NCR 53C9x

The NCR 53C9x is a chipset made by the former NCR Corporation for implementing the SCSI protocol. The 53C9x is a low-cost solution and was therefore widely adopted by OEMs in various motherboard and peripheral device designs; however, the chipset lacks many features commonly attributed as beneficial aspects of SCSI interfaces—for example, the 53C9x lacks Direct memory access (DMA) or bus-mastering capability, and therefore drivers for the chipset consume more processor cycles than those for chipsets which implement such features, due to the necessity of programmed IO.

QLogic FAS216 and Emulex ESP100 chips are a drop-in replacement for the NCR 53C94.

A list of systems which include the 53C9x chipset includes:

53C94

• Sun Microsystems SPARCstations and the SPARCclassic
• DEC 3000 AXP
• DECstations and the PMAZ-A TURBOchannel card
• MIPS Magnum
• Power Macintosh G3 (often used as a secondary SCSI controller with MESH (Macintosh Enhanced SCSI Hardware) as the primary)

53C96

• Macintosh Quadra 650