[rescue] From Macintouch

[Geoffrey S. Mendelson]

On Tue, Jun 07, 2005 at 12:54:38AM -0400, Patrick Giagnocavo wrote:

> Thing is, if there is little performance degradation, then Apple's
> claims of the CPUs being faster than Intel's looks like a lie.

That's an interesting point. There are several ways to speed up emulation,
I assume Apple will use them all. For example:

1. Recognize system calls and execute them in native code. Since the operating
   system will be the same this is relatively easy. It's a lot easier than
   translating MS/Windows system calls to X windows and Linux system calls
   as in wine.

   Many applications are mostly system calls with a little code wrapped
   around them. They will execute with "near normal performance".

2. Block translate code to the X86 instructions. Keep the translated
   code in a buffer for later use, and possibly save it in a file.
   This was pioneered in Basilisk II, a 68000 Macintosh emulator
   which runs on Linux among other things. 

   On a PI 166, it was fast enough to run real time games. My wife still
   plays her favorite pinbal game, Crystal Caliburn that she bought for
   a Mac circa 1991 using BII on a 1500mHz AMD machine now.

3. Recognize blocks of code and replace them with native code. Since the
   code being emulated is 99.99%  compiler generated, this would not be
   that difficult.
 
As for developers, I'm sure they all love the idea. It will force all
of those people who haven't upgraded in a while to buy X86 binary
upgrades. 

I'm not sure that the perception that PPC macintoshes are faster at
lower clock speeds than X86 processors exists in the general public.
Most people I know who are not geeks, don't understand that or
they would have bought AMD processors long ago.

I think the success of the iPod drove many windows users to consider the
Macintosh, which is why Apple produced the Mac mini. I'm also sure they
had lots of complaints from dealers who had trouble selling 1.2gHz Mac
mini's to people looking at 3gHz P4s.

> I think that Apple will have seriously reduced hardware sales for the
> next year.  The iPod and iTunes will have to hold their bottom line up
> for them until the first x86 boxes ship.

I don't know, lots of people are going to take advantage of the lower
prices to upgrade now while they can. I expect that there will be a lot
more Mac mini's sold and eventualy when the G5's go down in price,
they will sell out quickly. 

I expect that's really Jobs' strategy, sell out the PPC stuff at low
margins and make it up in volume and then sell X86 machines to 
the people who just bought PPC machines.

Geoff.

-- 
Geoffrey S. Mendelson, Jerusalem, Israel gsm at mendelson.com  N3OWJ/4X1GM
IL Voice: (077)-424-1667  IL Fax: 972-2-648-1443 U.S. Voice: 1-215-821-1838 
VoN  Skype: mendelsonfamily. Looking for work as a CTO or consultant in 
handheld gaming, large systems development, handheld device construction, etc.
See U.S. patent applications  20050108591,  20050107165.