Byte addressing might still need to access 8-bit data over its 64-bit address line, and have the data returned in the bottom 8 bits of its longer data line. Byte addressable memory refers to architectures where data can be accessed and addressed in units that are narrower than the bus. An eight-bit processor like the Intel 8008 addresses eight bits, but as this is the full width of the bus, this is regarded as word-addressable. The 386SX, which addresses memory in 8-bit units but can fetch and store it 16 bits at a time, is termed byte-addressable. Bytes have not always meant
Byte addressing be achieved in one instruction: store this character code at that byte address. Text programs are easier to write, smaller, and run faster. The advantage of word addressing is that more memory can be addressed in the same number of bits. The IBM 7094 has 15-bit addresses, so could address 32,768 words of 36 bits. The machines were often built with a full complement of addressable memory. Addressing 32,768 bytes of 6 bits would have been much less useful for scientific and engineering users. Or consider the 32-bit Pentium processor. Its 32-bit address bus can address 4 billion different items.