> Is not not possible to go for a higher PIC which has more I/O so > that we can bypass the usage of 74HC164 ? Yes you could do that. How many rows and columns do you think would be needed for your project ? For mine the shift registers are being used as I/O expanders because of the width of the array and 64 column drives is beyond the capability of a small PIC -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist