Category: memory management
Flags: available only in protected mode
INT 2C - Cloaking - ALLOCATE GDT SELECTOR

	AX = 0000h
	EBX = base address
	CL = access mode byte
	CH = extended access mode byte (omit limit field)
	EDX = segment limit
Return: CF clear if successful
	    AX = selector
	CF set on error
	    AX = error code (see #02556)
Notes:	this INT 2C interface is used by Netroom's DPMI.EXE v3.00
	to access extended memory, set the base address to the desired
	  physical address plus 400000h (4M)
	this function was first introduced with RM386 (RAM-MAN/386) v6.00, the
	  memory manager included in Helix Software's Netroom
SeeAlso: AX=0001h,AX=0002h,AX=0003h,AX=0004h,AX=0005h,INT 31/AH=57h,#00501