• Understanding & Specifying Hi-Density Digital Recording Systems

      Schulze, Glen H.; Bell & Howell (International Foundation for Telemetering, 1977-10)
      Rapid advancement of hi-density digital recording technology has left most user organizations in a confused and bewildered state with respect to understanding and, more importantly, specifying hi-density recording systems. Users attempting to acquire advanced hi-density hardware either without procurement specifications or with incomplete or shallow specifications will probably gain the needed experience too late, after an unusable system has been delivered. Several prominent user facilities have recently bought and accepted hi-density recording hardware and immediately been forced to retire the equipment from use to avoid disastrous embarrassment. Other users have had to redesign accepted equipment before it could be used. One user who blindly accepted a proposal to convert several newly ordered analog recorders to a digital format had to remove and dispose of the digital electronics after delivery and revert back to analog methods. The ability to professionally specify and technically monitor a hi-density recording system contract can only be based upon a thorough understanding of the high density digital coding, recording, reproducing and decoding process. The purpose of this paper is to identify and discuss the more important elements of this emerging technology for users who suddenly find themselves needing this capability.