[TUHS] v7 K&R C
Peter Jeremy
peter at rulingia.com
Mon May 18 18:46:50 AEST 2020
On 2020-May-17 16:08:26 -0400, Clem Cole <clemc at ccc.com> wrote:
>On Sun, May 17, 2020 at 12:38 PM Paul Winalski <paul.winalski at gmail.com>
>wrote:
>
>> Well, the function in question is called getchar(). And although
>> these days "byte" is synonymous with "8 bits", historically it meant
>> "the number of bits needed to store a single character".
8-bit bytes, 32/64-bit "words" and 2's complement arithmetic have been
"standard" for so long that I suspect there are a significant number of
computing professionals who have never considered that there is any
alternative.
>Yep, I think that is the real crux of the issue. If you grew up with
>systems that used a 5, 6, or even a 7-bit byte; you have an appreciation of
>the difference.
I've used a 36-bit system that supported 6 or 9-bit bytes. IBM Stretch even
supported programmable character sizes.
>DEC was still sort of transitioning from word-oriented hardware (a lesson,
>Paul, you and I lived through being forgotten a few years later with
>Alpha);
The Alpha was byte addressed, it just didn't support byte operations on
memory (at least originally). That's different to word-oriented machines
that only supported word addresses. Supporting byte-wide writes at
arbitrary addresses adds a chunk of complexity to the CPU/cache interface
and most RISC architectures only supported word load/store operations.
--
Peter Jeremy
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 963 bytes
Desc: not available
URL: <http://minnie.tuhs.org/pipermail/tuhs/attachments/20200518/e4bcf4e6/attachment.sig>
More information about the TUHS
mailing list