Computer Info – January 12, 2000
This Week’s Program
This week we will discuss McAfee
AntiVirus software and install Netscape 4.7 from a CD.
A Portable CD Player That Also Plays MP3’s
http://www.pineusa.com/mp3-cd.htm
Visit this web page to learn
about a portable CD player that will also plays MP3 files that you burn
onto recordable CDs. You can record up to 100 MP3 songs on a single disc
for hours of uninterrupted listening.
MP3 Player the Size Of a Pen
http://vaiodirect.sel.sony.com/
Sony has introduced an MP3
player the size of a felt-tipped marker. It is called the Music Clip. It
will play MP3 files and has a 64 megabyte built-in flash memory which hold
up to two hours of music. It has a built-in equalizer. It connects to your
computer through a USB port. One AA battery runs the Music Clip for up
to five hours.
Automobiles Will Be Able To Play MP3’s
By March, 2000, the United Kingdom
based company, Empeg, should be shipping its dockable car stereo that can
play MP3’s. Instead of feeding this system CDs, you plug it into your computer’s
USB or serial port to download your music. The four gigabyte (GB) model
(priced around $1099) can hold 70 hours of compressed music. This system
stores it on a 2.5 inch hard drive and uses 8 MB of RAM for playback and
1 MB Flash memory to retain settings.
Installing Netscape 4.7 from the CD
Netscape 4.7 can be ordered
on a CD rather than download it. But this CD does not autostart. To begin
the installation process -----
First, uninstall the existing
version of Netscape. All of your email messages – your address book – your
bookmarks – and your preference settings will remain.
Reboot the computer.
Disable your anti-virus
program and close any open programs that you have been running.
To start the installation
of version 4.7 (be sure that you have your CD in the drive) ----
Double-click on MY COMPUTER
Double-click on your CD Drive
You will now see two folders ---- one labeled UNIX and one labeled WINDOWS
Double-click on the WINDOWS folder
There will be only one file in this directory called Cc32e47.EXE.
Double-click on it and the
installation will begin.
Once you have finished the
installation and rebooted the computer – run Netscape. This CD version
of Netscape 4.7 is a 56-bit encryption version. You will have to visit
Netscape’s web site to upgrade to the 128-bit encryption.
AOL 5.0 – Sending Pictures
We recently had a chance to
use AOL for a short test of sending pictures so that they could be received
by everyone.
First we sent ourselves
a picture by using the INSERT PICTURE button on the AOL email form. You
locate the picture on your hard drive and then it is viewable immediately
in the message that you are writing. But when we returned home and received
the message – it only said [Unable to display image]
Then we sent ourselves the
same picture by using the ATTACHMENT button (located in the lower left
corner of the message screen). Again we were given the ability to locate
it on our hard drive – and then it showed that we had an attachment. When
we returned home and received this message – the attachment was there.
Rockwell (or Conexant) PCI 56K Modem
In our handout for 19991229
(December 29, 1999) we mentioned the Rockwell (Conexnat) PCI 56K modem
and connection problems to the internet.
This week we discovered
that Gateway is shipping some of their computers with this modem. SO WHEN
ORDERING YOUR NEW COMPUTER, REQUEST THAT YOU GET A US ROBOTICS MODEM. As
stated in the handout mentioned above, many people will experience difficulties
getting a connection to their Internet Provider when using this modem.
When using AOL 5.0, you
can choose the Rockwell PCI Modem 56K (Force V.34) rather than the
default that it locates in its search for your modem. This setting forces
your modem to connect at 33.6 or less.
How Inkjet Printers Work
(from Smart Computing –February, 2000)
Inkjet printers generally hold
four colors (CYMK – cyan, magenta, yellow, and black). Therefore the printer
has to determine how to place dots of color to represent the colors in
your file. This is done through a process called halftoning.
Once the halftoning process
is complete, the result is a bit map. Every millimeter of the page is laid
out with data representing each of the four CMYK colors. The bits only
tell the printer whether certain colors should be applied to that spot
or not. That’s a lot of data transmitting to the printer. Just saving a
snapshot of the data that is on your monitor screen takes about one megabyte
(MB) of space. To send multiple pages, would require several megabytes
of data.
Data is typically sent to the
printer one line at a time. By a line, we mean one pass across the page.
It typically takes several passes to print one short sentence of 12-point
text. The printer receives the lines of text by storing them in a buffer
(a temporary storage area of memory). When the buffer fills up, the printer
sends a signal to the computer to temporarily stop it from sending data.
As data is taken from the buffer and interpreted into signals sent to the
print head, space in the buffer opens and the computer resumes sending
data; the process is seamless.
The controller is the component
that interprets the commands and sends the signals to the inkjet nozzles.
These nozzles exist in blocks, with a block of several dozen nozzles for
each of the CMYK colors. The Epson Stylus Pro 5000, for example, uses 64
nozzles for each color.
How the nozzles fire the
ink onto the page depends on which technology they use: thermal
or Piezo-electric. Either way, the process has to be precise, especially
considering that the process involves spraying ink onto a page out of nozzles
that are no wider than a single strand of human hair. The droplets of ink
are typically smaller than 10 picoliters. A picoliter is one trillionth
of a liter, or more than a million times smaller than a drop from an eye-dropper.
Piezo-electric inkjet printers
use Piezo crystals. These crystals change shape when an electrical current
passes through them. As a crystal changes shape, it squeezes ink out of
the nozzle. Piezo-electric inkjet nozzles can change the size of the droplets
they place on the page. Simply vary the voltage, and the Piezo crystal
changes accordingly.
Thermal inkjet printers
use heat to fire ink. A heating element in the print head activates and
quickly warms the ink until it forms a bubble. As the ink continues to
heat, the bubble grows until it begins to push ink out of the end of the
nozzle. As the droplet hits the paper, the nozzle is already refilling
with more ink for the next firing. Thermal inkjet printers can generally
produce only a full or half sized droplet by using two heating elements
instead of one.
Currently, Epson is the
only manufacturer using Piezo-electric technology. All other leading inkjet
manufacturers (Canon, Hewlett-Packard, and Lexmark) use thermal inkjets.
Much of the improvements
in inkjet printers today is better ink varieties. Much time and effort
has gone into developing printer ink. If the ink clogs the print head,
changes color when it’s exposed to heat, or doesn’t dry fast enough, the
printout looks terrible. One characteristic that researchers look for when
developing new inks is thickness. They need an ink that flows well and
doesn’t clog the print nozzles, even when heated.