INT 94 u - Media Vision PCM.COM - GET/SET INTERNAL DMA BUFFER
        SI = 8015h
        ES:BX -> DMA info structure (see below)
Return: ???

Format of DMA info structure:
Offset  Size    Description
 00h    DWORD   -> DMA buffer (offset FFFFh = return current buffer info)
 04h    WORD    DMA buffer size
 06h    WORD    divisions

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