Developer given Mission:Impossible - fixing rubbish code that could crash a city - simply chose not to accept it

ON CALL Making it through a working week can feel like a dangerous adventure.

That's why The Register offers a little certainty and safety by always using Friday morning to share a new edition of On Call – the reader-contributed column sharing your tales of tech support.

This week, meet a reader we'll Regomize as "Socrates," who many years ago was the "fresh-faced manager of a small software department." Socrates' employer had sold some monitoring hardware to a client that made equipment for power stations, but whoever installed the system had neglected to document it properly.

Socrates' boss asked him to visit the site and bring the client up to speed.

"In those days I considered myself to be a bit of a programming hot-shot, and a visit to a power station sounded really interesting, so off I went," Socrates told On Call.

He therefore drove to the plant, presented himself at the security gate, and was eventually led to something called a "turbine overspeed detector." "This power station was seriously big and impressive; massive rotating machines humming away, with barely anyone around," Socrates wrote.

"In a dark remote corner, there it was, the equipment I had come here to see: a dusty CP/M computer with various I/O cards, connected to wiring that snaked off into the far distance." But Socrates had no idea what it did.

In his email to On Call, Socrates pointed out that at the time of this story, Tom Cruise was yet to appear in a Mission:Impossible movie, and The Matrix was still years from release.

But his memory of these events is is somehow entangled with both franchises.

"I didn't know much about electricity generation, but I did know that a turbine is a thing with pointy blades, that are pushed around by steam to drive a generator," he wrote.

"And these turbines were absolutely enormous, and the thought of them overspeeding was truly scary." "You know the scene in Mission:Impossible where Tom Cruise is on the back of a train, pursued by a helicopter that crashes with its rotor blade just inches from Ethan Hunt’s throat?" he asked.

"That image would have been uppermost in my mind; knife-like turbine blades being ejected in all directions, requiring all my Matrix-like skill to dodge them as they headed my direction." He then reasoned that an overspeed event would probably shut down the turbine – before imagining cascading faults blacking out an entire city.

Keen to avoid either scenario, Socrates sat down at the keyboard, opened the relevant software, and vowed not to break anything.

He got into the code and found it was "horrible." "Despite my tender years, I'd gained some exposure to well-structured programs, and this was truly awful," he told On Call.