SCSI Adapters and SCSI Controllers Specifications

Help with SCSI Adapters and SCSI Controllers specifications:

Bus / Interface Type


	Bus / Interface Type
	Your choices are...
	ISA / EISA		Industry standard architecture (ISA) buses can handle 16-bit data transfers at a clock speed of 8 MHz. They are also capable of handling memory under 16 MB. Extended ISA (EISA) is an enhanced version of the ISA bus. EISA buses run at 8 MHz, are capable of 32-bit data transfers, and can access all memory in the system.
	MCA		The MCA bus, which was designed to replace the ISA bus, uses IBM's microchannel architecture (MCA). It is capable of plug-and-play because adding a card to a microchannel computer does not change the interrupt and DMA settings on the card. The MCA bus was used almost exclusively with IBM's PS/2 product line, but is now discontinued.
	PCI		Peripheral component interconnect (PCI) is a local bus system designed for high-end computer systems. PCI buses transfer 32 or 64 bits of data at a clock speed of 33 MHz. They also support 3 to 5 critical peripherals, which are either integrated directly onto the motherboard or added via expansion cards. PCI buses fully support cards that were developed for standard I/O buses.
	*PC/104 (PC/104-Plus, EBX, ETX)*		PC/104 derives its name from the acronym for personal computers (PC) and the number of pins used to connect cards (104). PC/104 cards are much smaller than ISA bus cards and stack together, eliminating the need for a motherboard, backplane, and/or card cage. PC/104-Plus combines the PCI bus with the PCI/104 form factor for faster data transfers. Embedded board expandable (EBX) is a small (5.75” x 8”) form factor for single-board computers that supports PC/104 expansion.
	Parallel Interface		A channel capable of transferring more than one bit simultaneously.
	PCMCIA Type I		PCMCIA, Type I devices are 3.3 mm thick. They are used, primarily, as memory cards.
	PCMCIA Type II		PCMCIA, Type II devices are 5.0 mm thick. They are used in I/O devices and as high-capacity storage drives and memory cards.
	PCMCIA Type III		PCMCIA, Type III cards are 10.5 mm thick. They are used in I/O devices and as high-capacity storage drives and memory cards.
	PCMCIA (PC Card) / CardBus		PCMCIA devices or PC cards are credit card-sized peripherals used mainly in laptop and notebook computers. They plug into a 68-pin host socket that is connected either to the motherboard or an expansion bus. An adapter takes the place of a COM port and translates the PCMCIA signals into a format that is usable by the computer’s bus. PC cards adhere to standards developed by the Personal Computer Memory Card International Association (PCMCIA). Originally, these standards were designed for adding memory to portable computers; however, standards now apply to many types of devices. There are three types of PC cards: Type I, Type II, and Type III. All types have the same width (54 mm) and length (85.6 mm), but vary in thickness. Cardbus, a 32-bit high performance bus architecture for PC cards, adds high bandwidth capabilities to PCMCIA devices.
	Other		Other unlisted, specialized, or proprietary configuration.
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SCSI Standards

SCSI Standards

See tables at the end of this help file for definitions of several features of SCSI standards.

Your choices are...

SCSI-1

SCSI-1, the original SCSI, was standardized by ANSI in 1986. It allows asynchronous data transfer rates of 1.5 MB/sec and synchronous transfer rates to a maximum of 5 MB/sec. It has an 8-bit SCSI port that uses Single-ended open-collector drivers. Uses a 50-pin connector. SCSI-1 is an obsolete standard after the development of SCSI-2.

Wide SCSI

This term is generally applied to Wide (16-bit) SCSI with a fast data transfer rate of up to 10 MBps.

Fast SCSI

Standard defined in SCSI-2. Increases the maximum data rate from 5 MBps for Narrow (8-bit) SCSI to 10 MBps.

Wide Fast SCSI

This term is generally applied to Wide (16-bit) SCSI with a fast data transfer rate of up to 20 MBps.

Ultra SCSI

This is also known as Fast-20. It doubles the FAST SCSI data rate to up to 20 MBps for the 8-bit bus

Wide Ultra SCSI

Wide Ultra SCSI defines a maximum transfer data rate up to 40 MBps for the Wide (16-bit) SCSI.

SCSI-2

SCSI-2 has significant improvements over SCSI-1 including faster data transfer rates, better connectors, wider bus path, better reliability via synchronous negotiation and parity checking. SCSI-2 has a data transfer rate from 5 MB/sec to 10 MB/sec. This speed change is called Fast SCSI-2. Also, SCSI-2 provides the option to double the bus from 8 bits to 16 bits. This change is known as Wide SCSI. By combining the Fast SCSI-2 with the Wide SCSI bus a maximum data rate of 20 MB/sec can be achieved.

Ultra2 SCSI

This is also known as Fast-40. It doubles the Ultra SCSI data rate to up to 40 MBps for the 8-bit bus.

Wide Ultra2 SCSI

Wide Ultra2 SCSI defines a maximum data rate of 80 MBps for the Wide (16-bit) SCSI.

SCSI-3

The SCSI-3 specification allows for faster transfer rate, more devices on a single chain (a maximum of 32), and also it incorporates serial connections in addition to the traditional parallel interconnect of SCSI-2. The serial interconnect of SCSI-3 incorporates three technologies: Serial Storage Architecture (SSA), Fibre Channel, and IEEE P1394. The serial transfer mode allows faster data rates, more devices per bus, simple connectors, and longer cables.

Ultra3 SCSI (Ultra160)

This is also known as Fast-80 or Ultra-160. It doubles the Ultra2 SCSI data rate to up to 160 MBps for the 16-bit bus.

Ultra320 SCSI

Defines a maximum data rate of 320 MBps for the Wide (16-bit) SCSI.

Ultra640 SCSI

Defines a maximum data rate of 640 MBps for the Wide (16-bit) SCSI.

Fibre Channel

A high-speed serial protocol for channels and networks that uses links of twisted-pair, coaxial cable or fiber optic cable. SCSI can use the Fibre Channel Arbitrary Loop (FC-AL) topology.

Serial SCSI (FireWire®)

A very fast bus standard that supports data transfer rates of up to 400 Mbps. FireWire is a registered trademark of Apple Computers, Inc. The standards are defined in IEEE 1394.

Other

Other unlisted, specialized, or proprietary SCSI standards.

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Tables:

Bus Width

Bus Width
Width	Definition
Narrow	Narrow SCSI is the conventional SCSI specified in the original SCSI. The bus width is 8 bits.
Wide	Uses a data bus that is 16 bits wide. This doubling of the bus width respect to the Narrow SCSI comes at a higher cost, and it requires additional cabling and connectors.

SCSI Type

SCSI Type
Type	Definition
SCSI-1	SCSI-1, the original SCSI, was standardized by ANSI in 1986. Allows asynchronous data transfer rates of 1.5 MB/sec and synchronous transfer rates to a maximum of 5 MB/sec. It has an 8-bit SCSI port that uses Single-ended open-collector drivers. Uses a 50-pin connector. SCSI-1 is an obsolete standard after the development of SCSI-2.
SCSI-2	SCSI-2 has significant improvements over SCSI-1 including faster data transfer rates, better connectors, wider bus path, better reliability via synchronous negotiation and parity checking. SCSI-2 has a data transfer rate from 5 MB/sec to 10 Mb/sec. This speed change is called Fast SCSI-2. Also, SCSI-2 provides the option to double the bus from 8 bits to 16 bits. This change is known as Wide SCSI. By combining the Fast SCSI-2 with the Wide SCSI bus a maximum data rate of 20 MB/sec can be achieved.
SCSI-3	The SCSI-3 specification allows for faster transfer rate, more devices on a single chain (a maximum of 32), and also it incorporates serial connections in addition to the traditional parallel interconnect of SCSI-2. The serial interconnect of SCSI-3 incorporates three technologies: Serial Storage Architecture (SSA), Fibre Channel, and IEEE P1394. The serial transfer mode allows faster data rates, more devices per bus, simple connectors, and longer cables.

Bus Speed

Bus Speed
Speed	Definition
Regular	This is the default speed of the original specifications of SCSI-1. The regular bus speed is 5 MHz.
Fast	Fast SCSI increases the bus speed to 10 MHz. This doubling of the bus speed was defined in SCSI-2.
Ultra	Also known as Fast-20, it is specified in SCSI-3. The bus speed of Ultra SCSI is 20 MHz. Ultra SCSI buses have a maximum transfer rate of 20 MB/sec for Narrow SCSI, and 40 MB/sec for Wide SCSI.

SCSI Standards

SCSI Standards
			Maximum Bus Lengths (meters)			Max Devices Supported
Protocol	Max Speed (MBps)	Bus Width (bits)	Single-ended	LVD	HVD
SCCI-1	5	8	6	--	--	8
Fast SCSI	10	8	3	--	25	8
Fast Wide SCSI	20	16	3	--	25	16
Ultra SCSI	20	8	1.5	--	25	8
Wide Ultra SCSI	40	16	3	--	--	8
Ultra2 SCSI	40	8	--	12	25	8
Wide Ultra2 SCSI	80	16	--	12	25	16
Ultra3 SCSI (Ultra 160)	160	16	--	12	--	16
Ultra 320	320	16	--	12	--	16

Computer Platform - Operating System


	Operating System:
	Your choices are...
	Windows® 95 / 98		Microsoft® Windows® 95 / 98 operating system uses a graphical user interface to control the system.
	MS-DOS		MicroSoft Disk Operating System (MS-DOS®) is a command line operating system developed by the Microsoft Corporation.
	Windows NT®		Operating system developed by the Microsoft Corporation. It uses a graphical user interface to control the system.
	Windows® 2000		Operating system developed by Microsoft® Corporation. It uses a graphical user interface to control the system.
	Mac® OS		Macintosh operating system developed by Apple Computer, Inc.
	NetWare®		A local area network (LAN) operating system developed by Novell Inc. NetWare runs on a variety of different types of LANs such as Ethernets, Token rings, etc.
	OS/2		An operating system developed by the Microsoft Corporation and the IBM Corporation, but sold and managed solely by IBM.
	Linux		An open-source UNIX clone operating system that runs on machines powered by the x86 microprocessor.
	SUN Solaris		A Unix-based operating system environment developed by Sun Microsystems. Solaris runs on many workstations from vendors other than Sun Microsystems
	SCO UNIX (x86)		A Unix-like operating system that runs on x86 machines.
	Other		Other unlisted, specialized, or proprietary configuration.
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Computer Platform


	Computer Platform:		Type of computer system or operating system.
	Your choices are...
	PC		The 8086 type of machines running the DOS or Windows® operating system. Windows is a registered trademark of the Microsoft Corporation.
	Mac		Macintosh systems.
	Alpha		Machines that use with the Alpha processor developed by Digital Equipment Corporation. Alpha is a powerful RISC processor used in servers and workstations. This is one of the few processors, other than the x86 microprocessors, that runs Windows® NT.
	SPARC®		Scalable Processor Architecture (SPARC®) is a RISC technology developed by Sun Microsystems.
	Other		Other unlisted, specialized, or proprietary configuration.
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Other Specifications


	Data Transfer Rate:		The maximum data transfer rate (MB/sec) of the SCSI device.
	Search Logic:		All matching products will have a value greater than or equal to the specified value.

	Data Transfer Mode?		The method of transferring data from the SCSI Adapter to the system. There are three modes of transferring data: PIO Programmed I/O (PIO), Bus Master DMA, and Interrupt Transfer.
	Your choices are...
	Bus Master DMA		A method of transferring data in which the host adapter's processor transfers the data directly to the computer memory without the intervention of the CPU. DMA transfer uses the DMA controller instead of the CPU to move the data. This is also called bus mastering or first party DMA.
	PIO		For programmed Input / Output transfers, the CPU sends the data when it receives a software code.
	Interrupt		Interrupt data transfer occurs when the PC receives an interrupt telling the CPU to move the data.
	Other		Other unlisted, specialized, or proprietary configuration.
	Search Logic:		Products with the selected attribute will be returned as matches. Leaving or selecting "No Preference" will not limit the search criteria for this question; products with all attribute options will be returned as matches.

SCSI Adapters and SCSI Controllers Specifications

Bus / Interface Type:

SCSI Standards:

Computer Platform:

Data Transfer Rate:

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