From: rjc@hal.gnu.ai.mit.edu (Ray)
Newsgroups: comp.sys.amiga.advocacy
Subject: Re: 040 and 486 and nap42487 knows nothing about CPUs.
Date: 13 Apr 92 16:56:35 GMT
Article-I.D.: mintaka.1992Apr13.165635.21886
Organization: /etc/organization

In article <1992Apr13.152041.13375@ctr.columbia.edu> jerry@connection.prospect.com (Jerry Shekhel) writes:
>rjc@hal.gnu.ai.mit.edu (Ray) writes:
>>
>>  Let's just face the fact (my personal opinion) that the Intel
>>instruction set sucks, its kludgy, modal, limited in registers, not
>>orthogonal. Its a real bitch to program in assembly compared to Motorola.
>>
>
>I disagree.  Why don't you stop throwing around the word "kludge", since
>you obviously don't know what it means.  Geez, according to Amigoids,
>everything non-Motorola and non-Amiga is a "kludge".  As far as the
>instruction set goes, I maintain that it's different, not worse.  Ortho-
>gonality isn't everything.

   The Intel HW is kludgy because it lacks the elegance of the Motorola
chips. For instance, 16-bit mode vs 32-bit mode. There is only one
reason the 16bit mode is still there, backwards compatibility. The Intel
hardware is carrying around extra baggage from it's 16bit days because
it cannot afford to drop ms-dos compatilibility. Motorola 680x0 started
out with full 32bit registers (24bit addressing), and a flat memory model.

  Jerry, why don't you tell me what makes the Intel instruction set/design
better than Motorola's?  Is it all the overloading of registers (special
case side effects)? The different modes? The segments? The small amount
of general registers? The convoluted mnemonics?

   There are only two possibilities I see, the string copying instructions,
stuff like 'rep' etc, and the 32bit segments.

   Other than that, none sane assembly programmer would touch it. I've been
an assembly programmer for 6 years, and I associate with people who
program both CPU's (and a hell of a lot more, like 6502s, 68HC11, etc)
The concensus is (even by intel asm programmers themselves) that the
Motorola instruction set is better.

  I converted an Intel friend of mine a few months ago just by giving
him some of my 68k source and explaining the 68k to him. He thought that
Motorola was so much better. (the application was one of clocking
in bits off the parallel port and timing them to 100us or less. We also
learned how shitty the IBM timer chips are compared the MOS(Commodore)
CIA chips. The CIA's are a hundred times more flexibile. One-shot,
continuous, transition on external pin, transition on O2, etc The CIA's
are the port chips in the C64 and the Amiga. They have 3 timers, 2 ports,
bidirectional, and lots of ways to interact with outside signals.)


  Do you deny Jerry that the IntelHW carries extra baggage that's not
really needed for a real-32bit OS? The V8086 mode smacks of chip
level multitasking kludge added for ms-dos virtual machines!

  It doesn't matter how you answer, since I will be vindicated anyway.
Intel is eventually going to drop the 16bit mode and compatibility
instructions, or so they say.
    
>--
>+-------------------+-----------------------+--------------------------------+
>| Jerry J. Shekhel  | Molecular Simulations | Time just fades the pages      |
>| Drummers do it... | Inc.  Waltham, MA USA | in my book of memories.        |
>|    ... In rhythm! |     (617) 890-2888    |              -- Guns N' Roses  |
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>|           ...! [ princeton mit-eddie bu sunne ] !polygen!jerry             |
>|                            jerry@polygen.com                               |
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