3100  (250-1632)         System Memory Map             Faxback Doc. # 5505

Your system can accommodate the following types of memory:

Base RAM (conventional memory) - Memory below 640KB, which can be used by
MS-DOS and all MS-DOS applications without requiring drivers.

Shadow RAM (upper memory area) - Memory from 640KB to 1024KB (1MB), which
is used by the system BIOS, video BIOS, and other BIOS extensions.

Extended memory:  Continuous memory above 1MB, which can be addressed
                  directly by i486 microprocessors.  Extended memory is
                  often used for software disk caches, RAM disks, and
                  software print spoolers.  Extended memory can be
                  directly used by many Windows and MS-DOS applications
                  when you use the appropriate memory-related operating
                  system features.  Refer to your operating system
                  documentation to learn more about using extended memory.

Expanded memory:  If you run programs that are designed to use expanded
                  memory, you can use MS-DOS commands to enable your
                  system to use expanded memory.  Refer to your software
                  documentation for more information on using expanded
                  memory.

Operating systems such as OS/2 or UNIX can also use extended memory.
Refer to the operating system documentation for details on how memory can
be used.

The following diagram illustrates the arrangement of memory in your
computer:

      67,108KB ┌───────────────────────┬───────────────────────┐
   or 52,428KB │ 1000000-3FFFFFF       │ Main Logic Board      │
               │ or 1000000-31FFFFF    │ System RAM            │
      16,384KB ├───────────────────────┼───────────────────────┤
               │ 100000-FFFFFF         │ Main logic Board      │
               │                       │ System DRAM or ISA    │
               │                       │ Bus                   │
       1,024KB ├───────────────────────┼───────────────────────┤
               │ OF8000-0FFFFF         │ Shadow DRAM           │
               │                       │ Containing AT         │
               │                       │ System BIOS           │
         992KB ├───────────────────────┼───────────────────────┤
               │ 0F0000-0F7FFF         │ Shadow DRAM           │
               │                       │ Containing            │
               │                       │ System Setup          │
               │                       │ Utility               │
         960KB ├───────────────────────┼───────────────────────┤
               │0E0000-0EFFFF          │ Unused                │
               │                       │ Not Available on ISA  │
               │                       │ Bus                   │
         896KB ├───────────────────────┼───────────────────────┤
               │C8000-0DFFFF           │ Shadow DRAM or        │
               │                       │ ISA Bus               │
         832KB ├───────────────────────┼───────────────────────┤
               │C0000-C7FFF            │ Video BIOS            │
         768KB ├───────────────────────┼───────────────────────┤
               │0A0000-0BFFFF          │ Video DRAM            │
         640KB ├───────────────────────┼───────────────────────┤
               │00000-09FFFF           │ System DRAM           │
           0KB └───────────────────────┴───────────────────────┘

(smc 01/04/94)