Lab 2.3: Optimizing DOS Memory


Logical memory is the way physical memory is seen by the operating system. The MS-DOS memory map shows the first 640KB of RAM as the user (conventional) area and the rest of the first megabyte of RAM as reserved for the computer’s needs. The user area is the problem area for DOS users because DOS uses some of the conventional memory as you load applications or add new hardware drivers. As conventional memory is used, programs that have been running may report insufficient memory when they are next executed. The usual solution to this problem is to optimize memory.

You can optimize DOS memory usage manually by modifying the AUTOEXEC.BAT and CONFIG.SYS files or using the MEMMAKER utility. DOS experts can do a better job of optimizing memory than the MEMMAKER utility, but the number of DOS experts is in decline. For most situations, running MEMMAKER yields satisfactory results.

Upon completion of this lab, you will be able to:

  • Determine memory usage in a DOS system

  • Optimize memory in a DOS system

Set Up

For this lab, you will need a working computer with DOS 6.x installed.

Exercises

In this lab, you will examine DOS memory utilization. You will also free up additional conventional memory by optimizing DOS memory with the MEMMAKER utility.

Examining DOS Memory Usage

To examine DOS memory usage,

  1. Boot the computer to drive C:.

  2. Run the MEM utility to display the current memory utilization:

    C:\>MEM 

    Record the memory information from the MEM utility in Table 2.1.

    Table 2.1: Memory Information

    Memory Type

    Total

    Used

    Free

    Conventional

    _______KB

    _______KB

    ___________KB

    Upper

    _______KB

    _______KB

    ___________KB

    Reserved

    _______KB

    _______KB

    ___________KB

    Extended (XMS)

    _______KB

    _______KB

    ___________KB

    Total memory

    _______KB

    _______KB

    ___________KB

    Total under 1MB

    _______KB

    _______KB

    ___________KB

    Largest executable-program size

    _______KB

    Largest free upper-memory block

    _______KB

Optimizing DOS System Memory with the MEMMAKER Utility

To optimize DOS system memory with the MEMMAKER utility,

  1. Enter the following command to optimize the DOS memory with the MEMMAKER utility:

    C:\>MEMMAKER 

    Accept the default conditions as the program runs.

  2. If the computer fails during the MEMMAKER utility, warm-boot the computer, run MEMMAKER again, and choose Try Again with Conservative Settings.

  3. If the computer is unable to boot after MEMMAKER runs, boot to a DOS utility disk and enter the following command to undo the optimization:

    C:\>MEMMAKER /UNDO 
  4. After MEMMAKER has finished optimizing the system’s memory and reboots the computer, run the MEM utility again:

    C:\>MEM 

    Record the memory information from the MEM utility in Table 2.2.

    Table 2.2: After-Optimization Memory Information

    Memory Type

    Total

    Used

    Free

    Conventional

    ________KB

    __________KB

    __________KB

    Upper

    ________KB

    __________KB

    __________KB

    Reserved

    ________KB

    __________KB

    __________KB

    Extended (XMS)

    ________KB

    __________KB

    __________KB

    Total memory

    ________KB

    __________KB

    __________KB

    Total under 1MB

    ________KB

    __________KB

    __________KB

    Largest executable-program size

    ________KB

    Largest free upper-memory block

    ________KB

  5. Compare the conventional memory usage listed in Table 2.1 with that listed in Table 2.2. If the Free amounts in Table 2.2 are greater than those in Table 2.1, the optimization was successful.




A+ Complete Lab Manual
A+ Complete Lab Manual
ISBN: 782128041
EAN: N/A
Year: 2003
Pages: 160

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