Hide the keyboard – it's the only way to keep this software running

On Call By the time Friday rolls around, The Register understands readers might just want to toss the rest of the working week away without a care for the consequences. That sense of ennui is why we ease you into the last day of the working week with a new instalment of On Call, the reader-contributed column that celebrates the sometimes-silly side of working in tech support.

This week, meet a reader we'll Regomize as "Henry" who told us of a job he held in the 1980s at a small electronic engineering company that made and wired up "thundering great control panels for the gas industry."

"Think loads of dials and buttons all eventually controlling machines," Henry urged On Call.

By the time he got this gig, software had also become part of the mix – in the form of a Turbo Pascal package that could read the data from all those dials.

"We supplied and installed the equipment at a gas pumping station and all was going swimmingly," Henry recalled. "Everything was tested and signed off, the software swung into life, and gas started pumping. We headed home for some congratulatory beverages."

The party didn't last. Two days later the system was down and Henry was asked to fix it.

Restarting it proved easy, but the cause of the outage was elusive. Log files recorded no anomalies – just a final message at 5:57 AM.

Henry wrote it off as just one of those things. But then it happened again the next day, just a couple of minutes earlier. Again, the fix was easy, but no cause for the outage was evident.

Nor was it when the app again went down at around the same time next day.

Henry was therefore dispatched to visit the client and roused himself at 5:00 AM so he could observe operations at the time the crashes had occurred.

As the clock ticked past 5:50 AM and the software kept running, the gas company's next shift of workers arrived and Henry made a mistake – in the form of a cup of tea for one of the new arrivals. We say it was a mistake because, while he was brewing up, the system went down again.

Which left Henry having to explain to his boss that yes, he had been on site, but no, he wasn't watching at the relevant time.

At least the fix was again easy.

• Your computer's not working? Sure, I can fix that problem – which I caused
• Yes, your network is down – you annoyed us so much we crashed it
• Techie took five minutes to fix problem Adobe and Microsoft couldn't solve in two weeks
• OS/2 expert channeled a higher power to dispel digital doom vortex

A more senior colleague was then sent to the site to ensure Henry's eyes didn't wander at the wrong moment.

At 5:30 AM the next day, the two sat down and stared at the relevant kit. Again, workers arrived for the 06:00 shift change.

And one of them tossed their lunchbox onto the desk, where it smacked the keyboard – hard.

And then the system went down – just as hard.

Henry and his colleague rebooted the app, and the gas flowed again.

Then they started mashing keys.

"On the eighth key or so the screen went blank and a reboot was needed," Henry told On Call.

Problem solved? Not quite. "The solution in this case was to buy a piece of Perspex and bend it to cover the keyboard with just enough space to get your hands in and type," he told On Call.

Once that safeguard was in place, a proper investigation yielded the insight that the keyboard was interrupt-driven, and pressing too many keys caused the interrupt buffer to overflow and crash the computer to which it was connected.

"It was not exactly our fault, but still embarrassing," Henry told On Call.

What's the strangest reason for a crash you've encountered? Don't throw your lunch at your keyboard, throw your fingers instead by clicking here to send On Call an email detailing your story, so we can share it on a future Friday. ®