Upgrading your IBM PC; one or more of these add-ons can make your PC more versatile and easier to use. Russ Lockwood.
Upgrading Your IBM PC
One or more of these add-ons can make your PC more versatile and easier to use.
Some time ago, you took the financial plunge and bought an IBM PC. You lavished appropriate reverence on it, learned how to use it, and eventually became comfortable running various programs. Now you find that you have outgrown the original equipment. You need more memory to run sophisticated software like databases and spreadsheets; you want to store more information on a floppy disk; or you want to add business graphics to reports. Whatever the reason, you want to upgrade you PC, and that usually means adding up to six major components: memory board, floppy disk drive, hard disk drive, graphics board, color monitor, and keyboard.
Early models of the IBM PC had only 64K of memory on the motherboard. However, most current business software and many games require more than 64K. Assuming that the motherboard of your machine holds only 64K, you can install a plug-in memory board with an additioal 576K, for a total of 640K of memory--if you need that much
The IBM PC actually addresses up to 1Mb of memory; however, the computer reserves 360K for the graphics card, monochrome card, and ROM. If you own a later model with a 256K limit on the motherboard, you can install a memory board with an additional 384K, which again totals 640K of memory. Note that most plug-in memory boards require that you fill the motherboard completely before you can use the additional memory.
As a whole, add-on boards for the IBM PC from most manufacturers tend to be well-made and reliable; hence your main consideration are features and price. Most boards hold a maximum of either 256K or 384K of memory, although a few go up to 576K. Some manufacturs "piggyback' a second memory board onto the original to increase memory while using only one expansion slot.
The chart on page 126 compares features of plug-in memory boards.
Many memory expansion boards offer a wide array of additional functions and features such a clock/calanar, parallel port, serial port, and game port. You can think of them as multi-function boards with memory or memory boards with multiple functions.
A clock/calendar is exactly what it sounds like. The board contains a battery and automatically keeps track of the time and date whether the PC is on or off.
The parallel port connects to a printer, while the serial port, sometimes referred to as an asynchronous communications port, can connect to a modem, plotter, or other serial device. You can also use a serial port to connect the IBM PC directly to another computer with a cable. The game port connects to a joystick, paddle, graphics tablet, or other input device.
Most boards also come with software that allows you to set up a RAM disk and print spooler. A RAM disk sets aside memory to simulate a floppy disk drive, which speeds up program operations and decreases wear and tear on the drives. A print spooler sets aside memory as a buffer, which allows you to print out a file while using the computer for other operations.
Floppy Disk Drives
Two disk drives are almost a necessity, especially if you plan to use sophisticated business software. In addition, much of today's software requires double sided drives rather than single sided drives that came with the original P.C. Furthermore, double sided drives let you store twice as much data per disk as single sided drives.
The most common floppy disk drives use industry standard 5 1/4 floppy disks and come in full height and half height sizes. The two sizes offer identical performance; the only difference is that you can fit either one full height drive or two half height drives in one disk drive slot. The full height drives are generally easier to install than the half height drives.
A comparison of replacement floppy disk drives appears on page 128.
Again, the reliability of disk drives is quite good. They will eventually wear out as the heads deteriorate, but not before they have logged thousands of hours of access time, which translates into years of operation. Using additional memory and a RAM disk extends the life of the drives even further.
The main operational difference between types of disk drives is the amount of data they place on a floppy disk. The more data stored per disk, the fewer disks you need to hold the same amount of information. The disk drives listed in the chart use 48 tracks per inch (tpi) and work with standard PC-DOS. Other drives use 96 tpi and store roughly twice as much data per disk as the 48 tpi drives, but they require special software to do so.
One other feature to look for is the method of locking the disk into place. You have a choice of two types: flip-up doors and rotating knobs. We find that rotating knobs have less chance of mangling the disk and the locking mechanism tends to last longer than the flip-up doors.
Hard Disk Drives
Just as floppy disk drives use floppy disks to store information, hard disk drives use hard disks. A hard disk drive offers three significant advantages over a floppy disk drive: convenience, speed, and storage space.
Hard disk drives are generally selfcontained units although a few newer ones have removable disk cartridges. Thus, you rarely insert and take out hard disks the way you do floppy disks. Hence, you do not have to worry about losing, bending, or destroying your storage medium. In terms of speed, accessing a hard disk is faster than accessing a floppy disk, which can save you time if your software constantly accesses the disk.
Finally, hard disks store much more information than floppy disks. While a standard 5 1/4 double sided, double density floppy disk stores 360K, a hard disk stores at least 5Mb, and one manufacturer makes a 140Mb model.
Hard disk drives mount either internally, taking the place of a floppy disk drive within the system unit, or externally, sitting on the desk outside the system unit. Internal hard disk drives usually have a storage capacity of 5, 10, or 20Mb. External disk drives can hold more. The 140Mb model mentioned above is an external hard disk drive.
Just as floppy disk drive need a disk controller, so do hard disk drives. The hard disk controller takes up an expansion slot. A cable attaches between the controller and drive. Internal hard disk usually run off the power supply in the PC. External drives usually have their own power supplies.
Along with all these features, hard disk drives carry a stiff price. While you can buy a floppy disk drive for around $250, hard disk drives run into the thousands of dollars. The greater the storage capacity, the higher the cost. And do not forget to include the price of the disk controller. Another fact you should know is that backing up a hard disk is not as easy as backing up a floppy. Since a hard disk holds so much information, you need many floppies to make a second copy of your data, not to mention the time it takes the disk drives to exchange information.
An alternative to floppy disks for backing up a hard disk is a tape drive. A tape drive is exactly what it sounds like. Your data are stored on magnetic tape. The better drives have cartridges that you can take out, so you can make more than one copy of your data. If you should suffer a catastrophic hard disk drive failure and your data disappear, the tape drive can read the data into the new or repaired hard disk drive.
Color Graphics Boards
If you use the IBM PC strictly for word processing and spreadsheet work, you do not need a graphics board. However, if you want to turn numbers into graphs and pie charts, see color on your monitor, or play the arcade favorites, you need a color graphics board.
The IBM graphics board supports only a color monitor, which is fine until you want to use a monochrome monitor. For extensive word processing, a monochrome green or amber screen monitor is easier on the eyes and displays better defined characters than a color monitor. In answer to this need, many manufacturers now offer graphics boards that support both color and monochrome monitors.
Graphics boards offer different pixel resolution depending on the number of colors appearing on the screen at once. The fewer the colors, the higher the resolution, and the higher the resolution, the better defined the shapes on the screen. See the chart of plug-in graphics boards on page 130.
Some graphics boards offer a resolution far better than that of the IBM color graphics board. While this is desirable, a word of caution is necessary. Many programs do not recognize this superior resolution. Unless the software addresses the extra pixels, you see standard IBM resolution.
Two other features to look for are a parallel port and a light pen interface. The parallel port lets you send images to a printer, and a light pen allows you to "draw' images on the screen. In addition, some manufacturers include graphics utilities with their boards.
If you have the IBM Color Display connected to your PC, you already own one of the finest color monitors available. However, if you are about to install a color graphics board, you will probably want to add a color monitor to your system.
Color monitors come in two varieties: composite color and Red Green Blue (RGB) color. The difference between the two is the quality of the picture and the price.
Both monitors use three electron guns to shoot a stream of electrons to the phosphor-covered screen. One gun turns on red phosphors, one gun turns on green phosphors, and the third gun turns on blue phosphors. The big difference between a composite and RGB monitor is the signal used to control these guns.
A composite monitor works like a TV set. The monitor receives a video signal conforming to National Television System Committee (NTSC) protocols. It uses one signal to control all three guns.
An RGB monitor uses three signals, which means each gun is controlled by a separate signal. Herein lies the quality difference. Three signals transmit color intensities more precisely, producing higher resolution and sharper images. Thus, RGB monitors display clearer images than composite monitors. Of course, high resolution carries a higher price. RGB monitors cost more than composite monitors.
Just as graphics boards have an upper limit on pixel resolution, so do composite and RGB monitors. In general, the higher the resolution, the sharper the image.
When purchasing a color graphics board and monitor, you should be sure they are compatible. Both must be either composite (NTSC) or RGB. While some graphics boards boast color resolution of 640 X 400 pixels, many monitors are unable to display this resolution. Remember, the final output will be no better than the weakest link in the chain.
The biggest complaint people have about the IBM PC is its keyboard. The idea of making it detachable from the system unit is brilliant, and the 10 function keys make it very flexible. The keys have a nice, solid feel, and the aural feedback is marvelous. But, and this is a very big but, the layout of the QWERTY keyboard is rumored to have driven more than one touch typist to drink.
Frankly, most people adapted to the idiosyncrasies of the keyboard because they had no other choice. However, for those who want a different keyboard for their PC, several companies manufacture replacement keyboards.
The most important feature to "look' for is the feel of the keyboard. Keystorkes are divided into two groups of tactile sensations, hard and soft. The hard touch, which the IBM PC uses, is much like a typewriter; you must depress the key fully to input a character. The soft touch, which many of the replacement keyboards use, requires only a light tap on the key to input a character. This gives the keyboard a mushy feel, but also increases typing speed. If you switch from a hard to a soft touch, plan on taking a few hours to get used to the change.
IBM takes a lot of heat about the layout of the PC keyboard, and rightly so. Instead of using their own "Selectric standard' layout, IBM uses an altered layout, inserting extra keys where they are not expected and moving the Return key. To make matters worse, IBM labels the Return, Shift, Tab, and Backspace keys with arrows instead of words.
Most replacement keyboard manufacturers have put the keys back in their correct positions and label the Return, Tab, Backspace, and Shift keys as such. Furthermore, many manufacturers also put LED indicators on the Num Lock and Caps Lock key to tell you whether they are on or off. Some even place raised bumps on the J and F keys to help touch typists keep their place on the keyboard.
A good feature to look on a replacement keyboard is a separate set of cursor control keys. IBM makes the cursor keys double as the numeric keypad. While this is an adequate arrangement, a separate set of cursor keys, preferably arranged in a logical diamond formation, allows you to manipulate the cursor faster. The better keyboards also place special text editing keys like insert and delete either above or below the cursor keys.
The numeric keypad should have a raised bump on the 5 key. like the bumps on the J and F key, this tactile feature helps you keep your place on the keypad and speeds data entry.
One last point. Current ergonomic theory places the function keys in a row over the QWERTY keys. Some users like the function keys there, some do not. It depends on personal preference. Of course, the more function keys the merrier, although software may not acknowledge extra keys.
The Bottom Line
Almost all of the peripherals mentioned here are available from mail order houses at a discount from the suggested retail price. Although you must install them yourself, the substantial savings may offset the effort.
On the other hand, as we have discussed many times on these pages, dealing with a local retail store means that the burden of making your system work falls to someone else. Furthermore, you have a place to which to return it should it malfunction in the future.
Either way, upgrading an IBM PC is a reasonably painless and very rewarding task. With boards, drives, and keyboard installed, you can now run all the popular, sophisticated, and entertaining software available for the IBM PC.
Table: Plug-In Memory Boards for the IBM PC
Table: Replacement Floppy Disk Drives
Table: Plug-In Graphics Boards for the IBM PC