<architecture> A term describing a computer architecture based around an ALU, registers, and data bus which are 64 bits wide.
64 bit processors are quite common in 1996, e.g. Digital Alpha, versions of Sun SPARC, MIPS, IBM AS/4000. the PowerPC and Intel are expected to move to 64 bits at their next generation - PPC 620 and Intel P7.
A 64 bit address bus allows the processor to address 18 million gigabytes as opposed to the mere 4 gigabytes allowed with 32 bits. There are in 1996 already hard disks which can hold over 4GB. Floating point calculations can also be more accurate.
A 64 bit OS is needed as well to take advantage of the CPU. In 1986 there are only a few 64 bit operating systems, including OS/400, Digital Unix, Solaris (partialy). A 32 bit OS can run on a 64 bit CPU.
(23 Dec 1996)