Re: Interview with Alan Kay

From: Tim May (timcmay_at_removethis.got.net)
Date: 02/22/05 

Date: Tue, 22 Feb 2005 10:46:16 -0800

In article <WNOdnWDErJNdpobfRVn-sQ@wideopenwest.com>, Thomas Gagne
<tgagne@wide-open-west.com> wrote:

...quotes from Alan Kay's interesting interview...

> so forth. Time-sharing was held back for years because it was "inefficient"--
> but the manufacturers wouldn't put MMUs on the machines, universities had to
> do it themselves! Recursion late-binds parameters to procedures, but it took
> years to get even rudimentary stack mechanisms into CPUs. Most machines still
> have no support for dynamic allocation and garbage collection and so forth.
> In
> short, most hardware designs today are just re-optimizations of moribund
> architectures."

What Alan Kay says is no doubt true, but the real issue has always been
that computer architecture, especially for workstations and PCs, has
been a popularity contest: one architecture wins out.

There are multiple reasons for this, including "most popular gets more
users, hence more software," and "learning curve" (costs of production
lower for higher-volume chips), and, I think most importantly, "limited
desktop space means one machine per desktop."

In the 80s and into the 90s, this meant a Sun workstation or equivalent
RISC/Unix/C machine for engineers and designers, an IBM PC or
equivalent for most office workers, a Macintosh for most graphics
designers or desktop publishers.

It didn't matter if a Forth engine was great for Forth, or a Symbolics
3600 was great for Lisp, or a D-machine was great for Smalltalk: there
just weren't many of these sold.

Similar things happened in minicomputer and mainframe computer markets.

I was at Intel from 1974 to 1986 and saw efforts to introduce new
architectures (432, 960, 860, iWarp, other processors from other
companies, such as Z8000, 32032, Swordfish, etc.). Mostly these efforts
failed. (There are various reasons, but most never got a chance to be
tweaked or fixed, because the "market had spoken.") The customers
wanted x86, despite obvious shortcomings. Niche architectures mostly
died out. And such is the case today, even more so than back then.

(Something that may change this is the "slowing down" of Moore's
observation about doubling rates. For good physics reasons, clock
speeds are not doubling at the rates seen in the past. This may push
architectures in different directions.)

So while there are all sorts of things that _could_ be put into
computer architectures, limited desktop space and the economies of
scale pretty much dictate a slower rate of adding these features.

--Tim May

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