<Dd> IBM delivers the IBM 7030 Stretch supercomputer, which uses 64 - bit data words and 32 - or 64 - bit instruction words . </Dd> <Dd> Control Data Corporation launches the CDC Star - 100 vector supercomputer, which uses a 64 - bit word architecture (prior CDC systems were based on a 60 - bit architecture). </Dd> <Dd> International Computers Limited launches the ICL 2900 Series with 32 - bit, 64 - bit, and 128 - bit two's complement integers; 64 - bit and 128 - bit floating point; 32 - bit, 64 - bit, and 128 - bit packed decimal and a 128 - bit accumulator register . The architecture has survived through a succession of ICL and Fujitsu machines . The latest is the Fujitsu Supernova, which emulates the original environment on 64 - bit Intel processors . </Dd> <Dd> Cray Research delivers the first Cray - 1 supercomputer, which is based on a 64 - bit word architecture and will form the basis for later Cray vector supercomputers . </Dd>

What is the size of the accumulator of a 64bit processor