Although all versions of CD-ROM extensions work basically the same way, installation procedures may vary slightly from one supplier to another. Many versions contain a program that will automatically install the software for you, after you have answered a few questions about the type of equipment that you plan to use. Be sure to follow the instructions for installing CD-ROM Extensions that are provided with the software.

The first step, if you are installing extensions without the aid of an automatic set-up program, is usually installing the device driver program and MSCDEX. EXE on your bootable disk. For computers containing a hard drive, this usually means drive C. The name of the device driver program varies from one version of extensions to another; one common practice of software developers is to name it after the brand of CD-ROM drive that it supports, e. g. , HITACHI. SYS. The device driver program and MSCDEX are frequently set up in separate subdirectories; however, this practice is not universal.

The next step is to add a line to the CONFIG. SYS file to identify the device driver program. This line typically looks something like this:

DEVICE=\path\driver name/D:\driver alias/N:#

For example: device=\dev\HITACHI. SYS/D:MSCD001/N:1
The driver name (e. g. , HITACHI. SYS) and the driver alias should be provided by the set-up program or in the instructions that accompany the floppy disk containing the extensions software. The symbol # at the end of the line should be replaced with the number of CD-ROM drives (up to 4) that will be hooked up to the microcomputer.

The third step is to add a line to the AUTOEXEC. BAT file for running MSCDEX. EXE and assigning a letter to your CD-ROM drive. Depending on your system configuration you may opt to set up one or more batch files to accomplish the same purpose. If you add a line to the AUTOEXEC. BAT file, it will probably look something like this:

\path\MSCDEX. EXE/D:driver alias/M:8/L:L

For example: \BIN\MSCDEX. EXE/D:MSCD001/M:12/L:L

The driver alias, which is really the name that your system will use to identify the device driver, should be the same one that is named in your CONFIG. SYS file.

The number following M: is the number of memory buffers allocated (usually 8, but sometimes more). The last letter, following the L:; designates the letter assigned to the CD-ROM drive.

Though the final step is simple, it's also easy to overlook. You must reboot the system in order to activate the changes that you've made to your CONFIG. SYS and AUTOEXEC. BAT.

Once properly installed, the device behaves much like a read-only floppy diskette drive, and simple MS-DOS commands such as DIR are possible. If the computer reports that the CD-ROM is not High Sierra, you must first upgrade your Microsoft CD-ROM Extensions software to version 2. 0 or later.

This CD-ROM contains data retrieval software. This software was developed and tested on a COMPAQ Deskpro 286 with 640K RAM operating under MS-DOS 3.31. The software was compiled with Clipper (Summer '87). There are no special display requirements. Please note that the retrieval software will only run on IBM-compatibles operating under MS-DOS.

To execute, type GO at the DOS prompt and ENTER.

Example: L:\>go

The data on the CD-ROM are in dBase III+TM format. Data in dBase III+ format are recognized by many software packages including dBaseIVTM, FoxbaseTM, ClipperTM, SupercalcVTM, Quattro ProTM, and VP-PlannerTM.

Users of other types of systems, such as the Apple Macintosh, have access to the files through support for ISO 9660 CD-ROMs.