CPU architectures (was Re: Win95 won't reboot after Debian install)
On Wed, Mar 07, 2001 at 11:57:44AM +0100, Erdmut Pfeifer wrote:
|
| This A20-line crap rates as one of the most insane ideas ever put forth
| in the whole history of PCs. Anyone who doesn't know already may want to
| read up a little on what it's about, for example here
|
| http://www.phys.uu.nl/~mjanssen/control.php3?chapter=6
| http://www.phys.uu.nl/~mjanssen/control.php3?chapter=9
| (a google search for the exact phrase "A20 line" will turn up a couple
| of more links)
|
| In short, it was born in a desperate attempt at gaining another 64k
| (k!) of memory addressable beyond the 1M limit of the so-called "real
| mode" of 80x86 processors. It was realised by introducing some weird
| mechanics into the PC hardware that allows to switch that special
| addressing scheme on or off.
| It's one of the prototypical examples of how an ad-hoc solution of no
| real benefit can cause headaches for thousands of people. Even years
| after its invention it seems to haunt innocent users. Unbelievable!
|
Oh, interesting. Some more details in how bad the design of the x86
architecture was/is. In my Into to Assembly class we used M68K
processors. The prof spent 1 day giving an overview of the layout of
the x86, and I was really glad then we weren't using x86 systems! The
only advantage I can think of is Pentiums are current and fast while
m68k is a dead (as in nothing new happending) product line.
Does anyone have any overviews/comparisons of Sparc and Alpha designs?
What about ARM? I don't know much (anything realy) about ARM and
where it came from or who made it. I'm really more of a software guy,
but I find the hardware to be interesting as well.
| -- Bugs come in through open windows. Keep Windows shut! --
Nice.
-D
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