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Date:      Tue, 19 May 1998 23:57:14 +0200 (MET DST)
From:      Wilko Bulte <wilko@yedi.iaf.nl>
To:        freebsd-hackers@FreeBSD.ORG
Cc:        freebsd-hackers@FreeBSD.ORG
Subject:   Re: talk (fwd)
Message-ID:  <199805192157.XAA04150@yedi.iaf.nl>
In-Reply-To: <199805191808.UAA17299@dorifer.heim3.tu-clausthal.de> from Oliver Fromme at "May 19, 98 08:08:49 pm"

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As Oliver Fromme wrote...
> In list.freebsd-hackers Mike wrote:
>  > [...]
>  > I've always heard (I have no motorola experience, yet) that motorola asm
>  > blows x86 away when it comes to efficiency.  A friend I have develops for
>  > Be and he's always ranting about it. :)
> 
> He's right.  The x86 has 4 general-purpose registers, each of
> them 16 bits (they were extended to 32 bits in the 80386) and
> 4 address registers of the same size.  And there are certain
> restrictions on their usage, e.g. you can only use the CX
> register as counter in the "loop" instruction etc.
> 
> On the other hand, the Motorola 68k has 8 general-purpose
> registers of 32 bits and 8 address registers (also 32 bits).
> There is no restriction on their use, except that the 8th
> address regsiter is the default stack pointer.
> 
> I programmed on both architectures in assembler, and I have to
> say that the 68k is definitely easier to program, and the
> higher number of registers allows for efficient programming.
> 
> Maybe it was the biggest mistake ever made in computer history
> when IBM selected the 8088 for their first PC back in 1979.
> (Or was it 1978?  Don't know, I probably couldn't even spell
> the word "Computer" correctly back then.)  If they used the
> 68000 -- which was already available at that time -- we would
> have less problems today, I guess.

An attractive (to me ;-) explanation is that IBM did not want to use the
68K because it was a threat (performance wise) to their high profit machine
range.

Urban legend or not, it sure sounds OK ;-)

_     ______________________________________________________________________
 |   / o / /  _  Bulte 				  email: wilko @ yedi.iaf.nl 
 |/|/ / / /( (_) Arnhem, The Netherlands          WWW:   http://www.tcja.nl
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