INT 21 - FlashTek X-32VM - RESERVE BLOCK OF MEMORY FOR 32-BIT STACK AX = 350Dh EBX = current ESP value ECX = size of block in bytes DS = default DS Return: CF clear if successful EBX = new value for ESP EDX = suggested new limit for SS CF set on error Note: this function should only be called once during initialization SeeAlso: AX=350Bh,AX=350Ch