In an overlooked corner of the history of computers, in around 1957 I pioneered the use of a Weetabix box (Letters, passim) to build an adding machine. Two spindles were stuck through near each end of the broad face of the box, with a numbered dial on each and a piece of string inside the box with each end wound around one spindle. Finally, near the middle of the string, a strip (cut from a flap of the box) was attached that poked through a slot in the long, narrower side of the box. When the dials were turned, the strip slid out of the box by an amount corresponding to the sum of the two amounts turned on the dials. It didn’t catch on.
David Chillingworth
Romsey, Hampshire
• When I was a young civil servant in the 1960s, the shoulders being “tapped” (The new MI6: less white and less like Bond, 3 March), never to be seen or heard of again, were exclusively those of people known or suspected to hold strong rightwing views. Let us hope that current shoulder-tapping goes right across the political as well as the racial spectrum.
Robin Wendt
Chester
• While I quite understand that the Guardian’s policy is not to unnecessarily frighten its readers, it is perhaps overly cautious to publish an obituary of the wonderful Betty Tebbs (2 March) without mentioning her Communist politics and membership.
Nick Wright
Media officer, Communist party
• But wasn’t losing all that correspondence (‘Serious harm’ fears in huge NHS data loss, 28 February) just an attempt to achieve Jeremy Hunt’s aim of a paperless NHS?
Penny Aldred
London
• My grandmother, born in Woolwich, migrated to Leeds and then to rural Norfolk, used to bake the blobs of leftover pastry just as they were and offer them warm with butter as “rubbins up” (Letters, passim). Children had to move fast to get any.
Richard Harley
Alresford, Hampshire
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