[cctalk] Re: NRAO Data tapes

In my experience, the Qualstar drives aren't the best tool for the job. They're basically a cost-minimized apparatus for handling tapes under the most optimistic of conditions. In particular, they don't really move the tape quickly enough at 6250 fci to get a decent read signal. SCSI drives for data recovery are terrible because they take much of the fine control of the drive away from the user, basically sacrificing control to buffer up as much data as possible. This can entail needless shoe-shining and not returning marginal data (i.e. data with hard errors) to the user. A good Pertec-interface drive and accompanying host controller is the next best thing to interpreting the signal from the drive read heads directly. Many drives have vendor-specific commands that are not exposed with a SCSI interface. My .02 only--your mileage may be different. --Chuck