Appendix B
A Summary of Storage Possibilities


  • low-cost archival storage
  • should experience a rebirth due to use in digital-imaging systems
  • core technology for archival storage on imaging systems for at least the next several years

Magnetic Disk:

  • high-speed random access
  • will continue to be used for high-speed buffer storage and temporary working storage on fileservers and workstations in digital imaging systems

Magnetic Reel Tapes:

  • slow sequential access, low cost
  • will become extinct in five to ten years

Optical Disc:

  • random access, removable, medium speed
  • will be the core data storage technology for providing low-cost random access in imaging systems during the 1990s and beyond
  • archival issue will be solved, obsolescence will require recopying

CD-ROM (660 MB, read-only):

  • stores approximately 330,000 character-coded text-only pages
  • 6,000 to 10,000 300 dpi compressed images
  • ideal distribution and database publishing medium
  • increase in capacity and throughput due shortly

Optical Card:

  • ten MB of laser-written data on credit-card-size card
  • important medium for notebook PCs

Helical Scan Tape (new technology, shows promise for back-up and possible distribution of large data files, including image files):

  • 4mm digital audio tape (DAT) at 1.2 to 2.4 GB
  • 8mm video at 2-5 GB
  • both have robotic handling systems available

New Technology Optical Tape:

  • experimental technology, first deliveries in ’91
  • single 12″ optical tape stores the equivalent of 1,500 CD-ROMs or one terabyte* of data
  • cheaper than any other form of storage; may compete with film for storage of greyscale images in future
  • 28 second average and 60 seconds maximum end-to-end access time claimed