Analyfico Chimica zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Acta, 122 (1980) 103-115 Computer Techniques and Optimization o Eisevier Scientific Publishing Company, Amsterdam - Printed in The Netherlands KISIK - A COMBINED CHEMICAL INFORMATION SYSTEM FOR A MINICOMPUTERt J. ZUPAIW, M. PENCA, M. RAZINGER and B. BARLIC** Boris Kid& Institute of Chemisfry, Ljubkjana (Yugoslavia) D. HAD21 Faculty for Nafural Sciences, Edvard Kanielj University, Ljubljana (Yugoslavia) (Received 7th November 1979) SUMMARY A minicomputer-oriented cbemicsl information system (CIS) based on three different spectrometries, i.e. infrared, mass, and “C-nmr., is described and’discussed- The system has roughly the same characteristics as CIS’s implemented on large mainframe computers: substructure search, library searches on various files, file manipulation, statistical handling of retrieved data, etc. The source package is very suitable and simple for moving the entire CIS from one computer to ano+her. In addition, the system has the option UPDATE that enables the user to create his own files and modify them easily; this is rather difficult and expensive to implement on larger systems because of the very high disk-space price to frequency-of-access ratio. However, the quantity of data is strongly dependent on the disk space. At the moment the system handles 1016 compounds, each of which is described by a chemical name, molecular formula and weight, twodimensional structure image, infrared, mass, and “C-n.m.r. spectra. Ail these data for one compound are linked on-line via tbeidentitynumber of the compound so there is no delay in accessing any of the items mentioned. Tbe entire data bank together with the program package has a 1.8 Mbyte requirement which fits weii within the 2.5 Mbyte space available on the small disk used by a PDP 11/34 minicomputer. Recently, much has been written on the usefulness, benefits and require- ments of chemical information systems (CIS’s). Reviews and descriptions of different systems are available in the literature [l-+5] . The aim of this paper is not to elaborate on all these features but is directed to the description of solutions implemented on a CIS that was designed specially for minicomputers with particular attention to the economy (of space and time) of the data banks and algorithms employed. The CIS in question, KISIK, has been operating in the analytical laboratory for over a year on the minicomputer PDP 11/34 [7] _ The general scheme is shown in Fig. 1. (KISIK is the acronym for the Slovenian words meaning “Chemical Information System of the Institute B. KidriE”. The word KISIK literally means oxygen.) *This paper was presented in part at the International Conference on Computer-based Analytical Chemistry, PortoroZ, Yugoslavia, in September 1979. **Present address: Elektrotehna, TOZD Digital, Ljubljana, Yugoslavia.