The LCM has built-in a LC7981 LSI Controller, it stores display data sent from the 8 bit microcomputer in the display RAM attached externally and generates dot matrix LC drive signal. The LC7981 has two modes-the graphic mode, in which each bit of data from the external RAM either lights or doesn’t light a dot in the LCD, and the character mode in which character codes stored in the external RAM generate dot patterns through the built-in character-generator ROM (CGROM)
