SafeBack - Uses with SCSI tape drives.

SCSI (usually pronounced "scuzzy" stands for Small Computer Systems Interface and describes a parallel, bus-oriented peripheral interface protocol. SCSI is a general-purpose interface, not restricted to PCs or a particular device type. Anything from a 9-track tape drive to a page scanner can be hooked to a SCSI bus. Many high-end file servers use SCSI to connect to their disk drives.

There are several flavors of SCSI, but we'll restrict the discussion to SCSI-2, the variety most commonly used by tape drives and other external peripherals. You first need to select a SCSI controller and obtain drivers for it. Unlike IDE, there is no low-level universal standard for SCSI controllers, so one manufacturer's drivers can't usually be used with another's controller.

There are controllers for ISA, VL and PCI buses, as well as for PCMCIA and parallel-port interfaces. If you're assembling a forensics kit, you'll probably want to have at least a parallel (i.e., printer) port SCSI controller, such as the H45 Shuttle, for those times when you can't open a system to insert a card. You'll also want a couple of SCSI adapter cards, such as the Adaptec AVA-1505 or AVA-1515 for ISA bus and the AHA-2940UA for the PCI bus for those times when you can open a system to insert a card. Optional items would be a PCMCIA or USB SCSI controller (for notebooks). Before you buy any controller, make sure that the manufacturer supplies DOS ASPI drivers for use with it!

Avoid the ultra-high-performance controllers. Because they're pushing for the ultimate in speed, these can be difficult to set up and be finicky in cabling and termination requirements. Besides, the performance bonus isn't needed by SafeBack--most tape drives can maintain a streaming speed with a low-end controller.

You also need the ASPI (Advanced SCSI Programming Interface) DOS-mode drivers for your controller. These are usually packaged with the controller and the appropriate driver should be installed in the CONFIG.SYS file of your boot diskette, so SafeBack can see your SCSI devices.

Of course, you'll need the appropriate cables and terminators. A terminator can be thought of as a cable "dead end" to be attached at the end of a SCSI device daisy chain. Terminators come in two flavors-active and passive. If you can, obtain an active terminator for your system; they don't add much to the cost and are worth the superior performance over the passive variety.

A final word on the subject-SCSI is an area of computer "voodoo". Get the equipment and incantations right, and don't fool with your setup. A good tutorial on the subject can be had on the Adaptec EZ-SCSI™ CD-ROM.

NTI does not necessarily endorse Adaptec, H45 Technologies, or DTC products, but offers them simply as examples of widely-available products. There certainly are other competent manufacturers of quality SCSI adapters not mentioned here.