MAP                   Show memory map

EMS need at least 64 Kb. Memory above 640 Kb can be used to more than
just the usual EMS. You can allocate more pages, causing EMS to be faster.
These frames don't have to be contigues, but can be scattered anywhere
between 640 Kb and 1024 Kb. Each page takes 16 Kb and must allocated at a
16 Kb boundary.

Type:         LIMSIM MAP at the DOS prompt.

The output may look like this:

         +---------------------------------------------+
         | Hex Address  Start  Size      Usage         |
         |  0000-9FFF     0k   640k  DOS Memory        |
         |  A000-BFFF   640k   128k  Reserved          |
         |  C000-C3FF   768k    16k  ROM               |
         |  C400-CBFF   784k    32k  Unused            |
         |  CC00-CDFF   816k     8k  ROM               |
         |  CE00-DFFF   824k    72k  Unused            |
         |  E000-EFFF   896k    64k  EMS Page Frame    |
         |  F000-FFFF   960k    64k  ROM               |
         +---------------------------------------------+

Usually the largest segment is used as HIDOS. The largest unused segment here
is CE00-DFFF and can be used as HIDOS. But because HIDOS must be allocated
at 16 Kb boundary you can only use D000-DFFF by adding the following in your
CONFIG.SYS: device=limsim.exe neat hidos=D000-DFFF

Memory at C400-CBFF can be used as extra EMS pages by the following line
in your CONFIG.SYS: device=limsim.exe neat ems=C400-CBFF

By adding the two, HIDOS and EMS, You get:
                    device=limsim.exe neat hidos=D000-DFFF ems=C400-CBFF

After booting and typing: LIMSIM MAP the output may look like this:

         +---------------------------------------------+
         | Hex Address  Start  Size      Usage         |
         |  0000-9FFF     0k   640k  DOS Memory        |
         |  A000-BFFF   640k   128k  Reserved          |
         |  C000-C3FF   768k    16k  ROM               |
         |  C400-CBFF   784k    32k  Mappable EMS      |
         |  CC00-CDFF   816k     8k  ROM               |
         |  CE00-CFFF   824k     8k  Unused            |
         |  D000-DFFF   832k    64k  DOS Extension     |
         |  E000-EFFF   896k    64k  EMS Page Frame    |
         |  F000-FFFF   960k    64k  ROM               |
         +---------------------------------------------+

If You don't need either HIDOS or extra EMS pages, You can of course avoid it.
Just remeber that their can only be one HIDOS.

The installation is more complicated if your memory is scattered, and you
have to relocate ROM. Read more in BIOS.