The MC141540 is a high performance HCMOS device designed to interface with a microcontroller unit to allow colored symbols or characters to be displayed on a color monitor. The onchip PLL allows both multisystem operation and selfgeneration of system timing. It also minimizes the MCU's burden through its builtin 273 bytes display/control RAM. By storing a full screen of data and control information, this device has a capability to carry out `screenrefresh' without MCU supervision. Since there is no spacing between characters, special graphicsoriented characters can be generated by combining two or more character blocks. Special functions such as character bordering or shadowing, multilevel windows, double height and double width, and programmable vertical length of character can also be incorporated. Furthermore, neither massive information update nor extremely high data transmission rate are expected for normal on screen display operation, and serial protocols are implemented in lieu of any parallel formats to achieve minimum pin count.