64-bit computing 64-bit computing In computer architecture, 64-bit computing is the use of processors that have datapath widths, integer size, and memory address widths of 64 bits (eight octets). Also, 64-bit computer architectures for central processing units (CPUs) and arithmetic logic units (ALUs) are those that are based on processor registers, address buses, or data buses of that size. From the software perspective, 64-bit computing means the use of code with 64-bit virtual memory addresses. However, not all 64-bit instruction sets support full 64-bit virtual memory addresses; x86-64 and ARMv8, for example, support only 48 bits of virtual address, with the remaining
Byte order mark as a byte sequence in various encodings and how those sequences might appear in a text editor that is interpreting each byte as a legacy encoding (CP1252 and caret notation for the C0 controls): Byte order mark The byte order mark (BOM) is a Unicode character, , whose appearance as a magic number at the start of a text stream can signal several things to a program reading the text: BOM use is optional. Its presence interferes with the use of UTF-8 by software that does not expect non-ASCII bytes at the start of a file but that could otherwise