Soundblaster Instrument Bank (IBK)

 An Instrument Bank File contains information for 128 FM instruments. The
 format is

 ───────────┬────────────────────────────────────────────────────────────────
   Offset   │  Usage
 ───────────┼────────────────────────────────────────────────────────────────
    000-003 │  File ID - 'IBK' + 1Ah
    004-803 │  FM parameters for 128 instruments as elsewhere defined
    804-C83 │  128 Instrument names. 9-byte, null-terminated ASCII strings
 ───────────┴────────────────────────────────────────────────────────────────