SELECTING CIRCUIT OF CHARACTER GENERATOR

摘要

The circuit provides a common CRT display interface which can select ROM or RAM used for a character generator. The circuit comprises: a buffer (10) inputting addresses (A0-A7) from CPU and a latch circuit (40) inputting addresses (CA0-CA7) from a CRT controller, both being connected to the character generator (50), a multiplexor (20) inputting (A0-A3) and raster addressed (RA0-RA3) from the CRT controller and being connected to other address node of (50). CPU control signal (C1) is supplied to buffer (10)(30) and latch circuit (40) enable nodes. Data read/write signal is supplied to data writting enable node of character generator (50).