Compatibility: EMS 4.0+
Expects: AH    55H
AL    subfn: 00H=Use page numbers in prMapInfo->wFrameLoc
01H=Use segment addresses in prMapInfo->wFrameLoc
DS:SI address of an EmsMapAndJmpRec (see below)
DX    EMM Handle (as obtained via INT 67H 4300H)
                                                                  
Returns: (none)
                                                                  
Info: This lets you swap some pages of executable code into memory,
then execute that code.

DS:SI points to a structure that identifies which pages to map and
where to jump.  If is formatted as:

EmsMapAndJmpRec
Offset Size Contents
                                                          
+0      4  pCodeAddr  FAR address to JMP
+4      1  bPgCnt     number of pages to map
+5      4  prMapInfo  FAR addr of an EmsMapInfoRec
9             size of this structure

Depending upon AL, the wFrameLoc fields of the EmsMapInfoRec will
contain either page numbers (usually 0-3) or segment address (for
instance, d000H, d400H, etc).

Notes: See INT 67H 50xxH (map multiple pages) for related info.

This fn does not provide a mechanism to return control to the
caller.  Use INT 67H 56xxH (map and call) to CALL rather than
JMP.

- -

INT 67H 55xxH: Alter Page Map and JMP