Another working week has arrived, bringing with it the chance to shine or commence career decline. The latter is the sort of thing often writes about each Monday in "Who, Me?" – our reader-contributed column that shares your stories of workplace errors.

This week, meet a reader we'll Regomize as "Mark," who took us deep into computing history because his story comes from his time working at the UK office of legendary mainframe maker Sperry Univac.

Mark told us this was the time of "punch cards and operator scheduling of jobs and prints. Tapes and the big old disk platters." And no monitors – when a program ran, its results were sent to a printer. The inventory job ran in what Mark called "top memory," separate from the shared memory used by smaller workloads. Two printers were in place, so different workloads had their own means of creating hard copy.

One of Mark's duties was working on a weekly inventory job that took five or six days to run, including the time required to print the results. Three managers supervised the important weekly job and, on this occasion, flew in from the US to observe proceedings.

"Once it started printing, the main part of the job was finished and we just had to keep feeding in the 20-plus boxes of paper," Mark explained. His team therefore dedicated one printer to the job.

"It generated (potentially) many more pages than it should have done, and asked if I wanted to print it all," Mark wrote. "I checked with the programmer and was given the OK to cancel the print stage, so I did."

At this point, one of the printers stopped – but it was the printer working on the inventory job, not the lesser workload Mark thought he was killing.

"The output was completely gone. Not even the summary pages survived."

"The rest of my day was spent realizing that the three senior managers from America were unable to do anything until the job completed successfully. Next week."

Mark obviously felt dreadful.

"Everyone was extremely sympathetic and there was no indication of blame," he wrote, adding an ominous "but…"

Have you terminated the wrong process and feared you'd terminated your career too? If so, don't stop until you click here to send your story to Who, Me? ®