I am a final year student. I want to design a project majority for the production of LED Matrix. The matrix contains four colours: Red, Orange, Yellow and Dark (No power is supplied). The preliminary idea is to make use of 89c52 + 82c55 for implementation. But I'm afraid of how many 82c55 can I use for the extension of output ports without overshoot the limitation of 89c52? In fact, one 82c55 can extend about 24 output ports but it seems not enough for the extension. Can anyone suggest me another ICs, referenece books, web sites for this kind of design?