Page "Atanasoff–Berry Computer" Paragraph 12

The memory of the Atanasoff – Berry Computer was a pair of drums, each containing 1600 capacitors that rotated on a common shaft once per second.

The capacitors on each drum were organized into 32 " bands " of 50 ( 30 active bands and 2 spares in case a capacitor failed ), giving the machine a speed of 30 additions / subtractions per second.

Data was represented as 50-bit binary fixed point numbers.

The electronics of the memory and arithmetic units could store and operate on 60 such numbers at a time ( 3000 bits ).