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IT blooper #48: Why Nudger blames McDonut

In this true story, the graveyard shift takes its toll on a donut fanatic.

Way back when mainframes ruled -- think late '80s -- two IT guys sat in a gray room all night under a buzzing and constantly flickering fluorescent light. Their mission: to make sure a major bank's overnight processing batch run ran smoothly.

The innocent party of this duo, let's call him "Nudger," relates the story of a co-worker's big blunder. Nudger calls the blooper perpetrator "McDonut," a nickname based on the latter's penchant for tasty pastries. Besides leaving sticky fingerprints everywhere, McDonut confused the numbers one and zero and rocked the pair's binary world.

The blinking fluorescent light barely illuminated Nudger and McDonut, who were poised to spring to action whenever the mainframe's green blinking lights changed to red.

Zoom to the innards of the mainframe, where all the day's withdrawals and deposits were being processed. A standing orders/direct debit application suite contained a huge input file containing records such as "from account," "to account," "amount to pay" and so on. Also in this particular application was a numeric flag bit, which determined the immediate future of a record. A "1" meant the record would be processed, whereas a "0" meant it would not.

The routine "3 a.m. cowboy fix" for a failure was to examine the dump output, locate the dodgy record, set the processing bit to zero and rerun the job. Alas, there was no GUI back then, so all commands had to be typed out. The command to change the bit was something like "c 1 0 recnum colnum." "Recnum" was the record number, and "colnum" was the bit number.

One night, the job crashed and Nudger and McDonut jumped into action. Perhaps McDonut was dazed by lack of sleep or an overdose of sugar. Whatever the cause, he forgot to type in the location of the one faulty record and to use the right bit number. Instead, he typed a command that changed all the ones to zeros on all files!

Once the deed was done, McDonut came to his senses. He realized his hasty mistake and stopped the process before saving and rerunning.

Alas, Ctrl-Z was a just twinkle in someone's eye at this point in time. Lacking a one-command cure-all, McDonut tried to undo his error by repeating the global change and replacing all the zeros with ones.

Now, Nudger could have told his co-worker that this second global change would not undo the error. But McDonut didn't ask, and he didn't remember that. So he saved and ran the input file with the incorrect command.

The day shift arrived to find a mess of faulty and missing reports. To untangle the web McDonut weaved, they had to enter hundreds of reversals to incorrectly paid transfers. Naturally, they remembered to input the record and bit numbers.

Obviously, McDonut could have used some coffee for dunkin'. Blooper:

Share your bloopers with us. E-mail them to Read more of our past IT Blooper Series, which originially appeared at, part of the TechTarget network.

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