I AM USING AT89C51 BUT THE DIFFICULTY I HAVE THAT 1> AFTER USING BATTERY SUPPLY I CHECK THE CLK PULSE AT PIN NO. 18 OF PIN.(CRYSTL OF 12MHZ). BUT I DIDN'T GET THE WAVEFORM CORRECTLY. 2> I WROTE SIMPLE PROGRAMME OF BIT ON OF WITH 5MSEC DELAY BUT THERE IS NO ANY VOLTAGE CHANGES AT THAT PIN. THE PROGRAMMING I AM USING FLASH V3.4 PLEASE SEND ME THE INFORMATION FOR THE PROBLEM I GOT.