On Monday, October 21, 2002, at 06:14 PM, Donald Keenan wrote: > PS Speaking of OSes, I'm reading a "History of Unix for Dummies" kind > of > article for my web development class. It suggests that Unix held or has > the promise of running on any kind of computer. What is being done to > OS > X to make its Unix code machine specific?
Well, that was an oversimplification. Unix (or some unix-ish variant) pretty much *does* run on any kind of computer (capable of running it, that is.) While GNU's Not Unix in it's famous recursion, a better definition s GNU's not a proprietary Unix. For all intents and purposes Linux, BSD (which is the basis for Darwin, and stands for Berkeley Standard Distribution, one of the earliest available Unix variants), Darwin, Xenix, etc etc are, in fact all some form or another of the OS called Unix. In the Beginning, Kernigan and Ritchie envisioned a universal operating system, and LO it was good. They worked in an era where pretty much every single brand of computer (or model, in fact) was radically different. They aimed for a Single OS to work on all of them. It was ported to all manner of hardware, but it was a simple OS, with few bells and whistles, but it worked. A program could be run on a new machine simply by recompiling it. Then <insert ominous thunder FX> AT&T DID allow Berkeley to tinker with the Source Code and thus the first Great Schism was born: BSD vs SystemV. Unix started to diverge from itself. You had SystemV programs or BSD programs, SystemV commands which were identically named, yet confusingly different from BSD commands (both had the command 'ps' each had *different* parameters.) Fast forward through a lot of Old-testamentish begatting and burning of kith and kine, and you end up with todays situation, where every supplier of Unix in history has modified it slightly and tweaked it here and there, (or done horrible Frankensteinian experiments on it like HP's HP/UX which was a weird cobbled together thing made from bits of HP's dead System V version, and Apollo's graverobbed BSD version. Shudder. I HATE HP/UX!). Along the line, the original vision of a simple OS portable to all manner of systems, yet running the same on each has gone pretty much by the wayside. The main strains today are not BSD vs System V, but Linux vs BSD (also vs Linux vs Linux vs Linux...etc). We used to have a sign above our server 'rack' (back then, just a table with 5 or 6 machines on it) that said 'You are in a maze of twisty little Unices, all slightly different' ;-) For simple programs; command-line things that don't make reference to a huge number of different libraries, or include all of their C-code themselves, and don't use *any* libs, the promise of 'Run everywhere' does hold true, still. It's just that things like GUI interfaces, high-level API's and such simply don't hold to the standard 'recompile and run everywhere' philosophy that guided the origins of Unix. (K&R simply wanted to retain a stable development environment amongst all the hand-me-down systems that they were scrounging.) They are complex pieces of programming, and absent a universally accepted standard, don't interoperate all that well. Java comes closer to that ideal than Unix now, but even it isn't perfect. > -- Wherever you go, there you are. Bruce Johnson -- G-Books is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Check our web site for refurbished PowerBooks | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> G-Books list info: <http://lowendmac.com/lists/g-books.html> --> AOL users, remove "mailto:"; Send list messages to: <mailto:G-Books@;mail.maclaunch.com> To unsubscribe, email: <mailto:G-Books-off@;mail.maclaunch.com> For digest mode, email: <mailto:G-Books-digest@;mail.maclaunch.com> Subscription questions: <mailto:listmom@;lemlists.com> Archive: <http://www.mail-archive.com/g-books%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
