Path: utzoo!attcan!uunet!ncrlnk!ncrcae!hubcap!gatech!cwjcc!tut.cis.ohio-state.edu!osu-cis!att!ihlpl!knudsen
From: knudsen@ihlpl.ATT.COM (Knudsen)
Newsgroups: comp.lang.c
Subject: Re: Assembly or ....ok
Summary: Flight Sim ported anyway
Message-ID: <8215@ihlpl.ATT.COM>
Date: 16 Dec 88 16:28:55 GMT
References: <11915@cup.portal.com> <207600012@s.cs.uiuc.edu>
Organization: AT&T Bell Laboratories - Naperville, Illinois
Lines: 32

In article <207600012@s.cs.uiuc.edu>, carroll@s.cs.uiuc.edu writes:
> Fascinating. I worked at SubLogic for a summer, and they write *everything*
> in assembler. One of their products is FlightSimulator (what MicroSoft puts
> their name on and sells as if they wrote it). The object code for it is
> far more than 1K long, and no compiler every matched it for speed or
> compactness. In fact, one of the reasons for the success of the company is
> that the speed critical routines (such as the 3D-2D perspective transforms)
> worked so fast. There is *no* way they could have been done in a high-level
> language - the abuse of the machine features is amazing. I personally have

I'd agree with everything the author says.
What is really extraordinary
is that SubLogic's FS and FS-II have been
ported to so many other machines besides the PClones.

You can get it for the Color Computer (6809) and some of the 68000
machines, and maybe the Commo-64 and Apple-II (6502).
All these micros have features to "abuse" (love that term),
but they're all different.

A big argument in favor of C is the ease of porting, but SubLogic
seems to have ported pretty well even in assembler.
I guess the projected sales of FS allowed them to throw enough
bodies at the job to get it done.
Of course if the origianl 8086 assembly source was well laid out
and documented, porting to another assembler is a lot easier than
writing from scratch.  But you have to discard the old
"abuses" and come up with new ones.
-- 
Mike Knudsen  Bell Labs(AT&T)   att!ihlpl!knudsen
"Lawyers are like nuclear bombs and PClones.  Nobody likes them,
but the other guy's got one, so I better get one too."