In about 1979 I was working in the EDP department of Karstadt, at the time Germany's largest department store. We were introducing a new on-line order system for furniture, based on Tandem Computers technology.

At the time, the Tandem development software was not overly comfortable. Error messages from all utilities were just numbers. For example, FILE SYSTEM ERROR 011 meant “file not found”.

So I wrote a little library function to patch into the binary of each utility to produce sensible error messages, and stored the messages in an indexed file.

That meant that I also had to write a little utility to maintain the file. Early one morning, while testing it, and feeling a little silly, I entered “Please enter FUP PURGE ! *” (the equivalent of Unix rm -f *) as the description for error 11.

While I was still giggling, the project manager came to me. “Mr Lehey, I think I've done something silly”.

Fortunately, we had good backup processes in place, and nothing was lost. But it reminds me how easy it is for people to follow instructions from computers, even when they know better.