Von Neumann and his colleagues began the design of a new stored program computer, referred to as the IAS computer, at the Princeton Institute for Advanced Studies.

It consists of

• A main memory, which stores both data and instructions

• An arithmetic and logic unit (ALU) capable of operating on binary data

A control unit, which interprets the instructions in memory and causes them to be executed. Input and output (I/O) equipment operated by the control unit.

The memory of the IAS consists of 1000 storage locations, called words, of 40 binary digits (bits) each. Both data and instructions are stored there. Numbers are represented in binary form, and each instruction is a binary code each number is represented by a sign bit and a 39-bit value.