Odd "endianness" [was Re: RE: Base 64 posts to the list]

Chuck Guzis cclist at sydex.com
Sat Dec 17 15:59:03 CST 2016


Here's a tickler for the list...

I've used bit-addressable machines, where individual bits were directly
addressed without regard to their position within a byte or word.  E.g.,
a system with 48 bit addresses, where the lower 3 bits of an address
specified the bit within a byte; the next 3 specified the address of a
byte within a (64 bit) word, and so on.  Bit vectors were an important
part of the architecture.

What perplexed me is that the address of 0000 0 0 specified the first
bit in byte 0 of word 0, but that same bit was the *high order* bit in
the corresponding byte and word.  It would seem to make more sense
reversing the significance of bits in a byte and bytes in a word such
that the lowest-numbered addresses corresponded to the least-significant
bits in a word or byte.

Call it "extreme little endianess".  Does anyone know of such an
architecture?

--Chuck



More information about the cctalk mailing list