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Yes, Java is indeed different from JavaScript.
java is also an operating system in its own right. However, there are
only a few dozen Java PCs in the world at this time. Most of those are at
Sun Microsystems. Those machines run Java directly. Being fairly small
compared with Windows, the whole OS is stored on ROM. Whenever the machine
is turned on, there is no waiting time for the OS to load.
Most of us don't have a Java machine, so we have to install a
"Virtual Machine" first. This virtual machine - or JVM - communicates
between Java and the operating system of the physical machine. JVMs are
available for practically any platform, hence the portability.
Using a virtual machine introduces some problems, though: As really
two operating systems are used, with the VM to translate between the two,
a noticeable drop in performance can be experienced.
Technically speaking, there is really no JVM for Windows. It is
really a DOS application. That's true for the Sun JVM. I have a feeling
the Microsoft version may not work under DOS only systems. When installing
the Sun Microsystems Java Virtual Machine, the following should be added
to the autoexec.bat file:
set
classpath=c:\java\lib\classes.zip;
path=c:\java\bin
Java does NOT need Windows to run. The Sun Microsystem's JVM for DOS
is a DOS-based application. Even some Windows versions work in a DOS-only
environment. Having said that, I have to admit that later versions (higher
than 1.1) may not work correctly on DOS-only systems. Especially later
versions may be taylored to run on the newer, non-DOS based Windows (NT,
2000 and XP). So, if you download a version, try to get an old one:-) The
DOS version 1.1 works fine here under DOS 6.22. All Java needs is DOS and
the correct Java JRE.
Almost all Java programming is done in DOS text mode (even if Windows
is the OS), and the code is compiled from the command prompt. The code is
similar, but not the same, as C++ code, so C programmers will find it
easier to learn. There are really no practical GUI interfaces for
programming in Java. Everything, even graphics, have to be coded in a text
editor of some kind before compiling. Borland JBuilder (Windows needed)
makes things easier, but is still only a better text editor. For easier
graphical interfaces, Osborne and Lambert's "BreezyGUI" (no Windows
needed) can be very helpful for beginners.
Even though Java is said to be the fastest growing language (probably
because of web applets), I can think of only two truly practical
application, which is "Corel Office for Java", which includes
WordPerfect, QuattroPro and a schduler. (Details: http://developer.novell.com/research/devnotes/1997/may/16/),
and Lotus Kona, which includes everything MS Office does. I was able
to download a copy of Corel Office for Java a couple of years ago, but the
site seems to have gone. If anyone is interested, let me know.
Sun Microsystems also developed a pure Java web browser called
"HotJava", which runs on any java platform below 1.2. Again, if the proper
JVM is installed, Windows is not necessary to run this browser. It can
handle Java (of course!) and JavaScript as well. The browser can be
downloaded from http://java.sun.com/products/hotjava/3.0/
I use the Java for DOS JRE 1.1 on an old 486DX66, 1MB RAM, 30MB
HDD. This allows me to connect the machine to the network and thus access
the Internet, using the fully graphical HotJava browser.
Another option could be to install RJ-DOS (if you can find it), which
is a DOS platform which includes a JVM.
Hope this helps.
Dr. Ron
-------Original Message-------
Date: Sunday, 29
December 2002 05:55:55 AM
Subject: Re: now, DOS
is JAVA
We had a discussion on the List, some time ago, and if I
recall
correctly JAVA is totaly different to
java-script.
Java-script is bad... not handled by
Arachne
Yes, it was mentioned that JAVA is running in every
operating system...
is it an operating system itself?
Who knows
some more about JAVA?
CU, Bastiaan
On Fri, 27 Dec 2002
21:01:30 +0000, Ariel Lachter wrote:
> (sorry my bad
english)
> Yesterday "the bad" are frames.
> Now "the bad" is
java.
> I see in freebyte that make programs that run in any
>
operating system with virtual java machine.
> Maybe is time to
change, d.o.s ==> java.
> Who take the bull by the
horn's?
> -- Arachne V1.70;rev.3, NON-COMMERCIAL copy, http://arachne.cz/
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