INT 21 - European MS-DOS 4.0 - "CREATMEM" - CREATE A SHARED MEMORY AREA
	AX = 8400h
	BX = size in bytes (0000h = 65536)
	CX = flags
	    bit 6: zero-initialize segment
	DS:DX -> ASCIZA NUL-terminated ASCII string.	The ASCIZ string "ABC" consists of the four bytes 41h, 42h, 43h, and 00h.  Unless otherwise specified, maximum lengths given in the interrupt list do not include the terminating NUL. name (must begin with "\SHAREMEM\")
Return: CF clear if successful
	    AX = segment address of shared memory global object
	CF set on error
	    AX = error code (06h,08h) (see #01680 at AH=59h/BX=0000h)
Desc:	create an area of memory which may be accessed by multiple processes
Notes:	shared memory objects are created as special files (thus the
	  restriction on the name)
	on successful creation, the reference count is set to 1
SeeAlso: AX=8401h,AX=8402h,INT 15/AX=DE19h