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Technology Website Directory | View information about Technology Website Directory by reviewing this area of our website. We provide a wealth of information online to help our visitors become better informed about Computer Buzz. |
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Computer Buzz Free Software Awards
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Computer Buzz has been researching the best of the freebie application programs for the past year or so, and we are pleased to announce our Free Software Awards.
To be eligible for FSA recognition, the software must belong to a mainstream program category (word processing, spreadsheet, etc.), it must be readily available to the general computer-using public (typically via Internet download), and it must be totally free of charge. Commercial programs, including shareware, don't qualify. Neither do operating systems, although most Linux and Unix OSs are free for the downloading; we considered application programs only.
We tested the most current stable version of each candidate. Alpha and beta releases were ignored. Where a package was available for more than one platform/OS and that is becoming increasingly common these days we tried to give more than one of them a look. (Incidentally, we awarded points to apps that were available for multi-platforms.) We did not evaluate any vertical market niche apps.
Take a look at our categories and winners herewith, and see what you think. Computer Buzz invites your comments about both. Have we left out some popular categories? Are some of our winners actually unworthy of the awards? We'd like to hear from y'all about this.
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Open Office
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OpenOffice.org (aka OOo or OO.o) is a free software office suite available for multiple operating systems including Linux, Windows, MacOS X, Solaris, FreeBSD, OpenVMS and IRIX. It supports the OpenDocument standard for data interchange, and can also read and write files from other common office software packages including MS Office.
This package is informally referred to as "Open Office," but project organizers report that this term is a trademark already registered, thus requiring them to adopt the clumsy "OpenOffice.org" as its formal name.
OpenOffice.org is based on StarOffice, an office suite originally developed in Germany and acquired by Sun Microsystems in August 1999. The source code of the suite was released in July 2000 with the intention of reducing the dominant market share of Microsoft Office by providing a free, open, high-quality alternative.
Computer Buzz finds that OpenOffice.org is easy to learn, and if you have ever used another office software package, you'll take to OpenOffice.org right away. If you already have files from another office package, OpenOffice.org will read them with no difficulty.
Best of all, OpenOffice.org can be downloaded and used entirely free of any license fees, because it is released under the GNU Lesser General Public License. This means you may use it for any purpose domestic, commercial, educational, or whatever. You may install it on as many computers as you like. You may make copies and give them away to family, friends, students, and employees anyone you like.
At a cost of zero, OpenOffice.org may very well be the one single most valuable software deal in all of cyberspace. Computer Buzz can not recommend this program loudly enough.
OpenOffice.org has four main components:
1) Writer is the word processor.
2) Calc is the spreadsheet.
3) Impress is the presentation package.
4) Draw is the tool to create graphics and drawings.
Official Website: www.OpenOffice.org
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Web Browsers
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The very first big "killer app" was VisiCalc, a spreadsheet for the Apple II. Not too long after that, the most commonly used PC application program was the word processor, and the spreadsheets came in second. Things have changed drastically in past two decades. The most popular program (now called a "package") these days has come to be the web browser. Email clients are the new runners-up. Let's take a quick look at some of the most popular browsers in use today and some even better ones that you may not have heard of yet.
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Office Suites for MS Windows
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An office suite, sometimes called a productivity suite, is a software suite intended to be used by clerical workers and knowledge workers. The components are generally distributed together, have a consistent user interface, and usually can interact with each other, sometimes in ways that the operating system would not normally allow.
Most office application suites include at least a word processor and a spreadsheet program. In addition to these, the suite may contain a presentation program, database tool, graphics suite, and communications tools. An office suite may also include an email client and a personal information manager or groupware package.
The currently dominant office suite is Microsoft Office, which is available for Microsoft Windows and the Apple Macintosh. It has become a proprietary de facto standard in office software.
An alternative is any of the OpenDocument suites, which use the free OpenDocument file format. The most prominent of these is OpenOffice.org for Windows, Linux, Macintosh, and other platforms. OpenOffice.org, Koffice, and Kingsoft Office support many of the features of Microsoft Office, as well as most of its file formats and have spawned several derivatives such as NeoOffice and StarOffice, a commercial version by Sun Microsystems.
Let's take a quick look at some of the currently available office suites for Windows.
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Office Suites for Mac OS X
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The most popular office suite for the Macintosh is certainly Microsoft Office After all, both MS Word and Excel made their debuts on the Mac and were later ported to Windows. But it is a fact that Mac users tend to be suspicious of anything that comes out of Redmond, Washington. So, MS Office does not enjoy the obscene software monopoly amongst Appleheads that it does with WinDOS zombies. There's no shortage of good office suites for the Mac; all of them except for MS Office, of course are affordable, and a couple of them are free.
Let's take a quick look at the field.
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Office Suites for Unix/Linux
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There are not just a lot of commercial office suites available for users of Linux/BSD/Solaris/Unix, and there's a reason for that. Aside from the fact that these folks rarely wear matching socks and have trouble locating their own cars in a small parking lot, they tend to have a deep and abiding distrust of any form of software that smacks of capitalistic profit. They worship the holy grail of free and open softwear. Now don't get us wrong--we here at Computer Buzz love a free lunch just as much as the next bum. In fact, there's a big sign on the computer lab wall that reads: "The three sweetest words in the English language are: FREE, TAKE ONE!"
Long story short: most office suites for Linux and Unix are freebies. But that doesn't mean that they're not ready for prime time. One of them, OpenOffice.org, is arguably the best software deal in the Solar System.
Click the adjacent image, and let's take a look at what's available.
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Alternative Operating Systems
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Part of our mandate here at the Computer Buzz Labs in Dallas is to test and evaluate some of the more important computer software packages that are available today. There's no piece of software that is more important to your computer than its operating system. But most computer users are familiar with only Windows or Macs (and only occasionally both) and know little or nothing about the myriad of other OSs that are available to us nowadays, usually at no cost.
As you can tell by looking at the list of alternatives that we have assembled for you, we have taken the attitude that Windows (all versions right up to Vista) and the Mac OS (including both "Classic" and OS X) are mainstream OSs and that just about all the others are alternatives to them. We are not going to waste your time or our own by considering earlier operating systems that are no longer realistic alternatives, such as Apple DOS, CP/M, PC/MS-DOS, Pro DOS, Amiga DOS, Radio Shack's TRS-DOS, Apple's Lisa, GEOS, etc.).
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Linux Operating Systems
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Linux is not really and truly an OS. It's a software kernel (written by University of Helsinki undergraduate student Linus Torvalds in 1991) bundled with GNU userland libraries (written mostly by Richard Stallman of MIT in the mid- to late 1980s) which can be used as the basis for UNIX-like operating systems.
Linux's international mascot is Tux the penguin (shown here).
At present, there are more than 600 nominal Linux OSs available, most of them totally free because Torvalds has made his copyrighted Linux code available under the GNU Public License (GPL). In practice, this means that Linux is an open source piece of software, and anyone can use it and/or modify it without paying for it. But that double-edge sword cuts both ways if you publish your own knockoff version of Linux, you are not allowed to charge anybody else for it either. And so, Linux's greatest strength is, at once, its most abysmal and debilitating weakness.
It has a reputation for stability, and so is popularly used in web servers of all kinds. Just in recent years, it has gained remarkable popularity as a desktop OS for PCs. Many flavors of Linux are also compiled for older PowerPC Macs, although Apple's decision to go exclusively with Intel CPUs has pretty well put the kabosh on that practice.
There are three main branches of Linux at this time: Debian, Red Hat/RPM, and Slackware. Let's have a quick look at them.
(Adjacent image shows "Tux," the official Linux mascot.)
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VMWare Fusion
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Here at Computer Buzz Labs in north Dallas, we put a lot of hardware and software through their paces. The last couple of years or so, much of that software has consisted of what we call "alternative operating systems"--anything other than Windows or Mac OS X. We usually assign one OS to a single computer and let it take over the entire hard disk during the evaluation tests.
But recently we think we've come up with a better idea. It involves the humble Apple Mac Mini and some highly innovative software from VMware and Parallels. These two software publishers have come up with somewhat dissimilar methods of letting us install a couple--or a couple of dozen--full blown operating systems on a hard disk that actually is under the control of Mac OS X.
It all started a couple of years ago when Apple Computer dumped the PowerPC chip and began using Intel chips exclusively in their Mac boxes. Shortly thereafter, Apple started including a little program called Boot Camp with every Mac they sold. Boot Camp allows you run Microsoft Windows on your Intel-based Mac. It's not as convenient as it could be, because you can't run Windows and the Mac OS concurrently. You have to decide as your Mac is booting up every time whether you're going to boot into Windows or OS X. And, of course, you have to bring your own copy of Windows along; Steve Jobs is not about to go around handing out free copies of Bill Gates' software.
Within a few weeks of Apple's launch of Boot Camp, Switzerland-based Parallels, Inc came out with Parallels Desktop for Mac ("PDM" or "Parallels" for short). PDM was originally touted as an improvement over Boot Camp that would let you run Windows on a Mac simultaneously and side by side with the Mac OS. Not a bad idea for Apple-heads who needed to occasionally run a Windows app but didn't want to shell out for a whole nuther computer. Oh, and by the way, Windows was not the only other OS you could run on your Mac using Parallels. Most versions of Linux would run too, as would Solaris and various versions of BSD Unix. All of a sudden, this virtualization thing was getting interesting.
Quickly thereafter, VMware Inc (NYSE: VMW), a Palo Alto-based company founded in 1998, got into the act with their Fusion program. Like Parallels, Fusion is a virtualization app that allows Mac users to run Windows side by side with OS X. And like Parallels, Fusion can also accommodate "guest" operating systems like Linux and BSD.
Computer Buzz purchased the most recent available versions of Parallels (3.0) and Fusion (2.0). We were not all that interested in the way they run Windows; Windows runs reasonably well on both of them, and other evaluation teams have flogged that old horse to death. We wanted to see how PDM and Fusion could handle the ever-more-sophisticated Linux and Unix distributions that are coming out daily (and almost hourly).
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BitTorrent: File Sharing for the 21st Century
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BitTorrent is a peer-to-peer file sharing protocol, a method of distributing large amounts of data without the original distributor incurring the entire costs of hardware, hosting, and bandwidth resources. Instead, when data is distributed using the BitTorrent protocol, each recipient supplies pieces of the data to newer recipients, reducing the cost and burden on any given individual source, providing redundancy against system problems, and reducing dependence on the original distributor. This protocol is was designed by Bram Cohen in 2001. It is now maintained by Cohen's company BitTorrent, Inc. Usage of the protocol accounts for significant traffic on the Internet, but the precise amount is difficult to measure.
A BitTorrent "client" is any program that implements the BitTorrent protocol. Each client is capable of requesting, preparing, and transmitting any type of computer file over a network. Confusingly enough, the first BitTorrent client was eponymously named "BitTorrent."
A "peer" is any computer running a copy of any BitTorrent client. To share a file or group of files, a peer first creates a "torrent" file. This small file contains metadata about the files to be shared and about the "tracker," the computer that coordinates the file distribution. Peers that want to download the file first obtain a torrent file for it, and connect to the specified tracker, which tells them from which other peers to download the pieces of the file.
Here's how it works: Users browse the web to find a torrent of interest, download it, and open it with a BitTorrent client. The torrent file causes the client application to connect to the specified tracker(s), from which it receives a list of peers currently transferring pieces of the requested file. The client then connects to those peers to obtain the various pieces. Such a group of peers connected to each other to share a torrent is called a "swarm." If the swarm contains only the initial seeder, the client connects directly to it and begins to request pieces. As peers enter the swarm, they begin to trade pieces with one another instead of downloading directly from the seeder.
Though both protocols ultimately transfer files over a network, a BitTorrent download differs from a classic full-file HTTP request in several fundamental ways. These differences allow BitTorrent to achieve much lower cost, much higher redundancy, and much greater resistance to abuse than a regular HTTP server. However, this protection comes at a cost: downloads can take time to rise to full speed because it takes time for enough peer connections to be established, and it takes time for a node to receive sufficient data to become an effective uploader. As such, a typical BitTorrent download will gradually rise to very high speeds, and then slowly fall back down toward the end of the download. This contrasts with an HTTP server that, while more vulnerable to overload and abuse, rises to full speed very quickly and maintains this speed throughout.
There are already more than three dozen BitTorrent clients written in a variety of programming languages and running on a variety of computing platforms, and more are popping up every month. We can't cover them all, but we have selected several notable ones for your consideration.
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iPhone from Apple
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Apple hit a grand slam over the center field wall in mid-2007 with the introduction of the iPhone. Even its goofy name couldn't keep the iPhone from being a smashing success. Everyone agrees: Apple has done it yet again.
It's far more than a phone; it's an iPod (of course), a camera (aren't they all?), an email client, a Web browser, a contact manager, a photo album, a stock ticker, and more. Everything it does, it does better than just about any of its competition, and it does it with only a single hardware button on its face.
Computer Buzz has a few gripes about the iPhone, albeit fairly minor ones. The smallish on-screen QWERTY key pad that some of its apps require will be a bit of a challenge for most adult males and large women with fat fingers; its telephone function does not include voice dialing, and the speaker-phone function is not nearly loud enough; the battery is adequate but not user replaceable; the phone has to be bundled up and sent back to Apple for that; unlike its iPod cousin, the iPhone's sonic output plug is recessed so that a clunky adapter (not included) is required for most headphones and/or external speakers; and the price;$400 for the less expensive model reminds us that this is cutting edge technology.
The iPhone is easily the smartest of all the smart phones. It's hard to say if it's really a PDA in smart phone clothing, or a very sophisticated iPod, or a...? Whatever it is, telephony is one of its lesser functions. It excels at almost everything it essays, and Computer Buzz gives it two thumbs up.
Official Website: www.Apple.com/iPhone/
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CPUs : A Basic Primer
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Now that Apple has dumped Motorola as the supplier for their CPU chips, the only two major manufacturers of central processing units (CPUs) left standing are Intel and AMD. To be sure, Motorola is not completely out of the business, and Sun Microsystems still designs and makes their own SPARC chips, but those are small potatoes in the grand scheme of things.
Except for a few geeks who build their own computers from scratch, nobody cares about buying individual CPU chips. But when shopping for a new or used computer, few things are more fundamentally important than the CPU that powers the box. For your edification, Computer Buzz has assembled a few brief topics that you might want to consider when shopping for your next desktop or laptop.
(Historical note: Adjacent image shows ancient Zilog Z80 CPU, considered by many to be the chip that started it all.)
Official Website: www.AMD.com
Official Website: www.Intel.com
Official Website: www.Motorola.com
Official Website: www.Sun.com
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Monitors and Displays
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Once upon a time, if you wanted a really first class computer monitor, you just went out and bought a flat screen Sony Trinitron, and that was all there was to it. Sony is still a player, but the competition is hotter than Sony ever imagined.
New display models come out every week, so it's hard for even someone like PC Magazine or Consumer Reports to keep up with who's on first. Here is a listing of some of our favorite players in the monitor/display category these days:
Samsung Official Website:www.Samsung.com
NEC Official Website:www.NEC.com
Apple Official Website:www.Apple.com
Dell Official Website:www.Dell.com
HP Official Website:www.shopping.HP.com
ViewSonic Official Website:www.ViewSonic.com
LG Official Website:www.LGE.com
eMachines Official Website:www.eMachines.com
Westinghouse Official Website:www.Westinghouse.com
Gateway Official Website:www.Gateway.com
Princeton Official Website:www.PrincetonGraphics.com
That said, the big difference between one display and another these days revolves around older technology CRTs (cathode ray tubes) and FPDs (flat panel displays utilizing any of several newer technologies). Let us explain:
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Garmin Nuvi 660 is a BIG winner
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GPS (Global Positioning System) units are not really computers, but in the last half dozen years or so they have become, for all practical purposes, computer peripherals. As such, they are fair game for Computer Buzz's review and evaluation team.
Computer Buzz has a couple of bikers on our staff, so we decided to let them have a go at a unit that can be mounted on a motorcycle. After some deliberation, the GPS unit we chose was the upscale Garmin Nuvi 660 with a street price of about $550. The motorcycle we chose was a venerable Kawasaki KLR 650. The Nuvi can run for the biggest part of a day on its sealed rechargeable battery, but the KLR can be easily modified with one or more cigarette lighter style power takeoff sockets that the Nuvi can plug into. The Nuvi has a snap-on ball and socket mounting bracket on the back that can be mounted/attached as easily to your motorcycle's handlebars as to your car's windshield or dashboard.
The KLR falls into the catagory of "dual sport motorcycle" which basically means that it is a light duty dirt bike that is street legal. Everyone who takes a dual sport motorcycle off-road should think seriously about packing some sort of a GPS unit to find their way back to civilization. Computer Buzz thinks that the Garmin Nuvi is one of the better units--though certainly not the cheapest--on the market today. Initial setup is simple and straightforward. If need be, it can communicate with your computer (Macs as well as PCs) via a USB port.
Let's be honest; we love getting off road with the KLR, but the large majority of our motorcycle mileage is on the asphalt. So we ponied up a few extra bucks for Garmin's optional Plug & Play Street Maps software that comes on a microSD card. We just replaced the stock SD (SanDisk) card that came with the Nuvi with the P & PSM card. It's easier than changing the battery in a cheap watch. Most motorcyclists will never need the extra data on the P & PSM card, but it's nice to have in an emergency.
Off the pavement, the KLR's stiff suspension is pretty hard on electronic gear, solid-state circuitry notwithstanding, but the Nuvi held up nicely and didn't complain a single time. We initially had some concerns about that, because seven or eight years ago a much earlier Garmin GPS became erratic and eventually inoperable when we subjected it to similar rough treatment in the high elevations of Colorado. We're pleased to report that the Nuvi is one tough unit that can take a licking and keep on ticking.
Menus on the Nuvi are straightforward and intuitive. You can easily adjust the screen brightness, sound volume, color mode, or call up a simple calculator; you can even switch your vehicle image in the center of the screen from a car or a triangle to a motorcycle. Needless to say, Computer Buzz does not recommend that you fiddle with the on-screen controls while your motorcycle is in motion.
Your can pay more for a Garmin Nuvi--the Nuvi model 880 lists for $899--but we think the Nuvi 660 is one of Garmin's best bang-for-the-buck deals right now. The 660 works as well, or better, on the dashboard of a car as it does on the handlebars of a motorcycle, and we hereby give it the Computer Buzz Seal of Approval.
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Circular Storage: Hard Disks and Optical Drives
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For most home computer users, storage media boil down to two main categories: hard disks (HDs) and optical disks (CDs and DVDs). There are other choices, of course, like tape drives and flash drives, but HDs and opticals are really the big ones. Computer Buzz has taken a close look at both of them.
There are currently three broad types of hard disks available either as OEM or aftermarket products. These are: Advanced Technology Attachment (ATA), Serial ATA (SATA; rhymes with "beta"), and SCSI (pronounced "scuzzy").
The largest hard drive you could buy in 2007 was 1 terabyte (TB). Four-TB drives are predicted to be available by 2009. The standard speed of most hard drives in 2007 was 7200 rpm, but 10,000-rpm drives are available, and you can even find a few that run at 15,000 rpm. Problem is, at this point in hard drive development, you must trade off speed for capacity, i.e., slow drives hold more data, and fast-spinning drives hold less. That may change in the future.
The vast majority of all hard disks on Earth are made by the following manufacturers:
Compaq/HP Official Website: www.HP.com
Fujitsu Official Website: www.Fujitsu.com
Hitachi Official Website: www.Hitachi.us
Seagate/Maxtor Official Website: www.Seagate.com
Samsung Official Website: www.Samsung.com
Western Digital Official Website: www.wdc.com/en/
Optical disks come in two flavors, CDs and DVDs.
The technical specs of storage media are mind-boggling, but we'll try to stick to the important points and keep this discussion brief and comprehensible.
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Wireless Routers
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Wireless routers with Internet connection sharing, networking, and firewall features are an alternative to wired routers or networking software. Wireless routers are actually wired routers with wireless access points built in so you can have wired and wireless at the same time. Wireless routers are not as secure as hard wired.
Networking products from different companies are practically guaranteed to support each other because they conform to the same standards; they have to. And because they conform to the same detailed standards, there is little that companies can do to differentiate their individual products. Standardization is a great equalizer, so companies try to distinguish their products by combining multiple features into one device, as well as by offering different pricing and support strategies.
The latest generation of wireless routers is based on the Draft 2.0 802.11n agreement. The "n" is what sets it apart from earlier 802.11g routers. N routers are capable of faster speeds and longer ranges that the older G routers.
Throughput, or bandwidth, is related to speed. Fast connections can offer high throughput if they're properly configured, but high throughput also means that there are no constrictions or bottlenecks for network services (such as access to Internet connections, DHCP services, DNS, etc. ). The design of high-throughput systems begins with sufficient transmission and processing speed and extends to optimal addressing and network organization.
Let's take a look at some of the wireless routers that are in the news these days.
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Performance Video Cards
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Video cards are the circuitry that allows your computer to communicate with your monitor so that it can display what the computer is doing. Once upon a time, video cards were "2D," or "3D," but today's are mostly "2D/3D" combos. The 3D is useful for gaming, but in some applications, it can be useful in 3D modeling, etc.
Video cards have their own high speed processing chips that make graphics look more realistic. The many video cards out there are based on a much smaller number of chipsets. Different companies buy these chipsets and then manufacture their own versions of the cards based on the chipsets. For the most part, video cards based on the same chipset with the same amount of RAM are very closely equivalent in performance. However, some brands will use faster memory or other small optimizations to tweak the speed.
The addition of other extras like "dual heads" (support for two monitors) or better cooling fans may also differentiate the various brands of cards.
At any rate, the first decision that you have to make is what chipset you want your video card to use. If you're not twisted off into games, then the choice of chipset is no big deal; just about any of them will do for the 2D desktop applications. There's no point in paying over $100 for a video card if you don't plan to play a lot of games.
Here are some of the things that Computer Buzz suggests you keep in mind and look for when shopping for an upgrade video card:
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Smart Phone Rankings
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Computers, cell phones, digital cameras, and PDAs have all been morphed into a gizmo that is being loosely called a "smart phone," at least until a better name comes along. You can typically use a smart phone to store contact information, check your junk email, take fuzzy photos, play solitaire, and maybe even place a phone call.
Computer Buzz has taken a close look at the general flavors of smart phones that are currently available, and we have ranked them according to our totally subjective whims. As always, we invite your comments.
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Wireless Internet Cards
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Most laptops nowadays come with Internet wireless connectivity right out of the box. And so do many desktop computers. But this was not always the case. Once upon a time, you had to select an add-in wireless card in order to get on the Internet without a Cat-5 Ethernet umbilical cord. Many of those machines are still around, and the Computer Buzz labs have been experimenting with them.
Wireless cards vary greatly in their ease of use and compatibility factors. Our unanimous choice for PCMCIA cards (for laptops of all descriptions) is the ubiquitous Cisco 350 series. It is arguably the most popular wireless card of all time and justifiably so. It supports the 802.11b wireless protocol, which means it can transmit a max of 11Mbps, not the fastest thing going, but perfectly adequate for most purposes.
The 350 "just works" right out of the box. Macs and PCs are, of course, a given. But we have tested the 350 series with a dozen different implementations of Linux, and the cards have worked flawlessly without even requiring us to install driver software. It doesn't get much slicker than that.
Other wireless cards we have tested (Broadcom comes to mind) have flatly refused to work without additional drivers and/or firmware upgrades. Oftentimes the computer just refuses to see the card after it has been installed.
The Cisco 350 also comes in a PCI configuration for desktops, and it is just as easy to install and get up and running as the PCMCIA model. It fits in an internal slot and has a little antenna that sticks out the back of the box. Again, it's (usually) plug-and-play simplicity at its best.
Both kinds of 350 cards are widely available on eBay at bargain prices, i.e., about US $50 or so. Computer Buzz rates the Cisco 350 wireless card as a "Best Buy."
Official Website: www.Cisco350.com
Adjacent image shows Cisco 350 PCMCIA card for laptop computer.
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DVI connectors
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The Digital Visual Interface (DVI) is a video interface standard designed to maximize the visual quality of digital display devices such as flat panel LCD computer displays and digital projectors. It is designed for carrying uncompressed digital video data to a display.
Previous standards such as the analog VGA were designed for CRT-based devices. CRTs are rapidly disappearing and being replaced with LCDs, so Computer Buzz strongly recommends that you become familiar with the basics of DVI technology at your earliest convenience. Read on.
With a basic single link DVI cable, the largest resolution possible at 60 Hz is 2.75 megapixels which, for all practical purposes, allows a maximum screen resolution at 60 Hz of 1915 x 1436 pixels (standard 1.33 ratio), 1854 x 1483 pixels (1.25 ratio) or 2098 x 1311 (widescreen 1.6 ratio). Some DVI connectors also have provision for a second, or "dual" link, allowing even higher resolution. When more bandwidth is required than is possible with a single link, the second link is enabled, and alternate pixels may be transmitted on each, allowing resolutions up to 4 megapixels at 60 Hz. The DVI specification mandates a fixed single link maximum pixel clock frequency of 165 MHz, where all display modes that require less than this must use single link mode, and all those that require more must switch to dual link mode. The second link can also be used when more than 24 bits per pixel is required.
In general, cable lengths from 1 to 15 feet (4.5m) will work for displays at resolutions of 1920x1200. Cable lengths up to 50 feet (15m) can be used with displays at resolutions up to 1280x1024.
The DVI connector contains pins to pass the DVI-native digital video signals. In the case of dual-link systems, additional pins are provided for the second set of data signals. As well as digital signals, the DVI connector includes pins providing the same analog signals found on a VGA connector, allowing a VGA monitor to be connected with a simple plug adapter. This feature was included in order to make DVI universal, as it allows either type of monitor (analog or digital) to be operated from the same connector.
The DVI connector on a device is therefore given one of three names, depending on which signals it implements:
-DVI-D (digital only)
-DVI-A (analog only)
-DVI-I (integrated, digital & analog)
The connector also includes the provision for a second data link for high resolution displays, though many devices do not implement this. In those that do, the connector is sometimes referred to as DVI-DL (dual link).
You can easily tell exactly which kind of DVI connector you are dealing with by simply glancing at the pin configuration.
The long flat pin on a DVI-I connector is wider than the same pin on a DVI-D connector, so it is not possible to connect a male DVI-I to a female DVI-D by removing the 4 analog pins. It is possible, however, to connect a male DVI-D cable to a female DVI-I connector. Many flat screen LCD monitors have only the DVI-D connection so that a DVI-D male to DVI-D male cable will suffice when connecting the monitor to a computer's DVI-I female connector.
DVI is the only widespread video standard that includes analog and digital transmission options in the same connector.
(Adjacent image shows dual-link DVI-D male cable connector.)
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