Abstract: A peripheral-controller (called a Data Link Processor) optimizes the rate of data transfers between a host computer and magnetic tape peripherals by use of a block counter sensing system for monitoring the occupation-status of word-blocks in a buffer memory. The peripheral-controller provides Automatic Read/Write Logic for buffer-peripheral tape transfers and a burst mode routine for rapid host-buffer transfers of data words. The sensing system provides means to inform a microcode sequencer when certain action routines should be executed in order to maintain steady error-free data transfer operations which minimize the need for retries of data transfer cycles previously initiated.

Abstract: A data transfer system whereby a peripheral-controller manages data transfers between the host computer and a magnetic tape peripheral unit. Data undergoing transit, is temporarily stored in a buffer memory of the peripheral-controller and is monitored by a block counter monitoring system which informs a program-sequencer in the common control circuit unit of the peripheral-controller when data may be shifted into or out of the buffer memory in order to avoid or reduce the probability of access error conditions.