The NCR 5380 is an early SCSI controller chip developed by NCR Microelectronics. It was popular due to its simplicity and low cost. The 5380 was used in the Macintosh Plus and in numerous SCSI cards for personal computers, including the Amiga and Atari TT. The 5380 was second sourced by several chip makers, including AMD and Zilog. The 5380 was designed by engineers at the NCR plant then located in Wichita, Kansas, and initially fabricated by NCR Microelectronics in Colorado Springs, Colorado. It was the first single-chip implementation of the SCSI-1 protocol.