SCSI stands for Small Computer Systems Interface. Its root can be traced back to Shugart Associates System Interface (SASI), a disk drive and controller manufacturer. Based on the IBM input/output (I/O) channel, the SASI interface was widely received. It was introduced in 1979, when only an 8-bit parallel interface was available. The basic use of SASI was to allow independent peripheral devices to be connected to small and medium-sized computers. In 1982, a formal draft of SCSI based on SASI was developed. Additional capacities were added to make this draft the first generation of the SCSI standard. The new capabilities include peer-to-peer communication, logical units, arbitration, and so on.