home *** CD-ROM | disk | FTP | other *** search
-
- ┌───────────────────────────────────────────┐
- │ Maximizing The Amount of Low DOS Memory │
- └───────────────────────────────────────────┘
-
- For an application program to take advantage of the maximum amount of
- additional low DOS memory, it must reside in Memory Commander's
- application database. Consult Memory Commander's manual on testing
- and adding programs to the application database. Once the
- information is stored in this database, Memory Commander will
- automatically set the best mode, on-the-fly, whenever the program is
- run.
-
-
- Actions which can increase the amount of low DOS memory:
-
- High Loading Turn off or reduce the size of the High DOS/TSR/Driver
- area. To alter the size of the High DOS/TSR/Driver area, from
- the Main menu select Advanced Configuration, and then High
- DOS/TSR Driver memory allocation. Memory that is allocated to
- the high DOS/TSR/Driver area directly reduces the memory
- available to maximize the amount of low DOS.
-
- EMS Page Frame EMS memory normally requires 64K of memory which
- cannot be used to increase DOS. If none of your applications use
- EMS, set EMS off. For Windows, EMS must be on, but the page
- frame can be turned off to save 64K, if none of your other
- applications uses EMS. EMS options can be changed from Memory
- Commander's Advanced Configuration, Features and Options menu.
-
- MS/PC DOS Version Different versions of DOS use different amounts of
- memory. We recommend using MS/PC-DOS 5.0 to get the most
- possible available low memory. The following chart shows the
- maximums possible.
-
- Maximum memory AVAILABLE to a program (1K = 1024 bytes)
-
- Version Mode A Mode E (VGA Text)
- ───────────── ────────── ─────────────────
- MS-DOS 3.3 575K 855K
- MS-DOS 4.0 565K 845K
- MS-DOS 5.0 621K 901K
-
- Adapter Cards Memory Commander automatically moves the video BIOS and
- hard disk BIOS to maximize low memory. Other adapter cards such
- as network cards, scanner cards, and others, can not be moved.
- They create an immovable boundary. If these cards are present,
- the cards may have an option to position the on-card ROM/RAM
- higher in memory. A higher position allows more low memory to
- be allocated.
-
- DOS CONFIG.SYS Options The DOS options selected within the
- CONFIG.SYS file can usually gain additional available low memory.
- Select the menu option for "System Recommendations - CONFIG.SYS".
-
-
- Special Cases which limit the amount of low DOS memory:
-
- Immovable BIOS ROM A few hard disk BIOSs are not relocatable. This
- means Memory Commander cannot move the BIOS ROM position into a
- higher position in memory to expand DOS further. Usually these
- cards have a ROM which can only reside at one location. You may
- wish to contact the card vendor to see if a later version is
- available which allows moving the ROM to another position in
- memory.
-
- Extended BIOS data area A few computers take away 1 to 4K bytes of
- data from the top of DOS for use as the extended BIOS data area
- or for other uses. When running CHKDSK, a normal system with at
- least 640K of RAM will show 655,360 or more bytes total. If this
- number is less by 1024 to 4096 bytes, some BIOS or program has
- removed this memory from use.
-
- Memory Commander can normally recover this space, or in some
- cases relocate it to another area. If this can not be moved or
- removed, DOS low memory cannot be expanded. Some of these
- systems provide an option to turn off the use of this area using
- the computer's setup program. If booting from a floppy causes
- the system to see the full 655,360 bytes, a virus may have
- infected the boot sector of the hard disk, and should be removed.
-
-