Ask THE SCSI EXPERT.Visit the SCSI SCSI in full Small Computer System Interface Once common standard for connecting peripheral devices (disks, modems, printers, etc.) to small and medium-sized computers. SCSI has given way to faster standards, such as Firewire and USB. Trade Association's web site (www.scsita.org) to ask the SCSI Expert a question. Q: How many SCSI devices (scanner, hard drive, etc.) is it possible to plug into a computer? A: The answer depends on whether the SCSI device is narrow or wide. If you have a narrow SCSI host adapter The controlling electronics for SCSI contained on a printed circuit board that plugs into the computer's motherboard. A SCSI host adapter is often called a "SCSI controller." See SCSI. (8-bit, with 50-pin SCSI connector) you can connect up to eight devices. This is usually one host (at ID=07) and up to seven peripherals. If you have a wide SCSI host adapter (16-bit, with 68-pin SCSI connector), you can connect up to 16 devices. This is usually one host (at ID=07) and up to 15 peripherals. There are other technical reasons that could limit the number of active IDs on a wide bus to less than 16. If you are using a RAID controller or a LUN bridge, the controller appears as one address, and can have up to 64 devices on the secondary buses. Q: Often we need more than four channels. Can a SCSI card be added to an EIDE (Enhanced IDE) An extension to the IDE interface that supports the ATA-2 and ATAPI standards. ATA-2 (Fast ATA) provides faster transfer rates (see IDE for details) and allows for multiple channels, each connecting two devices. system successfully? Using this for items such as CD-R/RW and tape drives would be helpful, leaving the other channel open for hard drives. I also have a system that uses a mirror drive which take up two channels. A: Yes. You need only purchase a SCSI host adapter for the bus in your PC and install it. Many companies manufacture SCSI HBAs, including Adaptec, Advansys, Data Technology, DPT, Mylex (owned by IBM (International Business Machines Corporation, Armonk, NY, www.ibm.com) The world's largest computer company. IBM's product lines include the S/390 mainframes (zSeries), AS/400 midrange business systems (iSeries), RS/6000 workstations and servers (pSeries), Intel-based servers (xSeries) ), QLogic, TekRAM, and others. Note: If disk drives are installed on the SCSI bus, they will appear as drive letters after the IDE devices. Most systems can only boot the operating system from Drive C which will be the IDE disk. Q: Will Ultra2 SCSI support an Ultra160 SCSI hard disk drive? A: Ultra160 SCSI is backward compatible with Ultra2 SCSI. You simply plug the Ultra160 SCSI drive into the Ultra2 SCSI bus. Your data throughput will, of course, be limited to the maximum data throughput of Ultra2 SCSI. In order to get Ultra160 SCSI data throughput, you must have a host adapter that is Ultra160 SCSI capable. Q: We want to use four PCs and four SCSI disks in a single SCSI string. We are looking for Looking for In the context of general equities, this describing a buy interest in which a dealer is asked to offer stock, often involving a capital commitment. Antithesis of in touch with. a SCSI-3 adapter and disks that support a differential (High Voltage Differential (hardware) High Voltage Differential - (HVD) Differential SCSI scheme that has been in use for years. The terminators run on 5 Volts DC. See also LVD. ) connection. Could you recommend a resource to find such a product? We are having difficulty finding HVD (1) (High Voltage Differential) See SCSI and differential signaling. (2) (Holographic Versatile Disc) A high-capacity optical disc from the HVD Forum (www.hvd-forum. SCSI-3 adapter and disks. A: WVD WVD Wigner-Ville Distribution WVD Waived WVD Wavelet-Vaguelette Decomposition SCSI is obsolete in the current generation of the SCSI standards. One of the few HVD SCSI host bus adapters left on the market is the Adaptec AHA2944. It is limited to UltraSCSI speeds. It is possible to run multi-initiator systems; however, the bus activity would affect the performance of the system. Connecting four systems together would not be a good performance system. SPC 1. (business) SPC - Statistical Process Control. Something to do with quality management. 2. (body) SPC - Software Productivity Centre. 3. (company) SPC - Software Publishing Corporation. 4. (SCSI Primary Commands) reservation would have to be used to insure that the data is only written on the disk from one system to insure two or more systems are not trying to write to the same sector on the same disk. Most initiators are only set up for addresses six or seven, not for a range of four addresses. I would not recommend this configuration, even if you find hardware to support it. 
I have an 80 pin SCSI drive connected to a 160 SCSI controller card through an adapter that attaches to the rear of the drive. No matter what I try I can only get it to run at 40 MBPS! I know that I have the right cable, so why is this?<br> <br>Any help would be greatly appreciated.<br> <br> Bob
I have an 80 pin SCSI drive connected to a 160 SCSI controller card through an adapter that attaches to the rear of the drive. No matter what I try I can only get it to run at 40 MBPS! I know that I have the right cable, so why is this? Are there additional jumpers that must be set besides the SCSI ID jumpers?<br> <br>Any help would be greatly approached.<br> <br> Bob |
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