Major Computer Hardware and Software Categories

By Ed Dalton

Digital Cameras

• Picture quality (usually expressed in terms of resolution)
  
• Number of pictures that can be stored in the camera at one time
  
• Type of storage medium - flash memory, floppy disk, and so on
  
• Picture format - for example, MPEG
  
• Preview capability - for example, an LCD screen
  
• External interfaces - Computer, TV, and so on

Before shopping for digital cameras on eBay, you might consider going to a retail store and letting a salesperson show you various models, and the pros and cons of each feature. This will also give you some idea of the current retail prices.

If you want to be even better prepared, consider reading the book, Digital Photography for Dummies, by Julie Adair King, published by IDG books.

Hardware

If you live near some large computer stores, you can visit some of them to familiarize yourself with what is on the market, and to get an idea of the current prices. Alternatively, you can examine the listings in one of the mail-order computer catalogs.

General - The Hardware: General subcategory is a place where you will find all kinds of fascinating products. Some of the listings are simply misplaced items that really belong in other categories, however, there are many wonderful accessory items here. Some of these items include unique mouses or mouse pads, print cartridges, cables, older computers and parts, and telephone gadgets. You can enjoy browsing through the listings, or, if you have something specific in mind, use the eBay search feature.

Books - The Hardware: Books subcategory is a great place to find older books that may not be in stores anymore. It is also a good resource for manuals and catalogs related to some of the brands - such as Amiga, Atari, and Commodore - that are not in the mainstream anymore.

You will also find some books listed in their corresponding hardware and software subcategories.

CPUs -In the Hardware: CPUs subcategory you will find computer cases, power supplies, processor chips, and motherboards that you can use if you want to build a computer or upgrade one. It is very educational to do this, and if you are serious about it, you might consider buying one of the books on building and upgrading computers listed in the Books section of this guide.

Up until about two years ago, many people built computers from parts and saved a lot of money. Now, however, there is somewhat less of a saving and somewhat more risk involved. There is less of a saving because the prices of new computers have come way down. There is more risk, because, with faster bus speeds, there is less tolerance for variations in bus timing, so that it is not a sure thing that components bought from different manufactures will work well together.

If you are willing to take the risk, however, you will find that you learn a lot in the process of building a computer, and that may be worth it, even if the computer itself doesn't work.

Drives - In the Hardware: Drives subcategory you will find CD-ROM drives, hard disk drives, and removable media drives, such as Iomega Zip drives, SyQuest drives, and floppy disk drives.

Generally, there is not a lot of risk in replacing or adding a hard disk to your computer. There is often a need to do this, as you add more software, and you find that what originally seemed like plenty of hard disk capacity is now almost all used up.

Hard disks come in two main types - IDE and SCSI. You can not mix and match. Before you buy a new hard disk, find out whether the one in your computer is IDE or SCSI, and buy one of the same type.

SCSI drives can be used in both PCs and Macintosh computers, but they have to be initialized for the specific type of computer. You can't just unplug a SCSI drive from a PC and attach it to a Macintosh. However, a knowledgeable person can reinitialize it for you.

Input Peripherals - The Hardware: Input Peripherals subcategory includes cameras, microphones, keyboards, mouses, game controllers, scanners, and other equipment that helps you put data into your computer, or control some of your interaction with your computer.

There are many issues concerning compatibility of particular devices with particular kinds of computers, and particular ports on those computers. If you have any doubts here, communicate with the seller to resolve them.

Macintosh - For years the Macintosh computer was the computer of choice for graphics professionals and multimedia enthusiasts. However, with the advent of Windows 95, the PC became capable of performing on a par with the Macintosh, and the major software developers began selling graphics and multimedia products for both Macintosh and PC.

An advantage of the Macintosh is that a SCSI interface is standard, so it's easy to add a device such as a scanner - basically, you just plug it in, select your SCSI ID, and install the software. An advantage of the PC is that extra memory is usually less expensive and easier to install.

At this point in time, it's a matter of personal preference whether you choose the PC world or the Macintosh world.

Memory - The Hardware: Memory subcategory consists primarily of random access memory (RAM) for PCs. For Macintosh memory you can search for "Macintosh" within the Hardware: Memory subcategory. You can also search for "memory" within the Hardware: Macintosh subcategory.

The important thing to do when buying memory is to find out exactly what kind of memory module your computer requires, and to buy specifically that kind. Some of the common RAM memory types are:

• 30-pin SIMMs - common in older computers (up to about the 486 vintage)
• 72-pin - SIMMs these come in two main types - ordinary and "extended data out" (EDO).
• 168-pin DIMMs - this is the usual packaging for "synchronous dynamic RAM" (SDRAM).

SIMM is short for Single Inline Memory Module. DIMM is short for Dual Inline Memory Module. These terms refer to the way the connector pins are arranged.

Modems - The Hardware: Modems subcategory includes modems and fax-modems. The latter can send and receive faxes in addition to acting as modems. You can use a modem to connect to an Internet Service Provider (ISP) via ordinary phone lines. In the last few years, typical modem speeds have progressed from 1200 bits per second (baud) to 9600, 14.4K (14,400), 28.8K, 33.6K, and (presently) 56K.

Anything slower than 56K will be very inexpensive now, because people are upgrading to 56K and lots of the slower modems are for sale, especially on eBay.

The situation for 56K is a little bit complex. When 56K modems first came on the market, there were two competing standards - X2 (by U.S. Robotics) and Flex. These were not compatible with each other, so if your modem used one standard and your ISP used the other, then you would not get the benefit of 56K operation. Most likely you would connect at 28.8K.

Recently, a new standard, called V.90, has been adopted, and eventually all the ISPs will change to that. If you are buying a new 56K modem, you should probably go for the V.90. Some V.90 modems can also function as X2, and some can also function as Flex, so if you buy the right one you can enjoy 56K operation now, while waiting for your ISP to upgrade to V.90.

Another decision that you will have to make is whether to use an internal modem or an external one. Internal modems cost a little less, but they use up one of your expansion slots. External modems are slightly easier to install, but they use up one of your serial ports.

If you buy an internal modem, make sure that it fits the kind of bus that your computer uses. Older PCs use an ISA bus or an EISA bus. Older Macintoshes use a NuBus. New PCs and Macintosh's both use the PCI bus.

If you have a laptop computer that does not have a modem built in, you can use a PCMCIA modem. It is about the size of a credit card, and plugs into one of your PCMCIA slots.

Make sure that the modem software that comes with the modem is compatible with the operating system that your computer uses.

Another distinction is shadow-mask picture tube versus Trinitron tube. Trinitron monitors cost a little more, and are generally regarded as being a little better, but the difference is not extreme.

For high-resolution color graphics, video display boards should have at least 4 megabytes of video RAM (VRAM). If you are going to play computer games, you may need a very high-end video board. These devices are constantly evolving. It would be best to read trade publications to keep up.

The most common type of network for small computers is called Ethernet. Earlier versions of Ethernet transferred data at 10 megabits per second. Today, 100 megabits per second is normal.

A network adapter card usually comes with software and detailed instructions telling how to configure a simple network.

Besides these simple Ethernet cards and hubs, there are other kinds of more sophisticated equipment listed on eBay. It would be best to study the manufacturer's documentation or books specifically on networking before buying any such products.

Portable - The Hardware: Portable subcategory includes laptop computers, notebook computers, wireless modems, and PCMCIA cards. PCMCIA cards are the small credit-card size devices that let you use various accessories with your small portable computer.

The displays for laptop computers vary greatly from one model to another. Some displays have an annoying slowness to them, so that moving objects appear to leave trails. It is a very good idea to actually see the particular types of displays before deciding which to buy.

Also, there are various kinds of pointer devices, that take the place of a mouse. Some people prefer the trackball device. Others prefer a touchpad or post type. You should certainly experiment with the various types to see which you like best.

When you buy a printer, make sure that it has the right kind of interface for the way you will use it. Some common interfaces are:

• Centronics interface, which connects to the parallel port on a PC.
  
• Apple serial interface, which connects directly to a Macintosh computer or an AppleTalk network.
  
• Ethernet interface, which connects to an Ethernet network.

Some computers have a dual interface, and will work with both PC and Macintosh computers.

Computer printers have evolved through daisy-wheel printers (now extinct), dot matrix printers (still around - mostly used for multipart forms in commercial applications), inkjet printers, and laser printers.

Virtually all small computers now use inkjet printers (for color) and/or laser printers (for black and white). Laser printers originally cost about $2000, but now very nice ones can be purchased for less than $400. The inkjet printers start at around $100, and are really excellent.

You can become more familiar with this terminology just by reading the detailed descriptions of many listings, until you begin to speak the language.

A few of the listings are for other kinds of video devices - for example, video capture boards, that process inputs from a video camera or a VCR, and support video editing. DVD (digital versatile disc) players also sometimes appear in this category.

If you live near some large computer stores, you might want to visit some of them to familiarize yourself with what is on the market, and to get an idea of recent prices. Alternatively, you can examine the listings in one of the mail-order computer catalogs.

Books - Most of the books listed in the Software: Books subcategory teach you how to use a particular software product. The best way to find items in this subcategory is to search for the name of the software that you are interested in. However, browsing through the listings might also be worthwhile. You may find something really helpful, even if it isn't what you started out to find.

You can find additional books listed in the other software categories.

This is a subcategory that is particularly good for browsing.

Software such as Adobe PageMaker and QuarkXPress are typical desktop publishing programs.

You can also find a lot of fonts, clip art, and stock photography in this subcategory.

Browse through this section to get an overview of what is available.

Virtually all computer games are for PC - relatively few are for Macintosh. Remember that to run many of the best computer games, you need a really high-performance computer, with a high-performance video board.

Keep in mind that you need the right kind of player to play a particular Sega or Nintendo game. For example, Nintendo games might be for the Super NES system, the Game Boy system, or the Nintendo 64 system.

If you have any doubt as to which player is required, ask the seller.

Services

Most of the listings have something to do with the Web - help with Web site content or management, domain names, and so on.

This is a good category for browsing.

Business opportunities are another group of items that tend to show up here.

There also appear to be a few Web businesses for sale.

The preceding material was written by Ed Dalton. These are the opinions of the author, not the opinions of eBay, and therefore eBay does not validate the accuracy of or endorse these opinions.