I have a hardware, AT89S8252 with 24MHz clock, that control a graphic LCD and a memory AT29C010. I have done a program that transfer data from the PC to AT29C010, by the serial. I transfer the data from PC, put in a array then, when I have 128 bytes, I write to memory. But, when I write the same sequence, for example, write "a" sequence, I have errors. I put a 11,0592MHz crystal to certificate of errors, but this occurs again. When I write different characters, for example, chr(0) to chr(128), I don't have any errors and can write any sectors. What's wrong?