Re: How many times must Apple make such DRASTIC architecture changes?

[Paul Schlyter <pausch.NO@SPAM.saaf.se>]

In article <wcf*CoOQq@news.chiark.greenend.org.uk>, 
timc@chiark.greenend.org.uk says...
>In article <3gr18rFcobl4U1@individual.net>,
>Ilgaz Ocal  <Ilgaz@spamcop.net> wrote:
>>We all miss something, this type of transition from one CPU family to 
>>other has NEVER happened in IT history.
>
>Rubbish.  It's happened to VMS twice.  VMS started out on the VAX
>architecture, moved to Alpha, and finally it has moved to Intel
>Itanium2.  Who knows, it may have to move again if Itanium2 fails.

It even happened to the Mac earlier, when it writched from 68K
to PowerPC .....

>It's happened to Sun machines to.  Very early Sun workstations were
>based on the i386 processor, and only later moved to SPARC, and then
>again to UltraSPARC.
>
>It's happened to Silicon Graphics machines; some of the varieties of
>MIPS processor are *very* different from each other.
>
>It's happened to DEC UNIX machines.  They started out with some on i386
>and some on MIPS, and then moved to Alpha.
>
>In almost every part of the computing world *except* the PC world, major
>architecture changes are quite common.  They're usually pretty painless
>in the UNIX world, because UNIX apps don't talk to the hardware
>directly, and so a simple recompile is all that's required.  I run Linux
>daily on six different architectures - Alpha, two very different
>flavours of Itanium2 (SGI Altix and HP rx4640), x86, x86_64 and PowerPC.
>And all my software just compiles and runs without modification on any
>of them.

Otoh you'll have to get updated device drivers whenever there's a major
change in architecture.  This is manageable in the UNIX world, where 
relatively few hardware devices are connected.  But the PC world is 
different - nowadays there are so many different hardware devices you can 
buy cheaply and attach (most often to the USB port).  And e.g. every brand 
of digital camera seem to require its own device driver.  A major 
architecture change may then mean not being able to use perhaps half of 
these devices after the change, because the manufacturer didn't supply an 
updated driver.

>Don't get hung up on processor and architecture changes; if the OS and
>software are written right, and I think that's the case (at last) with
>OS X, then it really doesn't matter at all.
>
>Tim
>
>

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Paul Schlyter,  Grev Turegatan 40,  SE-114 38 Stockholm,  SWEDEN
e-mail:  pausch at saaf dot se
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