Because of the machine's innovative use of electronics for arithmetical calculation, it has been described as the first "electronic digital computer". However, it was a special-purpose, non-programmable "hard wired" machine, which distinguishes it from later, more general machines, such as ENIAC, the Harvard Mark I, EDVAC, the University of Manchester designs, or Turing's post-War designs at NPL and elsewhere.
The machine was, however, the first to implement three ideas that are still part of every modern computer:
The memory 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.
See also: History of computing hardware