IAS
1. <computer> The first modern computer.
It had main registers, processing circuits, information paths within the
central processing unit, and used Von Neumann's
fetch-execute cycle.
The IAS machine's basic unit of information was a 40-bit
word and the memory had 4096 words.
A word stored in memory could represent either an instruction or data.
Each IAS instruction was twenty bits long, so that two instructions could be stored in each 40-bit memory location.
Each instruction consisted of an 8-bit
operation code and a 12-bit address that could identify any of 2^12 locations that may be used to store an
operand of the instruction.
The
CPU consisted of a data processing unit and a program control unit.
It contained various processing and control circuits along with a set of high-speed registers for the temporary storage of instructions, memory addresses, and data.
The main actions specified by instructions were performed by the arithmetic-logic circuits of the data processing unit.
An electronic clock circuit was used to generate the signals needed to synchronise the operation of the different parts of the system.
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2. Immediate Access Storage.
