BVCC Officers Chair: Fred Schneiter Vice Chair.: Bob Cunningham Treasurer: Esther Kordes Secretary: Gerry Salisbury Newsletter Editor: Len Nasman

Transcription

1 Bristol Village Computer Club News BVCC Officers Chair: Fred Schneiter Vice Chair.: Bob Cunningham Treasurer: Esther Kordes Secretary: Gerry Salisbury Newsletter Editor: Len Nasman Under the Hood - Memory Try to remember the kind of September when grass was green and grain was yellow What About Other Kinds Of Memory? Last time we discussed RAM and ROM, and also mentioned flash drives. As you recall, ROM (Read Only Memory) is fairly permanent and is where the instructions for starting the computer are stored. RAM (Random Access Memory) is electronic memory where applications (like word processing) are placed while they are being used. Electronic memory has no moving parts and since it is directly connected to the CPU (Central Processing Unit) is fast. The other general type of memory is (semi) permanent and includes floppy and hard disk drives, flash drives, and CD s. Stuff is stored there in files. Some files contain the application programs like word processing or , and other files contain the data, like words or pictures, that the application programs use. Floppy disks at one time were mostly 5 1/4 inches in diameter in flexible sleeves. They were replaced by the smaller physically, but larger memory capacity 3 inch discs in plastic cases. Hard drives use basically the same material (microscopic magnetic powder) as floppy disks, but the discs have a higher density and have very small read/write heads so they hold a lot more than floppy discs. As a matter of fact, the clearance between the disc and the drive head in a hard drive is so small that a particle of cigarette smoke is big enough to cause it to crash. Floppy disks have a little window that the disk drive uses for the read/write heads to save and retrieve information. However, hard discs and their read/write heads are enclosed in sealed boxes. As disk drive technology has improved, the storage capacity has improved. My first 5 1/4 inch floppy disks could hold 98 K bytes (ninety eight times 1,024 computer words) of information. Early hard disk drives could hold 10 or 20 million bytes. Today, it is not uncommon for a new computer to come with a hard drive that holds 250 or 400 gigabytes. Why is computer memory specified in multiples of 1,024 instead of 1,000? Glad you asked. Computers use binary arithmetic, that is they deal with only 2 numbers, 0 and 1. We humans are smarter. We use 10 numbers. Well, actually nine plus 0. When we get to 9 we start over with 1, but add a zero. When we get to 99 we add another place and another 0. Actually we use powers of = 10, 10 2 = 10x10 = 100, 10 3 = 10x10x10 =1000, etc. This document was prepared using the free Open Office Writer Software

2 Page 2 of 5 Name Value Equals kilobyte = ,024 megabyte = ,0048,576 gigabyte = ,073,741,824 a thousand million terabyte = 24 0 a million million In binary, the computer counts in a similar way, but in powers of 2 instead of = 2, 2 2 = 2x2 = 4, 2 3 = 2x2x2 =8, and, if you keep going, 16, 32, 64, 128, 256, 512, and finally 2 10 = 1,024. How big a hard drive do you need? As the memory technology has improved, the programs and data files require more and more memory. A few years ago, you could store the words to several 100 page essays (in plain text) on a floppy disk. Then programs started enhancing the text with bold, underline, fancy fonts, and other cosmetic features. This increased the amount of memory required. However, the big jump in required memory comes when you start adding pictures and sounds. One picture from an average $200 digital camera can no longer fit on a single floppy disk. Add motion pictures (digital video) and the required memory makes an even bigger jump. If you will be saving any videos in your computer, a 160 gigabyte hard drive is probably not big enough. If you are upgrading or replacing your computer you might as well go for at least a 250 gigabyte hard drive. CD s and DVD s I can remember receiving computer programs that required over a dozen floppy disks to install. As software file size inflated, it became clear that an economical way to deliver large volumes of computer files was needed. The answer was the CD. Instead of the magnetic particles used in floppy and hard disks, CD s store bytes of data with microscopic pits in a shiny surface. When a light (from a laser) is shined on the surface it either is reflected or not depending on the presence of a pit. Here again is an either/or situation that can be interpreted as a 1 or a 0. CD s can be commercially stamped out from a master in one quick stroke, making it possible to reproduce disks with a lot of data for a low cost compared to recording the same amount of data on multiple copies of magnetic disks. For more info about CD s try: cd.htm When CD s were developed, the sound recording industry got together with the computer industry to use the same technology for storing either music or computer data. After all, digital sounds are just More!!!

3 BVCC January, 2008 another piece of digital data. The movie industry followed the same path with DVD s. Play or record? There are two types of CD and DVD disk drives in computers, players and recorders. As prices have come down, most new computers come equipped with disk drives that can either play or record both CD s and DVD s. CD, CD-R, CD-RW, DVD, DVD-R, DVD-RW??? What s the difference between these disks? A CD or DVD can only be played, not recorded on. CD-R and DVD-R disks can be recorded on (also known as burned) one time. CD and DVD RW disks can be recorded on over and over again. So why bother with CD R or DVD-R? The problem is that not all re-writable disks can be played on all players. If you want to store data on a disk that can be played on a different computer (or even a player attached to a TV set), the best bet is the CD-R or DVD-R version. Be sure to look close at the package before you pay for a stack of new disks and be sure you get the kind you need. WARNING! BACK-UP, BACK-UP BACK-UP Whatever memory type you use to store your computer data, you should assume that the storage system will fail some day. We recently had a case in the computer room where a computer was brought in that displayed the dreaded black screen of death. The computer would no longer start. The hard drive was a candidate for the memory loss wing of computer purgatory. The bad news was that the hard drive contained an archive of family picture files that could not be replaced. The first attempt to retrieve the lost files was to remove the hard drive and connect it to a different computer that did not need the information on the old drive to start up. Unfortunately, the hard drive was flawed in a way that the second computer also could not find the data. The solution was to run a program that analyzed the contents of the hard drive bit by bit and tried to work around the bad parts of the disk. After the nearly 4 hours this process took, we were able to recover about 90% of the lost files. But we were lucky in this case. More often than not the data would be lost forever. The moral of this story is to make copies of all of your important data files. Since CD s are fairly dependable, they can be used to back-up files. However, if you have a lot of pictures, they might not fit on a single, or even a small stack of, CD s. My current preference is to get one or more external hard drives. They can be attached to most computers through a USB port. Once attached, the computer sees them as just another disk drive and you can easily copy files to them. A big advantage is that the external drives are very easy to move from one computer to another. Internet Printing Basics There was a request at the last BVCC meeting to review the basics of printing from the Internet. If you have ever tried clicking on the printer tool icon when you were visiting a web site, and were disappointed with the results, you might find this info helpful. The first example will show how to print a decent copy of an on-line newspaper article. The illustration shows a New York Times web page. If you look close you will find a hit target that says print this article. (Look for the print option. It is found on many web sites.)

4 Page 4 of 5 Once you select the print article option, a new web page opens this time without all of the advertisements and fancy graphics. (If the web page does not include a print option, try to highlight just the text you want. Then from the MENU BAR, select Edit, Copy. (Or, press Ctrl + C) Minimize the web page window and maximize a word processing window. Position the cursor at the desired point in the word processing document and from the MENU BAR select Edit, Paste. (Or press Ctrl + V) If there are embedded graphics or ads in the article, you might have to copy and paste a piece of text at a time, or delete the graphic part in your word processing software. If you only want to print part of the article, highlight the desired part before doing the next step. Next, from the MENU BAR, select File, Print. This will open the Print dialog box. Observe that if a selection has been made first, there will be options to print all, particular pages from a to b, or just the current selection. I very rarely use the print toolbar icon. I nearly always use File, Print (Or Ctrl + P) so that I can control exactly what gets printed. This is not only true for web pages, but for any window that contains stuff to be printed. BTW, if you want to all or part of an article to a friend, you can use Copy and Paste to move stuff from a web page to your program. Open your program and compose or write a new message. Make the program small (using the minimize gadget near the upper right corner of the window). Then open the web page (or another message) that has the desired text. Select the text and the from the MENU BAR select Edit, Copy. (Or, press Ctrl + C) Minimize the web page window and maximize the compose window. Position the cursor at the desired point in your new message and from the MENU BAR select Edit, Paste. (Or press Ctrl + V) Free Books On-Line! That s right. You can download a whole library of classic books for free. Just visit Project Gutenberg at ain_page For a number of years volunteers have been adding books to this collection. There are currently over 20,000 books, all in the public domain. This means that it is OK to download and read, or even print copies, of these books. Searching the collection is similar to using a library electronic card catalog. Just enter either an author or title in a text box. You will find a bit of everything here. For example, when I entered Mark Twain I got a long list of his publications. There are More!!!

5 BVCC January, 2008 both compressed and uncompressed files. If you have a slow connection, you might download the compressed version. These have to be unzipped with a special program before they can be read. Some materials are available also as audio files. Really, free talking books. Downloadable sheet music is also available. If you don t know where to start, you can try the top 100 list to see what downloads are popular. Another great Internet resource! FEATURED INTERNET SITES ain_page Visit the BVCC Home Page If you use any of the computers in the BVCC computer room you have noticed that when the Internet browser is opened they are set to the BVCC home page. This page is free from the advertising junk that slows down web access and also provides one click access to a number of useful web sites. Two new web links have been added to the BVCC home page recently. One link jumps to the Microsoft Virtual Earth map site. Here you can hold the left mouse button down and drag the map around until you see the part of the world you are interested in. Then you can use the magnify gadget in the upper left corner of the map to zoom in on an area. The extent of the data base defies belief! In areas where photos are available, you can even get a satellite or bird s eye view of the scene. Flying around your old neighborhood can be great fun! Another new addition to the BVCC Home page is a link to Project Gutenberg that was mentioned earlier in this issue. If you want to get to the BVCC Home page from your own computer enter: e.htm in your web browser address bar. The address is case sensitive, so watch the capitol letters in the address. In Internet Explorer, you can make any page your own home page by selecting Tools, Internet Options, and then clicking on the Use Current button. Open Office Writer This issue was prepared using the free Open Office Writer software (an alternative to Microsoft Publisher, or Microsoft Word). If you would like to try this open source software, it is available in the Computer Room. You can also download the Open Office Suite from: The file is large, so you need to have a broadband connection to download it. I have been working on a tutorial for using Open Office Writer and if you want to try Office Writer, it is available for the asking.