A small digital computer (a Digital Equip. Corp. LINC-8) has been interfaced to voltage clamp control circuitry and a buffer memory in order for it to both control experiments and provide fast and flexible data acquisition. The experiments are designed and run from the computer graphic terminal in a conversational language, offering the experimenter programmed control over input voltage-time patterns and the rate of data sampling. Because many records are usually required and biological preparations tend to deteriorate with time, automated experiment control and faster data acquisition and storage provides more dependable data than manual methods. Subsequent analysis is much more convenient when the data has been stored along with parameters values and labels in a standard format on a digital bulk storage device such as a magnetic tape or disk.