The Johns Hopkins University High Resolution Scanning Transmission Electron Microscope is serviced by a real-time dedicated digital data acquisition and display system. This system, whose block diagram is shown, is capable of accepting three eight-bit data samples from each scanning element of the microscope sweep. A major component of the system is a Digital Equipment Corp. PDP-11/20 processor and peripherals. The relevant peripherals, communicating with the machine's 12 K word, 900 nS core memory, are a disk storage unit of 1.2 M word capacity and two direct memory access interface units. Also participating, but not shown, are a hardware arithmetic unit and a magnetic tape unit. All of these are standard D. E. C. items. The storing scan converter, by Princeton Electronic Products, Inc., and its monitor are also purchased items.