Legacy SCSI devices get an update

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Many organizations -- maybe yours is one of them -- still use legacy SCSI devices such as tape drives or scanners. Granted, in some cases, such as if legacy data can only be accessed through such devices, at least provisionally, they can't be replaced easily.

Rather than install a SCSI adapter to access these devices, some people are electing to attach a device that allows SCSI devices to connect to a PC via a Firewire/1394 interface. The converter generally doesn't need a driver of its own to work properly. If there's an existing Firewire port, then there's no need to open the computer and add a SCSI controller -- especially if there aren't slots free to do so, or if opening the machine poses a logistical difficulty.

How well do they work? My own experiences with such devices have been mixed, but generally positive, so long as you don't try to push the limits of their bandwidth or transfer speed.

For instance, I tried using one such converter box to drive an external SCSI DLT over Firewire and got excellent results. When I installed an Ultra SCSI adapter in the same machine and used that to drive the DLT instead, the machine's CPU utilization went way up and the drive responded far less promptly. Another common use for such devices is to connect a legacy SCSI scanner to a computer when no SCSI controller is available; the scanner may require its own drivers, but otherwise behaves exactly as you'd expect it to.

A few caveats do apply to using a Firewire-to-SCSI bridge. Most such bridges do not support more than 20MB/sec data transfer speeds, and are therefore not suited to driving full-fledged storage devices such as external hard drives. Also, Firewire-to-SCSI interfaces can generally only handle one SCSI device at a time. They are not designed to handle chains of devices.