The KS0108 chip and its companion KS0107 device are pretty old technology. It takes one each of these to support a display of only 64x64 pixel size. These days there are multiple choices for single chip controllers (typical of those used on the nice COG type displays) that can support 128x64 or 132x64 resolution.

Do note that sometimes multiple CS signals on the system interface to a module may not imply that there are two controllers on the display module. I have seen at least one example of a display where the manufacturer pinned out two CS signals to the interface from the controller. The KS0108 chip itself actually has three chip select signals which must all be asserted in the correct state to access the part. The data sheet of the controller specified the proper levels.

Often less CS signals appear on the interface of the module than are available on the controller chip itself. This means that the manufacturer has tied the non-available ones high or low as appropriate. This fact alone demonstrates the importance of the need to have two data sheets in hand in order to be successful with applying an LCD module - - - i.e. the data sheet for the module and the datasheet for the controller chip on the module.

Michael Karas