Memory Extenders (EMS and XMS)
The following settings affect the behavior of the EMS and XMS memory extenders,
if used in the VDM. For an explanation about the implementation of EMS
and XMS support in VDMs, see Memory
Extender Support.
MEM_EXCLUDE_REGIONS
Function:
This setting is used to specify
address ranges which should be protected from use by EMS/XMS and direct
access by applications. This setting is intended for experienced users
who understand the hardware.
Advantages:
This setting restricts the use of EMS/XMS on
certain ranges in the region between RMSIZE and 1MB. It also protects these
ranges from being touched by user applications by portraying ROM there.
Drawbacks:
Some
hardware adapters stop functioning if their addresses are touched in random
fashion. If these ranges are defined excessively, they will adversely impact
the function and performance of EMS and XMS services.
Default:
By default, this setting is void. Each address
is specified in hex and if there is no range specified, the length taken
is a page (4KB).
Settable:
Examples:
MEM_INCLUDE_REGIONS
Function:
Specify regions which should be
made available to EMS/XMS. This setting is used to specify some address
ranges between RMSIZE and 1MB for use by EMS and XMS.
Advantages:
If there is a hardware adapter in this range
which the user knows is not going to be used by a particular VDM session,
then the address range used by this adapter should be made available to
EMS and XMS. This will improve the performance of EMS and XMS services.
Only advanced users who know the addresses used by a card should use
this setting.
Default:
By
default, this setting is void.
Settable:
Examples:
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