A method, at a host device (10), of managing memory (28) of a display control device (16), the memory (28) being used for storing display data sent from the host device (10) to the display control device (16) for display. The method involves maintaining a map (18) at the host device (10) corresponding to the memory (28) at the display control device, the map (18) indicating locations corresponding to addresses of the memory (28) at which data is stored or not. The map (18) is used to determine a size of a portion of the display data, and a location on the map (18) where the portion of display data would fit into the memory. An address in the memory (28) corresponding to the determined location on the map (18), together with the portion of display data, is then sent to the display control device (16), and the location on the map (18) corresponding to the address in the memory (28) is updated to indicate that the address has data stored in it. The data may be compressed using compression parameters, which can be selected so that the compressed portion of display data will fit into a free space in the memory (28) of the display control device (16).