Try the pd software Kinsim, ftp from wuarchive.wustl.edu, in public/kinsim. Also the Bioquest project have a Kinetics simulation for the Mac, Rate It! Fergus Doherty, dept. Biochemistry, University Medical School, Queen's Medical Centre, Nottingham NG7 2UH Tel: 602 709366 FAX 602 422225 Internet: mbxfd at unicorn.nott.ac.uk