1.Erase the chip with UV eraser for at least 20 minutes. 2.Run software and select M27C64A device from the device list. 3.Click on software menu: File->Open and open your dta file on the CD. 4.Place the erased chip on the programmer ZIF socket. 5.Do a blank check and to confirm the chip is blank. 6.If the chip is blank, then click on write button to wrtie the dta into the chip.