Q. how to Configruing with Config.sys and Autoexec.bat files

Configruing with Config.sys and Autoexec.bat files

CONFIG.SYS is an ASCII file that contains instructions to DOS for making best of your system's recources.

The AUTOEXEC.BAT file is an ASCII file that contains a series of DOS line commands which will be invoked, in sequence automatically at startup time. Although is can contain any command that can be validly invoked its purpose is to invoke additional configuration commands and start up programs that you would other wise invoke yourself each time you started your computer.

Multiple configuration

There is feature that allows you to write CONFIG.SYS so that you can choose among multiple configurations at startup time. For example consider RAM disk. A RAM disk is special area of random-access memory that appears to the operating system to be another disk drive. Its advantage is that it is faster than physical disk drive or more convenient for storing temporary files. RAM disks are initialized using CONFIG.SYS.

There may be times when you want a RAM disk and other times when you would prefer not to use up valuable RAM that might be better used by one or more of your applications. You would be required to edit the CONFIG.SYS file and restart you computer and choose whether or not to include the RAM disk. Before attempting to rewrite you CONFIG.SYS file to support multiple configurations, you must be familiar with standard CONFIG.SYS syntax and use driver files. Multiple configuration CONFIG.SYS file utilizes this fundamental syntax plus some additional elements; menu blocks, configuration blocks, directives, and common block.

The general structure of a multiple-configuration CONFIG.SYS file is all follow:

(a) A sequence of required commands if any that must be invoked first, regardless of which option is to be selected.

(b) An initial menu block, always named {menu}, containing up to nine configuration choices for use.

(c) Any number of configuration blocks, that contain commands referenced in optional configuration blocks.

(d) The series of optional configuration blocks, containing the commands required for each optional selection from the menu.

(e) A final common configuration block, always named {common} which is the last configuration block in the file. This block contains configuration commands that are always invoked, regardless of which option is chosen, but must follow the optional configuration blocks in the file.

In addition, a multiple-configuration CONFIG.SYS file may contain submenus. A submenu is another configuration block with a unique block neme that contains additional menu commands. It is referenced like any other configuration block but functions like additional, nested menu, use submenus if you require more that nine optional configuration or if you feel that submenus organize your possible choices more logically that single menu.

The program Listing shown below is a simple multiple-configuration CONFIG.SYS file that demonstrates a typical structure. The elements in this file are explained more fully in the following paragraphs.

Rem ** these commands are used by all options:
DEVICE=C:\SW\COMMAND\HIMEM.SYS

(note:- instead of command if you are running DOS (Disk Operating System) you can use \DOS)
DOS=HIGH
Rem ** this is the configuration menu:
[menu]
MENUCOLOR=15,1
MENUITEM=ramsisk1, RAM disk (1024mb)
MENUDEFAULT= noramdisk, 15
Rem ** this is the configuration block for initialization
DEVICE=WIN.EXE RAM HIGHSCAN