In this tutorial we see how to setup Keil4 for generating .hex file.
Keil software can be downloaded from this link.
Download and install the Keil C51 for 8051.

Keil Setup Steps

Step1: Open the Keil software and select the New Microvision project from Project Menu as shown below.

Step2: Browse to your project folder and provide the project name and save it.

Step3: Once the project is saved a new pop up “Select Device for Target” opens, Select the required 8051 series controller and click on OK.

Atmel->AT89s52
NXP->P89V51RD2
Nuvoton-> W78E052D

Since all the controller follow the same 8051 architecture, any of the above mentioned controller can be selected.

Step4:Select Atmel->At89s52 and click OK.

Step5:8051 doesn't need the startup code, click on NO option to proceed.

Step6: Create a new file to write the program.

Step7: Type the code or Copy paste the below code snippet and save the file as main.c

	#include <reg51.h>

	void DELAY_ms(unsigned int ms_Count)
	{
	unsigned int i,j;
	for(i=0;i<ms_Count;i++)
	{
	for(j=0;j<100;j++);
	}
	}
	int main()
	{

	while(1)
	{
	P0 = 0xff; /* Turn ON all the leds connected to Ports */
	P1 = 0xff;
	P2 = 0xff;
	P3 = 0xff;
	DELAY_ms(500);

	P0 = 0x00; /* Turn OFF all the leds connected to Ports */
	P1 = 0x00;
	P2 = 0x00;
	P3 = 0x00;
	DELAY_ms(500);
	}

	return (0);
	}