Vintage Calculators

[Dave Moll]

The first calculator (other than a slide rule or mathematical tables) I used (at school) was one of those mechanical ones where you set up the number with a set of levers then turn the handle clockwise to subtract it or anticlockwise (counterclockwise beyond the pond) to add.  I can't say I recall the first (electronic) calculator I owned, but have vague recollections of a hexadecimal one at some point, which was useful when debugging computer machine code.