This paper describes the design and implementation of a versatile and compact signal averager interface between a Biomation 6500 transient recorder and an LSI‐11 microcomputer. The design allows for fast signal averaging in excess of 1 kHz and is also easily software configurable and controllable. This permits the rapid recovery of high‐speed waveforms at a minimum sampling time of 2 ns (500 MHz sampling rate). The interface has been incorporated into an LSI‐11 system using the RT‐11 V3B operating system and found to perform very satisfactorily.