INT 15 - SYSTEM - later PS/2s - RETURN MEMORY-MAP INFORMATION
        AH = C7h
        DS:SI -> user supplied memory map table (see below)
Note:   call AH=C0h and examine bit 4 of feature byte 2 to check if this
          function is supported
Return: CF set on error, clear if successful
SeeAlso: AH=C0h,AH=C9h,AH=D1h

Format of memory-map table structure:
Offset  Size    Description
 00h    WORD    length of table (excluding this word)
 02h    DWORD   local memory between 1M and 16M, in 1K blocks
 06h    DWORD   local memory between 16M and 4G, in 1K blocks
 0Ah    DWORD   system memory between 1M and 16M, in 1K blocks
 0Eh    DWORD   system memory between 16M and 4G, in 1K blocks
 12h    DWORD   cacheable memory between 1M and 16M, in 1K blocks
 16h    DWORD   cacheable memory between 16M and 4G, in 1K blocks
 1Ah    DWORD   1K blocks before start of non-system memory between 1M and 16M
 1Eh    DWORD   1K blocks before start of non-system memory between 16M and 4G
 22h  2 DWORDs  reserved

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