KEYBOARD UNIT CONTROL SYSTEM

摘要

A keyboard unit control system having a port which includes a block selection register for specifying one of a plurality of blocks of scanning lines and a scanning data selection register for specifying one of the scanning lines of the corresponding block. The scanning data and block data are supplied to a keyboard unit through the scan line selecting logic. When the operator depresses a key on the keyboard unit, the key is detected by an interrupt detector and a detection signal is supplied to a CPU. The CPU first scans the blocks and then scans the scanning lines in the corresponding block.