Creating a bootable disk with CD ROM support

In order for your CD ROM drive to function in a MSDOS environment, that is when none of the Windows components or Windows drivers are loaded, you need to load a real mode CD ROM driver and a small program (MSCDEX.EXE) that initializes it and assigns it a drive letter. In summary, this is done by specifying a line in the CONFIG.SYS file that loads the driver, with a switch that assigns an "alias" to it. Next, a line in the AUTOEXEC.BAT file loads MSCDEX.EXE with the switch that references the alias defined in CONFIG.SYS for the CD ROM driver. 
Note: If all you need to do is get the CD-ROM drive to work so you can install or reinstall windows and you just don't want to deal with all this, scroll down to download a .ZIP file to be extracted to a bootable floppy disk that will allow you to install Windows 95 from the CD-ROM. The driver will work with most IDE CD-ROM drives. If you are running Windows 98, separate (and easier) instructions are provided below as well. 

Here is a typical example of loading a CD ROM driver in the CONFIG.SYS file. Note the drive and path, you must change this to the correct path and filename of your real mode CD ROM driver. Typically, it will have the file extension of .SYS as do most drivers that load in this manner. 

DEVICE=C:\CDROM\VIDE-CDD.SYS /D:IDECD001 

Note that the /D: switch is NOT to assign a drive letter, think of that switch as "Driver" and the IDECD001 is the "alias" that we are assigning to the driver. Its importance will be apparent soon. 

Here is an example of a line that loads MSCDEX.EXE in AUTOEXEC.BAT: 

C:\WINDOWS\COMMAND\MSCDEX.EXE /D:IDECD001 

Note the usage of the /D: switch again. The alias (in this case IDECD001 must be identical to the one specified in the CONFIG.SYS file. When you go to edit these configuration files, look at your AUTOEXEC.BAT file and you may see that the MSCDEX line is already there, but is prefaced with "REM - BY WINDOWS SETUP". This is because Windows 9x setup comments out that line because real mode drivers should not load with Windows, which has protected mode CD ROM drivers of its own. In many cases you simply need to remove the REM - BY WINDOWS SETUP from the command and reboot to command prompt only, and you will have DOS CD ROM support. Be sure to add REM in front of the line before you boot back into Windows 9x, as MSCDEX.EXE should not load with Windows 9x. 

If you are lucky, or if your CD ROM uses proprietary drivers, you may have a driver disk that came with your computer or CD ROM drive. In that case all you will have to do is put the disk in the drive and type "setup" or "install", (whichever the case may be, look for setup.exe or install.bat or install.exe etc. on the disk) and the setup will take care of this mess for you. 

Now, why do you want CD ROM support in DOS? If you need it to install windows, it would be best to set this up on a boot disk. If you want CD ROM support because you want to play games, then additional commands/devices will be required in the configuration files and it would be probably easiest to set this up on the hard drive, (though you can use a boot disk for games too). I will provide some information for both, so scroll down for what is appropriate for you. 

If You Need This To Install/Re-install Windows 95

Installing Windows 95 requires a clean startup. We want as few programs or devices using conventional memory as possible, and we do not want any memory manager programs like EMM386.EXE loading. All we really want is HIMEM.SYS (to enable extended memory; memory above the 640K conventional memory), and MSCDEX.EXE and our CD ROM driver. It is a good idea to use a boot disk, preferable a Windows 95 Startup Disk. To make a Windows 95 startup disk go to Add/Remove Programs in Control Panel and click the Startup Disk tab and create the disk. Whatever you choose for a boot disk, you will have to create (if not already present) an AUTOEXEC.BAT and CONFIG.SYS file and edit them to include lines for CD ROM support. You can use Notepad for this or the MSDOS Editor. 
A Typical CONFIG.SYS file, for a boot disk to install Windows 95: 

DEVICE=A:\HIMEM.SYS
DEVICE=A:\VIDE-CDD.SYS /D:IDECD001 

A Typical AUTOEXEC.BAT file, for a boot disk to install Windows 95: 

@ECHO OFF
A:\MSCDEX.EXE /D:IDECD001 

If you do not have a real mode CD ROM driver, or are not inclined to edit these configurations yourself, I have made a .ZIP file that you can unzip to a bootable disk and then if you boot with the disk, you will have CD ROM support. I encourage you to use a Win95 Startup Disk, but if this is unavailable any bootable disk from your Windows 9x operating system will do. The AUTOEXEC.BAT file that will be on your boot disk (after unzipping the file bootdisk.zip to your bootable disk) has a batch script that will look for and attempt to copy HIMEM.SYS from your Windows directory to the boot disk. You will be prompted if this is the case. 

After downloading this file, read the README.TXT file for complete instructions. Please note that while I have done my best here, I cannot be held responsible for whether or not this works for you, or for damages that may be incurred from its incorrect use. Please note that this will only work for IDE CD ROM drives, and NOT for SCSI drives. If your drive is SCSI or requires proprietary drivers please contact the manufacturer (perhaps they have a website?) for the appropriate files (or see if you have a disk somewhere). 

You can download bootdisk.zip (22 Kb) at http://www.pcnineoneone.com/dloads/bootdisk.zip

If You Are Running Windows 98

Thankfully, the Windows 98 Startup disk already has CD ROM support for IDE and SCSI CD ROM drives. Create a Windows 98 Startup Disk by double clicking Add/Remove Programs in Control Panel and clicking the Startup Disk tab and create the disk. Boot with the disk and select the option to enable CD ROM support. Test your disk to make sure you can access the CD ROM drive before you do anything drastic like formatting the drive. (change to your CD ROM drive and make sure you can list directories and maybe open a readme file and if all that checks out you are safe.) 

If You Need CD ROM Support for Games

If you want to use the CD ROM drive in DOS because you want to play games, or for any other reason than installing windows, it would be best to set this up on the hard drive. You can rename your old AUTOEXEC.BAT and CONFIG.SYS files to AUTOEXEC.BAK and CONFIG.BAK and create new ones for when you want to boot to DOS command prompt only. You can then rename your old ones back before you boot into Windows again. For this usage, the configuration files will contain more commands than the example above for installing windows. In the following examples it is important to note that you will have to edit the lines to suit your own system. I have no way of knowing what hardware you have and where you keep your driver files. As for Sound Card drivers in DOS you pretty much need to have a driver disk (or a downloaded driver package) with a setup program that will install the driver files and edit your configuration files for you, unless you know the hardware settings. 
Here is a typical CONFIG.SYS file: 

DEVICE=C:\WINDOWS\HIMEM.SYS
DEVICE=C:\WINDOWS\EMM386.EXE NOEMS
DOS=HIGH,UMB
FILES=60
BUFFERS=30
STACKS=9,256
LASTDRIVE=Z
DEVICEHIGH=C:\CD ROM\VIDE-CDD.SYS /D:IDECD001 

Here is a typical AUTOEXEC.BAT file: 

@ECHO OFF
SET SOUND=C:\SB16
SET BLASTER=A220 I10 D0 H5 P330 T6
SET MIDI=SYNTH:1 MAP:E
C:\SB16\DIAGNOSE /S
C:\SB16\MIXERSET /P /Q
SET TEMP=C:\TEMP
PROMPT $p$g
LOADHIGH C:\MOUSE\MOUSE.EXE
LOADHIGH C:\CD ROM\MSCDEX.EXE /D:IDECD001

Note the usage of the DEVICEHIGH command in CONFIG.SYS and the LOADHIGH command (can be abbreviated to LH) in the AUTOEXEC.BAT file. Because we loaded EMM386.EXE (a memory manager) we can load some devices in the high memory area to free up more conventional memory for programs. 

If you do not have real mode CD ROM drivers, either use the one from your WIN98 startup disk (note which one is loading as you boot with it) or download the bootdisk.zip file I made and use that one. 


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