In this month’s instalment we apply the theoretical knowledge obtained from part 1 to make an 8051 microcontroller drive a matrix display salvaged from a computer game. Because the LCD requires relatively high data speeds, a hardware trick is used to keep the controller software overhead within reason.To prevent flicker, matrix LCDs must be refreshed at frame rates greater than 50 Hz. The concept of the low-cost LCD controller is based on an 8051 microcontroller that creates and keeps an image in its external RAM and then reads the image at the required frame rate. The image databytes read from the external RAM are sent to the LCD display drivers. Clearly, performance optimisation is a major consideration if we are to achieve the required refresh rate and still preserve controller time for other tasks.