Presentations at recent conferences have also highlighted the data publication potential of Compact Disk Read Only Memory (CD ROM), also known as OROM (Optical Read Only Memory). Under standards developed by Philips and Sony, a 12 cm (4 1/2 inch) single—sided disc can carry 575 MB of usable data; capacities of up to 800 MB per side are under development. Apparently, the disks can hold up to 1 GB (Gigabyte, or 1 billion characters) of data but usable capacity is diminished by the redundancy and error checking used in recording the data for mastering. The disk is, like regular phonograph records and videodiscs, a read-only medium. The technology is simple, is rapidly becoming established, and is expected to be on the market within several months.
The principal disadvantage of CD-ROM is its comparatively slow access times. CD ROM appears to support an average access time of between 1/10 to 1 second, with a worst case access time of 4 seconds. In contrast, Winchester technology offers access speeds of 30 to 50 milliseconds.
Speaking in October at the ASIS meeting in Philadelphia, Rick Simon of BRS told of his company's interest in digital data publishing on CD-ROM as well as videodisc. BRS sees read only digital publication as an opportunity to achieve more use and sales of its software.
There are two places in the digital publishing chain where BRS could offer services. First, in the formatting of the digital data prior to its transfer to videodisc or CD ROM. A raw machine-readable data base must be formatted before it is ready to be searched. Through its online activities BPS has developed the software for the formatting of files and the creation of dictionaries and inverted file indices. Both full text and bibliographic files can be processed by BRS [Experience shows that raw machine—readable data can be processed through the BRS system at a rate of 50 MB in four hours, and that such processing normally results in an output file one-and-a-half times the size of the input file, although smaller increases—an overhead of 33 percent rather than 50 percent—have been achieved on some fulltext files.] BRS' second area of interest is the sale of its SEARCH retrieval software. If data base providers/publishers were to specifically design their files in a way that would require the use of BRS/SEARCH for their most efficient access and effective utilization, then BPS would enjoy increased sales of SEARCH from users wishing to access those electronic publications. Another option would be to publish the BRS SEARCH software on the disc along with the data.