Bison format is really just the format output by Bison seismographs. It can be integer or floating point. However, the floating point is extremely unusual, and I know of no other software than BSU which can process the Bison floats correctly. In particular,
Float 16 bit 2's complement mantissa, 4 bit exponent normalized float generated from 32 bit internal fixed format standard instrument storage format. Transmitted as follows: in groups of 5 words LSbyte of first sample mantissa MSbyte of first sample mantissa LSbyte of second sample mantissa MSbyte of second sample mantissa LSbyte of third sample mantissa MSbyte of third sample mantissa LSbyte of fourth sample mantissa MSbyte of fourth sample mantissa Exponent word: Least significant nibble of first byte for fourth word. Most significant nibble of first byte for third word. Least significant nibble of second byte for second word. Most significant nibble of first byte for first word. One must Check to see if 4 bit exponent is greater than 7 (implies negative exponent in that case). Decode to negative 4 bit number using assumption of 2's complement
If one has a choice, I recommend integer formats for recording and exchange. For exchange, I have used SEGY