With all the sudden interest surrounding Unix, in both its Open
Source form and in the body of OS X, there couldn't be a better
time to install a version of Unix on your Mac.
Open Source
Before you do, though, there is one or two thing you should
consider:
As a Mac user, you're no doubt aware that you are one of a minority.
Though this is often of little consequence in the mainstream computing
world, the Mac's limited user-base does raise some issues in the world
of free Unix. Any free Unix you are likely to encounter is so for one
reason - it is what's known as an "Open Source" operating system.
An Open Source program is one which is entirely in the public domain
- all the programming code (in which it is written before being
compiled into machine language) is out in the open for anyone to see,
use, or modify. Operating systems written under this principle are
crafted by the combined efforts of a legion of volunteers, almost all
of whom are drawn from the user base of the very system they are
creating. This instantly puts any minority system at a disadvantage,
because the smaller the user-base, the smaller the number of skilled
hands available to continually develop the system (remember also, that
only a tiny portion of any Open Source OS' users actually have a hand
in building it).
Also, it's probably fair to say that much of the Open Source
community is drawn to the PC platform if only because people who write
their own operating systems are likely to be the type who enjoy sifting
through IRQ conflicts, fiddling with motherboard jumpers, and the other
assorted delights of PC ownership. What this all boils down to is that
updates, bug-fixes, documentation, and hardware support for Macintosh
Unix systems can sometimes be less far-ranging and can lag behind their
PC equivalents. This also means that many new bits of functionality for
a given Unix clone will appear of the PC first, leaving the Mac
community to wait their turn - occasionally in vain.
The disparity is often less noticeable than you might initially be
led to believe, however, and the Mac teams tend to work on different
priorities anyway. Still, this is an issue you should keep in the back
of your mind, particularly if you like to constantly remain at the
bleeding edge of new technology.
Hardware Support
The sometimes-prolonged development lives of the various Mac Unix
variants usually hits hardest when you first set up your machine as you
run into the issue of hardware support. PC users often come out
smiling: Almost any PC with an 80386 processor or better (i.e., any one
made in the last decade or so) will be able to run a variant of pretty
much any free Unix you can think of - FreeBSD, Linux, or OpenServer.
They may run only a slow, minimalist version, but they will generally
run.
Macintosh support for Unix is patchy in comparison. For example,
OpenBSD will run on both 68k and "New World" Power Macs (those with a
G3 or G4 processor), but those with, say, a Power Mac 7200 are out of luck.
NuBus (x100 series) Power Macs can only run the "MkLinux" distribution.
Macs such as the LC 475 that are
built around the 68LC040 processor won't run any Unix version at all,
due to a glitch in that processor's design, though you can usually get
good results by swapping in a full 68040 processor.
Another obstacle in providing proper hardware support for Unix is
Apple's historical unwillingness to release detailed information about
its hardware. This means that even basic components of your Mac - such
as the floppy drive and sound circuitry - may not work. Of course, if
you're planning to turn your old IIcx into a router or whatever, whether
or not you have sound support may be irrelevant, though it may still
prove a nasty surprise to the unwary.
Generally, the newer your Mac, the less you suffer from this type of
problem, but if you're looking at getting your hands around an old Mac
for some Unix experimentation, be prepared to chose carefully. Also
take care in selecting what hardware you use with your Mac. You'll find
yourself having to pay attention when shopping for such items as
network and video cards, as only some are supported. This is true of
any platform, including the PC, but it can be felt more acutely by the
Mac user given the already comparably limited pool of Mac hardware to
begin with.
Unix Software
Much of the computing world's new found enthusiasm for Unix has been
fueled by the steady stream of productivity applications that have now
been released for the platform. Software such as Corel WordPerfect,
Sun's Star Office, and Applixware have all helped elevate Unix to the
level of a true competitor in the desktop market.
However, the fact that these programs run within Unix does not
necessarily mean that they will run under Unix on a Macintosh - some
developers chose to exclusively target the larger, more profitable band
of PC users.
It's at this point that the distinction between open source and
closed source software comes into focus. Closed source software is the
type we're all familiar with - all the development work is handled by a
company or person who then markets or distributes the software as a
finished whole. You won't find any source code knocking about.
The main problem for users of minority Unix platforms such as the
Mac is that what you see is what you get. If the developers choose not
to support the Mac, then there is nothing you can do about it. In Open
Source software, however, the source code itself is released (sometimes
with a precompiled copy for simplicity). In this case, the user
community is free to modify it to their own ends, which gives Mac users
the freedom to set to work making it run on their computer of
choice.
While few users have the time or skills to pick through and modify
thousands of lines of C programming code, those who do often band
together and make their Mac-friendly versions of Open Source software
available to the public for free. Indeed, many good Unix distributions
will have some Mac-compatible Open Source software thrown in.
What this boils down to is that while there is much good software
available for a Mac running Unix, you might find some of your choices a
bit more restricted than if you were running a majority system like the
PC - a situation which mirrors that of the original Mac OS/Windows
debate.
Another legacy of Apple's preference for closed, proprietary
standards is the fact that the Macintosh was designed from day one to
run the Mac OS exclusively, so when it comes to introducing a new
operating system to the machine, things may not be as smooth as you'd
expect.
Installation
Anyone used to loading a disk and simply executing a program in
order to install a new operating system may be in for a nasty surprise.
While most Unix systems incorporate such a capability across most
platforms, some Macintosh Unix variants (like Debian Linux 68k) expect
you to copy at least part of the system from the CD to you hard disk
manually, and even if you do get an interactive installation, it may
not be all it could be.
Just booting into your newly installed Unix system can also be
somewhat of a hassle. Whereas PCs and dedicated Unix workstations can
load a Unix system at startup, the Mac generally thinks only in terms
of it's own native OS. This means that booting your Mac with Unix may
involve first having to load the Mac OS and then manually startup the
Unix OS, which then replaces it - a somewhat time consuming
process.
Some Mac Unices, such as NetBSD for PowerPC, can be booted without
having to first load the Mac OS, but these still require you to
manually intervene and instruct the Mac to do so each time you
startup.
Give It a Try
Though it may initially sound like your best option for dipping your
toe into Unix would be to rush out and buy the first PC you see, using
your trusty Mac may still make sense. Remember that the Open Source
nature of these Unix variants means that they are being constantly
refined and improved.
Also remember that the introduction of Mac OS X means that the Mac
Unix community has come out with a vengeance. While some tasks can take
some extra work, once setup and established your Mac is more than
capable of providing you with years of reliable, useful Unix
computing.
Also remember that the very openness and raw power offered by these
Unix systems affords you with a great opportunity to get familiar with
the very basics of what makes your favourite computer platform tick.
