Configuration

TIP: To edit files, DOS has a notepad-type of editor.
The command to start the editor is: edit
You can specify the file to edit by adding a space and the complete filename.

The config.sys file is the 1st file read by the operating system after the power on system test (POST) is completed. It is the file that loads your memory managers, files & buffers space, cdrom driver, mouse driver, and all the other device drivers your system requires to operate.

Each line in the file loads 1 device. Here's a typical config.sys file:

DEVICE=C:\WINDOWS\HIMEM.SYS
DOS=HIGH,UMB
DEVICE=C:\WINDOWS\EMM386.EXE NOEMS I=B000-B7FF D=64
FILESHIGH=50
BUFFERSHIGH=15
SHELL=C:\COMMAND.COM C:\ /E:1024
STACKSHIGH=0,0
FCBSHIGH=1
DEVICEHIGH=C:\WINDOWS\MOUSE.SYS
REM - Attention! This line is reserved for a CD-ROM driver.
;DEVICEHIGH=C:\CDMKE.SYS /D:MSCD0001 /P:630
DEVICEHIGH=C:\CDMKE.SYS /D:MSCD0001 /P:340

Let's do a little disecting...

• The first line loads your high memory access device. Windows will not run if this line is missing or damaged.
• The second line loads the DOS operating system into high memory and uses the UMB (the first upper memory block above the first megabit of memory).
• The third line loads your expanded memory manager. If you are only running WINDOWS programs, you can eliminate this line by placing a semicolon in front of it. This will free memory for use by other devices!
  This line can contain many optional parameters.
  • NOEMS - tells the manager not to set aside any memory as expanded. If you need expanded memory (for a program like Lotus1-2-3) you would see the parameter RAM and a number, instead of NOEMS, to allocate expanded memory.
  • The next parameter (I=B000-B7FF) tells the manager to Include the memory area at hex address B000 to B7FF as available memory. The alternate parameter to Include is eXclude. It acts in exactly the opposite manner. This can be used to prevent the manager from using the upper memory areas required by most high resolution video cards. The most common form is X=C000-CFFF.
  • The final parameter is used to set aside a number of Data buffers for use by the expanded memory manager. This is optional, but when used is normally 32 or 64.
• The next four lines set aside space for open files, buffer area, processing stack, and file control bits. Notice that the command used is DEVICEHIGH. This requests the device be loaded into high memory. If no space is available, the device will automatically be loaded into conventional memory.
  • FILES, sets the number of open files allowed at any one time. The value should be between 50-99. If you work with large databases, set it at 99.
  • The buffers setting can affect the hard disk transfer speed depending on the type of information being retrieved. A good setting is between 10-20. The lower the number, the better the response from the hard disk. Numbers lower than 10 can slowdown the hard disk operation.
  • The STACKS and FCBS are set by the system and should not be changed!
• The next line loads the mouse driver. This is only required to enable the mouse outside of the Windows operating environment.
• The next line is a comment (REMark) line. You can use these to leave notes to yourself, or others, about the information contained in the file.
• The second last line is started with a semicolon. This tells the operating system to ignore this entire line. It is in the file because this system used two different driver cards for cdroms, and rather than delete it and then try to remember it when it was needed again, it has simply been told to be ignored.
• The last line loads a device driver for the cdrom. It sets the name of the device (/D:MSCD0001), and the address in hex /P:340.

TIP: Here's a quick overview to peak your config.sys:

• Use the NOEMS parameter in the EMM386.SYS line to make more RAM available.
• Set FILES to 99.
• Set BUFFERS between 10-20.
• Use a semicolon to ignore a line without deleting it. This can be used to try to free up memory for programs requiring more conventional memory. If you have problems, simply remove the semicolon, save the file, and re-boot.
• Use REM to start a comment line. It can remind you what the line is doing or why it was there.

Remember: You have to reboot your computer to see any changes made to the configuration.

TIP: To bypass your startup files (go to a DOS prompt), press F5 when you see "Loading MS-DOS . . ." (Right after your system beeps). For Windows 95, press the F8 key to bring up the start menu.

This does not load any devices, so your cdrom, mouse, Windows, and many other things will not work. But you may be able to run a non-windows program that would not work before because there was not enough available memory.