UNIX CONVERSIONS
(By David Johnson)
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Welcome to UNIX CONVERSION, hopefully a regular here at
MODEMNEWS. I would like to start with an offer to allow you the
reader to mold this column to your desires. I will be writing about
UNIX in general as well as how it is similar or different to DOS. I
even plan to cover some subjects on converting from DOS to UNIX
since it has become so popular these days.
First let me explain a little about myself. I am the SYSOP of
"The Unknown RBBS" operated on Long Island NY. I started my system
4 years ago to help beginners get started on computers as well as
answer questions about AT&T computer products. After a very short
time my system grew rapidly to what it is now. The Unknown operates
on a dedicated AT&T 386 machine with two nodes running under Desq-
view with 318 Megs of disk storage.
WHAT IS UNIX?
Let me just start todays column with a quick description of UNIX
and compare it to DOS. UNIX is an Operating system just like DOS in
that it is the master control program that give the machine its
personality after booting up. DOS (both MS and PC) have a control
program called COMMAND.COM which is about 12K to 16K in size
depending on the version and brand. This program is used to
initialize the machine and give you the A> or C> prompt you are all
so familiar with. It is also just one of several DOS related
commands that fit on the two 360K formatted disks when you purchase
DOS. So it is safe to say that all of DOS and its support programs
(about 30 commands in all) could fit in about 720K of disk space.
Lets get an idea now of the size of UNIX.
The master control program of UNIX is called the KERNEL. This
program is executed when a UNIX machine is booted and eventually
give a user a $ prompt which is equivalent to the DOS A> or C>
prompt. The UNIX kernel can be as small as 380K or on a standard
386 machine 1.4Meg big, or on other larger UNIX machines over 2 Meg
in size! ALL of UNIX and its support programs (about 300 - 500
commands) comes on anywhere from 10 to 45 1.2 Meg disks! On some of
the larger machines it is sold only on 60 Meg tapes because its so
large. But don't let this scare you because in most cases it is
much smaller for use on 386 based machines.
As you can see it is not possible to run UNIX on a floppy only
based machine. In fact, AT&T had a lot of problems selling UNIX
machines with 10 Meg hard disks since there was less then 1 Meg
left for user programs. A typical UNIX system for the end user
these days is sold with a 40 or 68 Meg hard drive. One of the major
advantages of UNIX is that it is user configurable. This process
similar to a DOS CONFIG.SYS file consists of dozens of files that
can be changed to allow dozens of SERIAL and PARALLEL ports,
multiple users (simultaneously) and even allows you to run several
programs at once, both DOS and UNIX! Sound too good to be true, no
its not, but there is a price you pay for this and that will be the
topic of discussion for the next issue.
Well I can see I'm out of space already, so I will just end this
by saying that you can help decide what gets written here by
leaving your suggestions on "The Unknown RBBS" at 516-486-4813.