)
Call the Netroom RM386 v6.00 "Create new UMB entry" function with:
	AH = 83h
	BX = segment of high-memory block
	DX = first page of start of block
	CX = number of consecutive pages in block
	DI = start of UMB in block
Return: AX = 0001h (success)
	DI = segment of first high-DOS block
Note:	the new UMB is not linked into the high-memory chain
SeeAlso: #02766,#02784,#02786