Re: binary i/o files
- From: Glen Herrmannsfeldt <gah@xxxxxxxxxxxxxxxx>
- Date: Wed, 18 Feb 2009 17:01:21 -0700
Ron Shepard wrote:
I just checked wikipedia, and ascii still has only 128 characters in it.
I've been expecting it to be extended up to 256 for some time now, but it hasn't happened yet.
When IBM was designing System/360 there was a proposal for an ASCII-8
that was not just an extension with the ASCII-7 characters as the
first 128. With bits numbered from 0 (lsb) to 7 (msb) ASCII-8
would have been formed by duplicating bit 5 as bit 7 for the
ASCII-7 characters. There were some features of the S/360 instructions
designed around that, but were removed in designing S/370.
(The bit to enable them required supervisor mode, and no OS were
known to activate that bit.)
That makes it about 45 years, and still hasn't happened.