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Absolutely not. A byte is the smallest block of memory with an address. E.g you can't take the address of 7 combined bits on x86 but you can for 8. In the

Absolutely not. A byte is the smallest block of memory with an address. E.g you can't take the address of 7 combined bits on x86 but you can for 8. In the past, architectures differed wildly in number of bits per byte, e.g 36 for the machine where the Pascal language was created. Today, the industry mostly standardized on 8 bits per byte, but see e.g the PIC architecture for an example relevant today with a different choice: 8 bit bytes for data, but 10 bit bytes for instructions. https://en.m.wikipedia.org/wiki/PIC_microcontrollers https://en.m.wikipedia.org/wiki/PIC_microcontrollers

cwzwarich 7y ago
> A byte is the smallest block of memory with an address. E.g you can't take the address of 7 combined bits on x86 but you can for 8. I think that's an anachronistic/incorrect usage. A lot of machines (including several with 36-bit words that you mentioned) supported larger basic addressable units of memory, but didn't call these larger units "bytes", and distinguished between "bytes" and "words". In fact, one of the elements of the early RISC philosophy was that CPU support for byte accesses (as opposed to word accesses) was extraneous, based on statistics gathered from real programs. Early MIPS/Alpha/etc. machines did not support byte addressing, but the people using them still called 8 bits a byte.
- justincormack 7y ago
  Arguably the first Alphas could have had a C compiler with 64 bit bytes but that would have made porting hard. Even then they were forced to add byte operations pretty early on.