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 Voyix Corporation, previously known as NCR Corporation and National Cash Register, is a global software, consulting and technology company providing several professional services and Electronics, electronic products. It manufactured Self-c ...

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, best known for its use with storage devices such as hard disk drives. SCSI was introduced ...

(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 OEMs in various

motherboard A motherboard, also called a mainboard, a system board, a logic board, and informally a mobo (see #Nomenclature, "Nomenclature" section), is the main printed circuit board (PCB) in general-purpose computers and other expandable systems. It ho ...

and peripheral device designs. The original 53C90 lacked

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

(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 nonprofit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States. The organiz ...

X3.l3I-I986 SCSI-1 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 o ...

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

QLogic QLogic Corporation was an American manufacturer of networking server and storage networking connectivity and application acceleration products, based in Aliso Viejo, California through 2016. QLogic's products include Fibre Channel adapters, c ...

FAS216 and

Emulex Emulex Corporation was an American computer hardware company active from 1978 to 2015. The company was a provider of computer network connectivity, monitoring and management hardware and software. The company's I/O connectivity offerings, inclu ...

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 corporation and technology company headquartered in Santa Clara, California and maintains significant operations in Austin, Texas. AMD is a Information technology, hardware and F ...

(AMD). A list of systems which included the 53C9x controller includes: 53C90A *

Sony is a Japanese multinational conglomerate (company), conglomerate headquartered at Sony City in Minato, Tokyo, Japan. The Sony Group encompasses various businesses, including Sony Corporation (electronics), Sony Semiconductor Solutions (i ...

PlayStation (console) The (codenamed PSX, abbreviated as PS, and retroactively PS1/PS one) is a home video game console developed and marketed by Sony Computer Entertainment. It was released in Japan on December 3, 1994, followed by North America on September 9, ...

Prototype (PS-X DTL-H500) *NeXT

NeXTstation NeXTstation is a high-end workstation computer developed, manufactured, and sold by NeXT from 1990 until 1993. It runs the NeXTSTEP operating system. The system was designed to be a lower-cost option compared to the company's upscale product, t ...

(25MHz) 53C94 *

Sun Microsystems Sun Microsystems, Inc., often known as Sun for short, was an American technology company that existed from 1982 to 2010 which developed and sold computers, computer components, software, and information technology services. Sun contributed sig ...

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

s and the SPARCclassic *

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 6 ...

DECstation The DECstation was a brand of computers used by Digital Equipment Corporation, 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 ...

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 19 ...

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 Inc., Apple Computer from November 1997 to August 1999. It represented Apple's fi ...

; 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 produced by Commodore International, Commodore from 1985 until the company's bankruptcy in 1994, with production by others afterward. The original model is one of a number of mid-1980s computers with 16-b ...

(FAS216) 53C96 *

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

650 * Macintosh LC475/Quadra 605/Performa 475 * Macintosh Quadra 900 and 950

References

{{Reflist SCSI Integrated circuits NCR Corporation products

See also

References