The NCR 53C9x is a family of application-specific integrated circuits (

ASIC An application-specific integrated circuit (ASIC ) is an integrated circuit (IC) chip customized for a particular use, rather than intended for general-purpose use, such as a chip designed to run in a digital voice recorder or a high-efficien ...

) produced by the former

NCR Corporation NCR Corporation, previously known as National Cash Register, is an American software, consulting and technology company providing several professional services and electronic products. It manufactures self-service kiosks, point-of-sale termin ...

and others for implementing the

SCSI Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, electrical, optical and logical interface ...

(small computer standard interface) bus protocol in hardware and relieving the host system of the work required to sequence the SCSI bus. The 53C9x was a low-cost solution and was therefore widely adopted by

OEM An original equipment manufacturer (OEM) is generally perceived as a company that produces non-aftermarket parts and equipment that may be marketed by another manufacturer. It is a common industry term recognized and used by many professional or ...

s in various

motherboard A motherboard (also called mainboard, main circuit board, mb, mboard, backplane board, base board, system board, logic board (only in Apple computers) or mobo) is the main printed circuit board (PCB) in general-purpose computers and other expand ...

and peripheral device designs. The original 53C90 lacked

direct memory access Direct memory access (DMA) is a feature of computer systems and allows certain hardware subsystems to access main system memory independently of the central processing unit (CPU). Without DMA, when the CPU is using programmed input/output, it is t ...

(DMA) capability, an omission that was addressed in the 53C90A and subsequent versions. The 53C90(A) and later 53C94 supported the

ANSI The American National Standards Institute (ANSI ) is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organi ...

X3.l3I-I986

SCSI-1 Parallel SCSI (formally, SCSI Parallel Interface, or SPI) is the earliest of the interface implementations in the SCSI family. SPI is a parallel bus; there is one set of electrical connections stretching from one end of the SCSI bus to the oth ...

protocol, implementing the eight bit parallel SCSI bus and eight bit host data bus transfers. The 53CF94 and 53CF96 added

SCSI-2 Parallel SCSI (formally, SCSI Parallel Interface, or SPI) is the earliest of the interface implementations in the SCSI family. SPI is a parallel bus; there is one set of electrical connections stretching from one end of the SCSI bus to the othe ...

support and implemented larger transfer sizes per SCSI transaction. Additionally, the 53CF96 could be interfaced to a single-ended bus or a high voltage differential (HVD) bus, the latter which supported long bus cables. All members of the 53C94/96 type support both eight and 16 bit host bus transfers via

programmed input/output Programmed may refer to: * ''Programmed'' (Innerzone Orchestra album), 1999 * ''Programmed'' (Lethal album), 1990 See also * Program (disambiguation) Program, programme, programmer, or programming may refer to: Business and management * P ...

(PIO) and DMA. 53CF94 SCSI-2 ASIC

QLogic FAS216 and

Emulex Emulex Corporation is a provider of computer network connectivity, monitoring and management hardware and software. The company's I/O connectivity offerings, including its line of Ethernet and Fibre Channel-based connectivity products, are or w ...

ESP100 chips are a drop-in replacement for the NCR 53C94. The 53C90A and 53C(F)94/96 were also produced under license by

Advanced Micro Devices Advanced Micro Devices, Inc. (AMD) is an American multinational semiconductor company based in Santa Clara, California, that develops computer processors and related technologies for business and consumer markets. While it initially manufact ...

(AMD).AMD publication 17348, revision B, May 1993 A list of systems which included the 53C9x controller includes: 53C94 *

Sun Microsystems Sun Microsystems, Inc. (Sun for short) was an American technology company that sold computers, computer components, software, and information technology services and created the Java programming language, the Solaris operating system, ZFS, the ...

SPARCstation The SPARCstation, SPARCserver and SPARCcenter product lines are a series of SPARC-based computer workstations and servers in desktop, desk side (pedestal) and rack-based form factor configurations, that were developed and sold by Sun Microsyst ...

s and the

SPARCclassic The SPARCclassic (Sun 4/15) is a workstation introduced by Sun Microsystems in November 1992. It is based on the sun4m architecture, and is enclosed in a lunchbox chassis. It shares the code name ''Sunergy'' with the SPARCclassic X, SPARCstation ...

DEC 3000 AXP DEC 3000 AXP was the name given to a series of computer workstations and servers, produced from 1992 to around 1995 by Digital Equipment Corporation. The DEC 3000 AXP series formed part of the first generation of computer systems based on the 64- ...

DECstation The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter (more widely known) two both released in 1989. These compri ...

s and the PMAZ-A

TURBOchannel TURBOchannel is an open computer bus developed by DEC by during the late 1980s and early 1990s. Although it is open for any vendor to implement in their own systems, it was mostly used in Digital's own systems such as the MIPS-based DECstation ...

card *

VAXstation The VAXstation is a discontinued family of workstation computers developed and manufactured by Digital Equipment Corporation using processors implementing the VAX instruction set architecture. VAXstation systems were typically shipped with eithe ...

model 60, 4000-m90 *

MIPS Magnum The MIPS Magnum was a line of computer workstations designed by MIPS Computer Systems, Inc. and based on the MIPS series of RISC microprocessors. The first Magnum was released in March, 1990, and production of various models continued until 1993 w ...

Power Macintosh G3 The Power Macintosh G3 (also sold with additional software as the Macintosh Server G3) is a series of personal computers designed, manufactured, and sold by Apple Computer from November 1997 to August 1999. It represented Apple's first step tow ...

; often used as a secondary SCSI controller with MESH (Macintosh Enhanced SCSI Hardware) as the primary *MacroSystem's Evolution family for

Amiga Amiga is a family of personal computers introduced by Commodore in 1985. The original model is one of a number of mid-1980s computers with 16- or 32-bit processors, 256 KB or more of RAM, mouse-based GUIs, and significantly improved graphi ...

(FAS216) 53C96 *

Macintosh Quadra The Macintosh Quadra is a family of personal computers designed, manufactured and sold by Apple Computer, Inc. from October 1991 to October 1995. The Quadra, named for the Motorola 68040 central processing unit, replaced the Macintosh II family as ...

650 * Macintosh LC475/Quadra 605/Performa 475 *

Macintosh Quadra 900 The Macintosh Quadra 900 is a personal computer designed, manufactured, and sold by Apple Computer from October 1991 to May 1992. It was introduced alongside the Quadra 700 as the first computers in the Quadra family of Macintosh computers usin ...

and 950

References

{{Reflist SCSI Integrated circuits NCR Corporation products