The LERC Hanna II experiment uses a multiprogramming system for real-time data acquisition, analysis, and display. Within the framework of the real-time executive program for the computer, time-scheduled user programs are executed and data accumulated. The time scale of the experiment permits averaging of data over one hour intervals, but the sampled data before averaging may be displayed or plotted for observation and control. The data include pressure, temperature, and flow information and online gas analyses. From this information, material balance and other calculations essential to an insight into underground processes may be calculated on demand. Computer control of the position of selected valves has also been utilized.