Abstract: A machine for emulating the results of multi-level storage hierarchies by providing an associative storage directory for each level other than main storage. Address sequences to drive the directories are derived from a single level digital computer by recording sequences on tape or by dynamically monitoring computer operation. Individual addresses are skewed an appropriate number of bits depending upon the block size and the number of classes being emulated at any given level, so that those bits of the monitored address indicating segment name are presented to the directory for comparison with its contents in the appropriate class. Means are provided for transposing the segment and class names at higher levels to segment and class names at lower levels. Counting means are provided to record hits, misses and pushes at various levels in order to provide data for calculating average access times for the particular multi-level storage hierarchy being emulated.

Abstract: A transport system moves documents beneath a self-scanned photocell array extending substantially the entire width of a page. The output data from the photocells is scanned via a plurality of channels, amplified, multiplexed, and converted to a digital format. The digital data is then processed to compensate for fixed pattern errors characteristic of the photocell array and for scan pattern error. The corrected digital data is quantized for character thresholding and input to a recirculating memory. Line-tracking circuitry monitors the location of individual lines of character data within the recirculating memory and gates a complete line of character data into one of two storage registers. While data is input to one register, the contents of the other register is output to character recognition circuitry.

Abstract: A simulation device including a simulation computer is used to simulate peripheral equipment of a real-time system having two stored program computers operating on a load-sharing basis to check and contribute to the development of the two-computer system program. The simulation device includes a time control arrangement containing counters cooperatively arranged with respect to each other and the three computers to check and develop a normally continuously running program by a simulating process which operates in a step-by-step manner and yet maintains the real-time and duration concepts when simulated peripheral equipment is involved in the simulation process and when any time consuming process is simulated.