We also have been struggling with this question.

 We decided to use the Computer File format for serial CD-ROMS since it
 accomodated most of the serial record needs and also provided important and
 appropriate fixed and variable fields (i.e. fixed fields machine and audience,
 538 technical details note, etc.). Since the Computer File format has a
 different meaning for the 580 field (component part rather than linking entry
 complexity note) and does not provide for 780/785 fields, we made a local
 decision to use a 500 note in lieu of the 580. Since our system (DOBIS) does
 not index 780 or 785 fields we were not concerned about them.

 We are assigning accession call numbers to CD-ROMS: CD-ROM 1, etc.  We do not
 actually barcode or mark the serial CD-ROMS since for practically all of the
 titles, only the latest disc is retained. We have added notes to our serial
 check-in records (Faxon's SC-10) to indicate whether or not previous discs
 are to be returned. Holdings notes are basically "latest issue only". We check-
 in the discs according to the information on the disc itself. For some products
 that may be the period covered (1987-June 1990); for others it may be abstract
 etc. numbers.

 Under normal circumstances, I would simply be cataloging these titles through
 OCLC and they would be added to our OPAC through our routine transfer process.
 However, DOBIS does not accomodate a serial computer file record as of now.
 As I'm sure we all know, the computer file format is like no other MARC format
 in that it has a "tree structure" in the fixed fields with different values
 depending on whether or not the record is identified as a serial or monograph.
 (Local modifications were done to accomodate monographic computer file records;
 more programming would be necessary to handle serial computer
 file formats.)

 Until our system is modified, I will be updating OCLC records to show that we
 own the title and then creating brief catalog records directly in DOBIS to
 add the title to our OPAC.

 The General Libraries has approximately 25 serial CD-ROM products which is more
 than any of the other metropolitan Atlanta libraries.

 Linda Visk
 Head, Serials Control Dept.,
 General Libraries, Emory University, Atlanta GA 30322
 (404) 727-0121  Bitnet: LIBRLV@EMUVM1