INT 65 - Ad Lib SOUND.COM - INTERFACE
        SI = function number (see also entries below)
            0000h Init
            0002h RelTimeStart
            0003h SetState
            0004h GetState
            0005h Flush
            0006h SetMode
            0007h GetMode
            0008h SetRelVolume
            0009h SetTempo
            000Ah SetTranspose
            000Bh GetTranspose
            000Ch SetActVoice
            000Dh GetActVoice
            000Eh PlayNoteDel
            000Fh PlayNote
            0010h SetTimbre
            0011h SetPitch
            0012h SetTickBeat
            0013h NoteOn
            0014h NoteOff
            0015h Timbre
            0016h SetPitchBend
            0017h WaveForm
        ES:BX -> arguments
Note:   the installation check consists of checking for the signature block
          immediately preceding the interrupt handler (see below)

Format of signature block:
Offset  Size    Description
 00h    WORD    version number
 02h 19 BYTEs   "SOUND-DRIVER-AD-LIB"
 15h    BYTE    01h
 16h    BYTE    01h
 17h    BYTE    00h