I did some research. A byte is 8 bits in length, and a word is the smallest unit of memory that can be addressed. A word's exact length varies. On early computers, including the Intel 8080, a word was always 16 bits long. So, no, 8 is not a valid word size. However, it is a common value for the addressable space of memory on modern computers. 4, 6, and 9 are also common values for memory address sizes.