Tru64 UNIX is a discontinued 64-bit UNIX operating system for the Alpha instruction set architecture (ISA), currently owned by Hewlett-Packard (HP). Previously, Tru64 UNIX was a product of Compaq, and before that, Digital Equipment Corporation (DEC), where it was known as Digital UNIX.
A Digital UNIX key chain. The other side reads, "CALIFORNIA - Y W8 4 HP - The Migration State"
Digital Unix distribution media
In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, address buses, or data buses of that size. A computer that uses such a processor is a 64-bit computer.
Hex dump of the section table in a 64-bit Portable Executable File. A 64-bit word can be expressed as a sequence of 16 hexadecimal digits.