Newsgroups: comp.arch
Path: utzoo!henry
From: henry@utzoo.uucp (Henry Spencer)
Subject: Re: Tradeoffs
Message-ID: <1990Jun3.041822.13548@utzoo.uucp>
Organization: U of Toronto Zoology
References: <640@sibyl.eleceng.ua.OZ> <2662CE6C.3E68@tct.uucp> <26798@eerie.acsu.Buffalo.EDU> <266576A7.6D17@tct.uucp> <9494@pt.cs.cmu.edu>
Date: Sun, 3 Jun 90 04:18:22 GMT

In article <9494@pt.cs.cmu.edu> lindsay@MATHOM.GANDALF.CS.CMU.EDU (Donald Lindsay) writes:
>Many years ago, Motorola brought out an 8-bit micro which only needed
>+5V power.  Intel could have done the same, but they decided to beat
>Motorola to market.  And that is why the 8080 needed multiple power
>supply voltages - a pain to designers - and also a big part of why
>the 8080 was the more successful product.  Time to market seems to
>have been the right tradeoff, at that time and place.

Nobody is arguing that heroic efforts to keep software small are justified,
barring rare special situations.  The unhappiness is with people who assign
smallness a value of zero, and refuse to spend five minutes thinking about
how to avoid gratuitous space waste in a many-hour project.

To take a concrete example, C News runs almost as well on a 16-bit-address
machine as it does on bigger ones.  Not because we made heroic efforts to
minimize space, but simply because we cared, somewhat, about memory use.
There are three places where actual effort was required, and where we
might not have made the effort had we not cared specifically about
portability to 16-bit systems.  Elsewhere, it was basically just a matter
of *thinking* for a minute on encountering the temptation to throw memory
at a problem.  The effect on development effort and maintenance effort
is negligible.  Nor has this affected performance:  C News runs circa 20
times as fast as B News, despite using dynamic allocation for virtually
all data structures (thus removing numerous annoying fixed size limits
found in B News).
-- 
As a user I'll take speed over|     Henry Spencer at U of Toronto Zoology
features any day. -A.Tanenbaum| uunet!attcan!utzoo!henry henry@zoo.toronto.edu