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COMPUTER BITS BY DARREN YATES Adding a CD-ROM drive to your computer Over the last 12 months, the price of CD-ROMs has plum­meted. For around $300 or less, you can buy & install a high-speed CD-ROM & gain access to a whole new world of software. What’s more, it’s easier to do than you think. Just as the CD (or compact disc) revolutionised the music industry, so is it having the same effect on the computer indus­try. These days, you can’t walk into a computer store without some mention of CD-ROM. And just about every advert that you see for computers makes some mention of either CD-ROM or the current buzzword “multimedia”. What’s “multimedia”? It simply refers to a computer that has a CD-ROM drive, a sound card and a couple of loudspeakers for sound effects. This sort of system enables the integration of high quality sound, animation, text, photographic-quality images and graphics for all sort of applications. And because it’s played back via the computer, it allows for user interaction. CD-ROM advantages So what’s so good about CD-ROM? Well, for starters, it gives you fast access to more information that you could ever imagine. This information can include telephone directories, atlases, dictionaries and even complete encyclopaedias. If you’re in business, you can buy a complete telephone directory for the entire country on CD-ROM, not just for your city or district. It may not sound exciting at first glance but it gives you access to any business phone anywhere in Australia and is much easier to store than 20 or 30 telephone books. Games take on a whole new meaning as well. And if you have a sound card, you get the full range of sound effects – not just beeps and squawks. In fact, some of the latest releases come with complete soundtracks like big-budget movies. Graphics, too, are also improved, with the possibility of moving pictures. With 600-odd megabytes (Mb) on a standard CD-ROM and up to 1.2Gb on a double-speed CD-ROM, there is almost no limit to what you can put on them. CD-ROMs also have the ability to produce CD-quality sound. You can even obtain shareware software which enables you to use your CD-ROM drive to play ordinary music CDs, either through a stereo headphone socket on the front of the drive or via a sound card and loudspeakers. Naturally, this can be done in the back­ground, allowing you to use the computer as normal for other work – like writing articles on how to install CD-ROMs. Another big advantage of CD-ROMs is their ability to store large software programs. Indeed, many software manufacturers, including Microsoft, are beginning to sell software on CD-ROM. For example, Microsoft’s Video for Windows now comes with a CD-ROM containing video images on everything from Space Shuttle launches to music clips to balloon flights. A complete version of CorelDraw 5 is also available on a set of three CDROMs. This not only saves you from having to install the program from multiple discs but also provides you with access to hundreds of fonts (825 in all) and thousands of clipart images. In fact, CorelDraw is really a number of programs all bundled together in the one package. Indeed, many programs are now so large that CD-ROM is really the only sensible way to go. Providing users with 15 or 20 floppy discs to install a program is cumbersome when the job can be done with just one CD-ROM and the manufacturer can include a range of other useful utilities as well. The latest innovation to come from CD-ROMs has been Kodak’s introduction of the Photo CD. When you’ve finished exposing a roll of 35mm colour film, you give it to Kodak who’ll then pro­cess it and give you back a nice new shiny CD-ROM with your photos on it. What’s more, provided it’s a “multi-session” type, you can take the CD-ROM back with your next film and they can load the new frames onto it. This makes it extremely easy to load pictures into desktop publishing programs such as PageMaker and Quark Express. We use this system on occasions for some of the photos that appear in Silicon Chip. Adding a CD-ROM drive Adding a CD-ROM drive to your computer is not that hard to do, although you do have to know what you are doing. About the hardest thing is shopping around for the best price. As a result of competition, prices have February 1995  53 About the only thing missing from this multimedia kit is a pair of speakers (or headphones) to provide the sound effects. Note that the items pictured are about 2.5 years old & some, at least, will have been superseded. fallen like a brick in the last few years. When we first reviewed a CD-ROM system about two and a half years ago, the price was around $1500. Today, stores are tripping over themselves to sell you a complete multimedia system for less than $400. And if you’re looking for a bare-bones CD-ROM system with just the driver card, drive and driver software, you can pick up one for as little as $239. That’s cheaper than a 200Mb hard drive! The basic CD-ROM is the same size as a half-height 5.25-inch floppy drive and is designed to fit into one of the drive bays inside your PC. Basically, you have to mount the drive in posi­ tion, install an adapter card and connect the power supply and interface cables. Before starting work, be sure to unplug the computer from the mains. This done, remove the lid and make a note of where all the existing cables to the drives go, just in case you have to temporarily disconnect some of them. Next, locate a suitable spare 5.25inch bay and unclip its front plastic cover. You may have to do this by applying a modest amount of pressure to the cover from inside the machine. Once the cover has been removed, slide the drive into position from the front of the machine and secure it in the bay using the mounting screws supplied. You will need at least four screws to properly secure the drive. The next job is to install the adapter card into a spare expansion slot on the motherboard. This card is the “go-be54  Silicon Chip tween” for the motherboard and the CD-ROM drive. More often than not, it will be a small 8-bit card but some 16-bit cards are now also starting to appear. Note that both SCSI and IDE adapter cards are available for CD-ROM drives, so make sure that you choose the correct type for your particular drive. In addition, an IDE adapter may be either a proprietary type (ie, it suits only one particular brand) or it may be a generic type, in which case it can be used with one of several different brands. To further complicate matters, some of the very latest CD-ROM drives (eg, the Sony CD-55E) can be used with an IDE hard disc drive adapter card. The drive is simply connected to a spare output connector on the card (provided one is available, that is). Of course, if you buy a complete package, then you don’t have to worry about compatibility problems. If you have a generic adapter card, you may have to change the jumper settings to suit your particular drive. The jumper settings for a Panasonic drive will be different to those for a Sony drive, for example. The literature accompanying the card will show you what jumper settings to use. This done, connect the data cable to the card and then plug it into the mother­board. Be sure to position it so that the other end of the data cable reaches the drive connector. The free end of the data cable can now be plugged into the drive, along with the power supply connection. There will usually be a spare supply cable “floating” around inside the computer. If you don’t have any left, you can obtain supply splitter cables from your local computer store. Note that the plugs and data cable connectors will be polarised, to stop you from making connections the wrong way around. In some machines, you may have difficulty gaining access to the back of the drive due to the proximity of the power supply. This problem can usually be overcome by undoing a few screws so that the front section of the case, including the drive bays, comes free. The connectors can then be plugged into the new drive and the case reassembled. Installing the software OK, that’s the mechanical side of the job done. Before using your new CD-ROM drive though, you have to install the driver software. This is supplied on a floppy disc that comes with the drive. If you didn’t get this disc, then you will have to go back to your computer store because your CD-ROM drive won’t work without it. Loading the software is straightforward, since this can be done automatically; eg, by inserting the disc, logging to the drive and typing INSTALL (or similar). By simply following the instructions on the screen, this will automatically install the correct device drivers and make the necessary alterations to your config.sys and autoexec. bat files. For the vast majority of cases, the automatic installation procedure is the recommended way to go. In some cases, however, you might want to copy the relevant driver file(s) to your hard disc and change the config.sys and autoexec.bat files yourself. If you follow this second route, be sure to create a boot­able floppy disc and backup your existing config.sys and autoex­ec.bat file before altering anything. To create a bootable floppy disc, simply insert a disc in your A: (or B:) drive and type: format A: /s. This formats the disc and copies the MSDOS.SYS and IO.SYS system files across. You can then copy the existing au­ toexec.bat and config.sys files to the disc. This disc is there as an insurance policy, in case you do something Many early CD-ROM drives used a disc caddy to load the CD while in the more recent units, the CD is loaded into a drawer in exactly the same manner as for an audio CD player. A CD-ROM can hold up to 1.2Gb of data. wrong and your computer refuses to boot up after you’ve made changes. If this happens, it’s simply a matter of booting off the floppy and copying the old config.sys and autoexec.bat files to the hard disc. The installation instructions for your CD-ROM will tell you how to modify the config.sys and autoexec. bat files. Let’s take a look at a couple of typical examples, one involving an old Sony CD-ROM drive that we installed in one of our machines and the other a more recent Panasonic drive. In both cases, IDE adapter cards were used. For the Sony drive, the device driver file was called SONY_CDU.SYS and this had to be loaded from config.sys. The line we had to add was: DEVICE = C:\SONY_CDU.SYS /D:SONY001 /B:340 /T:H This tells the computer to load in device driver SONY_CDU.SYS with the following parameters: device name as SONY001; the base address of the CD-ROM as 0340 hex; and the transfer rate as high-speed polling. This last feature determines whether your PC accesses the ROM drive via the standard data transfer mechanism or via direct memory access. This latter method is somewhat faster but relies on the ROM drive being able to go that fast for there to be any benefit. A standard ASCII text editor is used to make the changes to config.sys (eg, the DOS EDIT program). A line was then added to autoexec.bat to load MS-DOS’s MSCDEX.EXE program. The relevant line in this case was: C:\DOS\MSCDEX /D:SONY001 The important thing here is that the device name (ie, what comes after the /D:) must match the name used in the config.sys line. You can basically choose whatever name you want but they must both be the same. This is the way the PC recognises the ROM drive as part of the driver subsystem. Once these changes had been made, the relevant driver file (ie, SONY_CDU.SYS) was copied to the root directory of the C: drive. The computer was then rebooted so that the changes could take effect and give access to the CD-ROM drive On the second computer, similar changes were made to con­fig.sys and autoexec.bat. In this case, however, we had to load a driver file called CDMKE. SYS. The line added to con­fig.sys was: DEVICE=C:\CDMKE.SYS /D:PANASON while the line added to autoexec.bat was: C:\DOS\MSCDEX.EXE /D:PANASON /L:R As before, the name given to the device (ie, PANASON) is the same in both cases. The letters /L:R at the end of the au­toexec.bat line simply designates the CD-ROM as drive R:. If this instruction is left out, then DOS would simply assign the next available letter after the hard drive (eg, D:). Note that the LASTDRIVE= designation in config.sys must come after the assigned drive letter. For example, LASTDRIVE=Z will work OK with the above example, while LASTDRIVE=I will cause problems (since R comes after I). Note also that the above two examples for the Sony and Panasonic drives are given as a guide only. Each installation will be different, depending on the drive model and the type of adapter card used. Unless you know exactly what you are doing, stick with the automatic software installation procedure. Testing To test the new drive, install a CD and check that you can access the drive from the Windows File Manager or by typing R: <ENTER> at the DOS prompt. If you can access the drive OK, it should now be possible to bring up a list of files (type DIR if at the DOS prompt). If DOS returns a “drive not ready” message, it’s possible that you’ve just been a bit impatient. When you install the disc, the drive will take a few seconds to spin up to speed so wait until the green light appears before attempting to access the drive. Finally, note that not all CD-ROM drives are supplied with software that will allow you to play normal music CDs. If this facility is important, check before you buy or make sure that you can obtain the required software by SC some other means. February 1995  55