Computer glitch

On reading your obituary of Walter Stibbs (24 April), I was reminded of when he brought the first main-frame computer to St Andrews University in 1964. It allowed physicists like me the option of X-ray crystallography as a PhD programme.

However, the IMB 1620 had only been invented five years before and was ominously marketed as an "inexpensive" scientific computer. Its use was restricted to undergraduates during the day and it drove those of us who spent our long nights on the monster completely bonkers.

It was generally referred to as Cadet, meaning "Can't Add, Doesn't Even Try", referring to the use of addition tables in memory rather than dedicated addition circuitry.

After three years, I finally completed my physics PhD in 1969 and immediately departed for a career in international business, journalism and eventually the church. It took about quarter of a century before I could bring myself to sit down again at a computer.

DR JOHN CAMERON

Howard Place

St Andrews, Fife