KSSX format specification version x.xx based on KSS specification version 'unofficial 1.03'

  KSSX is a music file format for Z80-based sound emulators.
  The normal file extension is .KSS. 
  KSS files can be GZip compressed. 
  The zipped file extension is also .KSS.

  All values are unsigned integers in little-endian.

[Basic Header]
+00 : BYTE[4]: Magic 'KSSX'
+04 : WORD   : LOAD ADDRESS
+06 : WORD   : LOAD SIZE
+08 : WORD   : INIT ADDRESS
+0A : WORD   : PLAY ADDRESS
+0C : BYTE   : start No of the 1st bank
+0D : BYTE   : 8/16K bank mode
        bit 0-6 : number of the extra banks
        bit 7   : 0: 16K mapper / 1: 8K mapper
+0E : BYTE   : extra header size $0 or $10
+0F : BYTE   : Device Flag
	bit 0  : MSX-MUSIC    0: disable
                              1: enable
	bit 1  : SN76489      0: disable
                              1: enable
     if bit1 == 0
	bit 2  : RAM mode     0: disable
                              1: enable
     otherwise
        bit 2  : GG stereo    0: disable
                              1: enable

	bit 3-4: Ext.device   0: none
                              1: MSX-AUDIO
                              2: Majutushi D/A
                              3: MSX-AUDIO (STEREO)
	bit 5  : 0(reserve)
	bit 6  : VSYNC freq   0: NTSC 60Hz
                              1: PAL  50Hz
	bit 7  : 0(reserve)

[Extra Header]
$10 : DWORD  : Offset to the end of file.
$14 : DWORD  : reserved(must be 0).
$18 : WORD   : number of the first song.
$1A : WORD   : number of the last song.
$1C : BYTE   : PSG/SNG volume
$1D : BYTE   : SCC volume
$1E : BYTE   : MSX-MUSIC/FM-UNIT volume
$1F : BYTE   : MSX-AUDIO volume

 volume = $81(MIN)...$E0(x1/4)...$F0(x1/2)...$00(x1)...$10(x2)...$10(x2)...$20(x4)..$7F(MAX)
  (0.375dB/step)