Summary Four field applications of microcomputers are described: (i) a microcomputer system has been developed which allows inclinometer readings to be processed and plotted; (ii) system to monitor and analyse pressuremeter tests uses a microcomputer-based ‘autonomous data acquisition unit’ to log the data, which are simultaneously manipulated, and the results displayed on the graphics screen of a separate microcomputer without interfering with the data logging; (iii) seismic signals are logged by a microcomputer, on which the data can subsequently be processed; (iv) a data logging system has been developed for use with the CSIRO cell to carry out in situ measurements of rock stresses, with an on-site microcomputer plotting and analysing the strain measurements to give the complete stress tensor immediately following overcoring. By using microcomputers not only to collect but also to analyse data in the field, a programme of field tests and also the conduct of individual tests can be improved.