The main objective of this project is the application of computer graphics and related methods to NIH research problems. The GRAPH and DNADRAW programs, heavily used on the DEC-lO computer for the past five years, are being rewritten for the IBM-PC. This involves not only reprogramming, but considerable redesign, to take advantage of the many features offered by the user-friendly environment of the PC. The C language is being used, so that the programs should be portable to other machine environments with a minimal amount of additional work. At present, about one-third of the GRAPH program has been completed, and a much superior version of the FORMAT option of DNADRAW is now running on the PC. Consulting has been done mainly with users of the DNADRAW program. In addition, work was done with Dr. Roger Miller of NIAID, based on the publication cited above, to predict the location of splice sites in genes coding for the Hepatitis B virus.