Friends, I need your generous helps. I am working on an ISD1420 voice chip which is controlled by AT89C51. I can record and playback the voice. The problem is when I recorded more than two messages into this chip and want to playback the certain message, why only the first message can be playbacked? I know I should care about the THOLD of ISD1420 (using delay function), but it did not work. Do you have any idea? Please save me. Thank you in advance.