it sinks the entire company's ability to receive emails

swm Silver badge

Re: Out of Office...

Mail on the original ARPANET had a problem with two people responding to "out of office" messages with "out of office" messages (ccing all of the other recipients). Things filled up fast until protocols were developed not to respond to automatically generated messages.

Developers renew push to get rid of objectionable code terms to make 'the world a tiny bit more welcoming'

swm Silver badge

Re: Then, there is Chess...

Black goes first in GO.

Ooo, a mystery bit of script! Seems legit. Let's see what happens when we run it

swm Silver badge

Re: Not quite the same...

"Similar vintage a friend got the Fortran control characters wrong so it threw a new page instead of a new line."

This was quite common as the first column was generally used as a page control. If there was a number there it could cause this one line per page problem. Or even worse, overprinting on the same line until the paper tore through.

Have I Been Pwned breach report email pwned entire firm's helldesk ticket system

swm Silver badge

It looks like the help desk software is to blame by not cleansing the ticket data. Fixing the source of the bad data is not a solution.

Hooray, space boffins have finally got InSight lander's heat probe back into Martian ground again

swm Silver badge

I hope they haven't hit a rock.

80-characters-per-line limits should be terminal, says Linux kernel chief Linus Torvalds

swm Silver badge

Re: not the terminal, the punch card

"Cutting eight characters to four and allowing lines to go longer allows you to keep these sources of bugs at bay."

I actually use 2 spaces per indent. But then again it is my code. I will follow coding standards for any group project.

swm Silver badge

Re: not the terminal, the punch card

The 72 character limit was due to the fact that the IBM 704 could read only 72 columns. Many IBM card applications used all 80 columns.

Boffins step into the Li-ion's den with sodium-ion battery that's potentially as good as a lithium cousin

swm Silver badge

In high school we squirted HCl acid onto pieces of sodium and it made little fireballs.

Microsoft's carefully crafted Surfaces are having trouble with its carefully crafted Windows 10 May 2020 Update

swm Silver badge

Windows XP

I had a windows XP machine that was rock solid for 15 years. Last month one of the drives stopped working so I debated getting the machine repaired. However WINE ran all of my XP programs I needed on my UBUNTU machine so I think I will not bother fixing up the XP machine. I then discovered that my XP software ran considerably faster under WINE (because of a faster processor) so I am abandoning the XP machine.

I have a windows 10 laptop and am currently trying to figure out how to stop all updates.

They've only gone and bloody done it! NASA, SpaceX send two fellas off to the International Space Station

swm Silver badge


Not only did the launch go perfectly but the main booster landed perfectly! Wow!

Software bug in Bombardier airliner made planes turn the wrong way

swm Silver badge

Re: At least..

In the late 1960's a NE Yellowbird flight into Lebanon, NH, came into a VOR landing. The airspace was protected out to 10 miles from the VOR as specified on the charts. Unfortunately the pilot made his turn 12 miles out and clipped the top of a mountain. Everyone died.

So you really didn't touch the settings at all, huh? Well, this print-out from my secret backup says otherwise

swm Silver badge

Re: Ah, customers.

'As my grandmother would have said, "Them as can, do. Them as can't, teach."'

I heard this as, "Those that can't learn, teach. Those that can't teach teach teachers."

Referring to the public school system.

Linus Torvalds drops Intel and adopts 32-core AMD Ryzen Threadripper on personal PC

swm Silver badge

Re: Minimum spec?

Xerox wrote their STAR office products using the XDE (Xerox Development Environment). The development environment was blazingly fast but the actual user code was abysmally slow because the developers never used it.

Dude, where's my laser?

swm Silver badge

Re: Not unbelievable

At Dartmouth the physics department in the 1970's would use Baker Tower as a target for their ruby lasers. They would chip paint off of the tower from >100 yards.

Microsoft drops a little surprise thank-you gift for sitting through Build: The source for GW-BASIC

swm Silver badge

Re: Only 45 years late?

I remember writing a Z80 simulator (in Sigma-7 FORTRAN) and running MS-BASIC on it. It worked but was very slow. This was about the time of the ALTAIR computers. One problem was turning the paper tape object code into a file.

A real loch mess: Navy larks sunk by a truculent torpedo

swm Silver badge

Re: Oops!

During WW2 my father was commander of a submarine base in Australia. He had complaints of torpedoes that would do a 360 and "whoosh" over the firing sub. Turned out that it was due to poor training/maintenance which locked the gyro so the torpedo would make a hard right or left rudder after launch. The technical details of the poor maintenance are interesting but too long to report here.



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