Byte sizes (was Re: 2.8M 3.5' floppy (was: three and a quarter loppy?)
eric at brouhaha.com
Mon Mar 14 13:52:06 CST 2005
der Mouse replied to my description of PDP-10 byte addressing (0-36 bits)
and someone else's claim that a byte is the smallest addressable unit
> That sounds a whole lot like a hardware-supported way of addressing an
> object of an arbitrary size in bits. And that would mean that bytes of
> any size *are* individually addressible.
Any size from 0 to 36 bits.
The problem with the "smallest addressable unit" definitition is that
it would mean that the byte size of a PDP-10 is *only* zero bits, because
that's the smallest. (Or one bit, if you can define it in a way to rule
out the zero bits case.)
Also, the MC68000 has bit-manipulation instructions that can address
individual bits, but it is not considered to have one-bit bytes.
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