rockwell 330

this is a very natty desk calculator. it displays and calculates to 14 digits. see here sqrt(99).

it functions like most desk calculators, where the plus button is predominant and = is only used for * and /

there are two memories I and II. when used small annunciators appear on the left of the display.

the left side of the keyboard offers a generous array of memory operations. you can add or subtract the current number to memory within an operation (M+ and M-)

or you can complete the operation and add or subtract the result from memory (=+ and =-)

also a switch offers a tally mode into either memory1 or 2 similar to other such machines. rather than having a digit switch for 2, 3 or 4 decimal places, you can set this number with the DEC SET button and a switch is used to specify the rounding mode.