AbstractThis paper presents the principles of a portable compact instrument utilizing a digital control system and providing B‐scan displays. The instrument is designed exclusively for ophthalmic applications. The system is comprised of a self‐contained scanning head and a signal display unit. The entire unit can easily be rolled to the patient's bedside or into the operating room. A programmed pulse generator provides signals for incremental angular positioning of the transducer as well as signals for the formation of the display. The transducer is moved by a stepping motor to establish the incremental sector scan. Display sweeps are generated by digital‐to‐analog conversion to circumvent the use of mechanically‐driven position sensors as used in conventiona