3.1. Memory requirements and memory managers
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 Although the Blinker 4.x DOS extender defaults to looking for a DPMI host
 first for maximum compatibility, a VCPI or XMS host may provide more memory
 to a DOS extended application in tight memory situations. As a result, DOS
 extended programs may run better on smaller machines when only HIMEM.SYS is
 installed.

 In particular QDPMI allocates around 70kb of conventional memory when a
 program starts up, and this cannot be swapped out by the SWPRUNCMD()
 functions. As a result, QDPMI support is automatically disabled when the
 swapper is linked into a program. This default setting can be overidden with
 the BLINKER HOST QDPMI command or the /HQ environment setting.

 Note: When creating a menu program which then swaps out to a DOS extended
 program it is more memory efficient to make the menu program a real mode
 program and use the SWPRUNCMD() than to also make the menu program a DOS
 extended program.