>>>> "der" == der Mouse <mouse
at rodents.montreal.qc.ca> writes:
> Also, the MC68000 has bit-manipulation
instructions that can
> address individual bits, but it is not considered to have one-bit
> bytes.
der> ...The description
der> of the -10 as I read it implied that there was a single object,
der> defined by the hardware, which encapsulated the word address,
der> bit number, and size, which sounds way too much like a bit
der> address. ...
I believe that's right.
For that matter, the Burroughs 6800 has a somewhat similar mechanism
(characters as a subsidiary datatype with hardware-defined character
pointers).
In both cases, you have a construct that consists of a word address
and a byte-in-word address. So the part that describes the byte
describes it as a piece of a given word, which is addressed by another
part of the composite pointer. That's why those are still considered
word addressed machines (36 and 48, respectively) -- the ability to
pick a character out of the word is viewed as a secondary operation
distinct from the primary memory addressing.
paul