Droid issues - Legacy Bash IFS var clobbering VLIW offset?

Walter Dnes waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org
Fri Nov 25 21:24:35 UTC 2011


On Fri, Nov 25, 2011 at 10:28:59AM -0500, Lennart Sorensen wrote
> On Fri, Nov 25, 2011 at 08:30:58AM -0500, Russell Reiter wrote:
> > The man who founded MS said who needs more than 640k or did he?
> > 
> > http://www.computerworld.com/s/article/9101699/The_640K_quote_won_t_go_away_but_did_Gates_really_say_it_
> 
> Ah the old 640k issue.  Yet another stupidity of the x86 design by intel.

  What Intel *REALLY* did wrong...

* The original 8080 was a 16-bit processor that addressed 65,536 bytes

* The 8086 (and the similar 8088) was the next version.  To increase the
  adressable space, they used a 16-bit base register and a 16-bit offset
  register.  The real stupidity was that the address was calculated as...

  (16 * base_register) + offset register

  See http://en.wikipedia.org/wiki/Intel_8086#Segmentation  This meant
  that 2 16-bit registers combined to only 20 bits of address space
  (i.e. 1 megabyte) in real mode DOS.  Throwing away 12 bits meant that
  there were 4096 ways to express the same address.  It's a crying shame
  that Intel didn't use a base+offset scheme that went something like...

  (4096 * base_register) + offset register

  That would've given 28 bits of address space, (i.e. 256 megabytes) in
  real mode DOS.  The history of DOS would've been totally different,
  without EMS and HIMEM garbage.

-- 
Walter Dnes <waltdnes-SLHPyeZ9y/tg9hUCZPvPmw at public.gmane.org>
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