When I was an undergrad, I spent a year working for Link-Miles (the old flight simulator manufacturer) down on the South Coast of Blighty. I was actually working in the business support section of the company, and my manager had a Commodore PET computer - the more expensive business-class model. This was used to generate various reports for the PHBs.
Some of these reports required over-night runs, which most of the time was not an issue. However once or twice a week we would come in on the morning and find the computer frozen with the report job only partially done. Much head-scratching occurred, and I eventually put together a small program (almost embarrassingly simple) which we could use to work out when the computer was freezing. To our surprise it was at almost the same time every night - about 2:00 in the morning. Cue more head-scratching for the next couple of days, until someone realised that there was a medium-engineering company next door. Light-bulb moment! A quick trip over resulted in us finding that: (a) they had an electrically-powered drop-hammer on the premises, (b) they tended to use it during off-peak hours to save money, and (3) they where currently using it two or three times a week in the early hours of the morning.
It turned out that the drop-hammer was generating voltage drop-outs on the primary mains supply which was serious upsetting the CPU of our PET computer, hence the lock-ups. The subsequent installation of a UPS to regulate the voltage saw the problems magically disappear.
Biting the hand that feeds IT
