Technological developments have dramatically reduced the cost of data collection, experimental control and computation. Products are now available which allow automation of experiments both in the laboratory and in the field at substantially lower cost and with less technical expertise required than ever before. One of the developments which has helped to make this possible is a system for connecting calculators, computer, and instruments called HP-IL(Hewlett-Packard Company). The article provides background information for automation of experiments with these kinds products, highlighting the advantages and problems of the new equipment. An overview of HP-IL and products using HP-IL is given, and specific examples implemented using the HP-41 handheld programmable calculator are discussed.