INT 15 - DESQview v2.23+ - "GETCOMMON" - ALLOCATE "COMMON" MEMORY
        AX = DE19h
        BX = number of bytes to allocate
Return: AX = 0000h successful
                ES:DI -> allocated block
             nonzero insufficient memory
Note:   this API call may be made from within a hardware interrupt handler
SeeAlso: AX=DE15h,AX=DE1Ah