this is an anita 1010 made by sumlock comptometers in
1969. it has a ten digit nixie display and can perform the four basic
operators, percent and rounding to 2 places.
operation follows an rpn style where the first number is keyed in,
"enter number" is pressed, the second number is entered and
finally one of "+=", "-=", "*=" or
"/=" is pressed. the rounding button can subsequently be pressed
to round the result to 2 decimal places.
the keys are gorilla proof and are constructed as individual switches.
the "C" key locks down like an old typewriter caps lock key.