What is a boot disk and why do I need one?
What is it?A boot disk is a floppy disk that contains configuration files to manage memory and drivers. Rather than loading Windows and its memory management system when the computer boots up, you will be loading DOS and configuring its memory settings with a boot disk.
Boot disks are to be used on computers using the DOS, Windows, 3.1, Windows 95 and Windows 98 operating systems only. Windows ME, Windows 2000 and Windows XP cannot work with a DOS boot disk, therefore a DOS game may not run under these operating systems.
Windows uses a different memory management system than DOS. It also uses different drivers for the mouse, CD-ROM drive and sound card. This is why a DOS game may not run in Windows. This is also why a boot disk is needed to start the computer in DOS mode and set up the DOS specific drivers.
DOS also has a limit of 640kb of conventional memory. This is the maximum space allowed to load drivers and the game executable. You can type MEM to display how much free conventional memory you have; this is also called the "largest executable program size." If the game’s executable file is larger than the amount of free conventional memory, the game will not run. A boot disk can manage the conventional memory size so that the game may run.
It is also not recommended to modify the configuration files on the hard drive. This could prevent some programs or the operating system from working correctly. This is why a bootable floppy disk should be used. If anything does happen to go wrong, you can just eject the floppy disk, and the computer should start up normally.
How to create a DOS boot disk.
Step by step instructions.It is recommended that you read and understand the above section on what a boot disk is and why you may need one if you have not already done so. If you run into any trouble making a boot disk, you may also want to read the sections on Memory Management and DOS Error Messages. Remember this is not for Windows XP/2000 machines.
- Restart the computer in MS-DOS mode. To do this, go to Start, Shutdown and select "Restart in MS-DOS mode."
- Find a 3.5" floppy and insert it into the floppy disk drive.
- Type: FORMAT A: /S
This will erase the floppy disk and make it bootable. - Type A:
This will put you at the A: Drive so you can begin making your boot disk. - Type: EDIT CONFIG.SYS to create a file that configures the memory in DOS and loads some drivers.
Type the following lines:
DEVICE=C:\WINDOWS\HIMEM.SYS
DOS=HIGH, UMB
DEVICE=C:\WINDOWS\EMM386.EXE RAM 3072 I=B700-B7FF
FILES=30
BUFFERS=30
DEVICEHIGH=[the location of your CD-ROM Driver] /D:MSCD001
NOTE: The correct value of Files and Buffers can be found with the reference card or install guide that came with the game. EMM386.EXE may conflict with some games that have a built in memory manager such as DOS4/G or as stated otherwise in the reference card or install guilde. A conflict will cause errors or the game may freeze while loading. EMM386.EXE is required to be loaded for most PCI based sound cards. If the game has a built in memory manager and the sound card requires EMM386.EXE to be loaded, the game will not be able to run with sound. - Press ALT-F to access the File menu at the top. Select Exit and save when prompted to.
- Type EDIT AUTOEXEC.BAT to create a file that sets up the DOS environment and loads some
drivers. Type the following lines:
PATH=C:\WINDOWS; C:\WINDOWS\COMMAND
LH C:\WINDOWS\MSCDEX.EXE /D:MSCD001
LH [the location of your mouse driver]
SET BLASTER=A220 I5 D1 T4
LH [sound card lines here]
NOTE: The "SET BLASTER" values may be different, depending on your sound card. The sound card drivers are different for each type of sound card. It is recommended that you check with your sound card manufactrer and documentation to obtain and load the sound card drivers in DOS. Be aware that some sound cards may require that you copy a file to the boot disk. - Press ALT-F to access the File menu at the top. Select Exit and save when prompted to.
- Leaving the disk in the floppy drive, restart the computer. When the computer reboots, the configuration files that were just made should load. Make sure to watch for any errors.
- If the game is not yet installed, install it now. Change to the drive letter of your CD-ROM drive. (Usually by typing D:) Make sure the disc is inserted into the drive run the installation program. Typing INSTALL will work in many cases. (Refer to the install guide on the correct install command.)
- Install the game and choose your sound card. Soundblaster Compatible will usually work. You will also need to select the resources that the sound card uses such as IRQ, I/O Port and DMA Channel.
- Type CD\ [game directory] and then type the game executable to launch the game.
- When you want to return to Windows, exit out of the game, eject the disk and restart the computer.