Variable capacity data buffer system

摘要

A data buffer system is provided for controlling the transfer of data between a processor and an input/output (I/O) device and includes a data storage device having a maximum data storage capacity value. The data storage device is disposed between the processor and the I/O device for receiving data input from the processor and for outputting data to the I/O device to thereby transfer data from the processor to the I/O device. The data storage device temporarily stores a predetermined amount of data while simultaneously transferring data between the processor and the I/O device. Circuitry is provided for selectively establishing a threshold storage capacity value of the data storage device wherein the threshold storage capacity value is less than the maximum storage capacity value of the data storage device. Circuitry is further provided for maintaining the predetermined amount of data temporarily stored in the data storage device equal to the threshold storage capacity value while the data storage device receives data from the processor and outputs data to the I/O device.