First we need to download the source code from HERE

You can find assembly language files along with hex and lst files.  

If you want to modify anyting then you need to use the assembler .

I have used the C51ASM assembler for Windows from Microchip from HERE

C51ASM is also available for Linux and MAC OS from Microchip

C51ASM is a 2 pass assembler same as metalink and produces same checksum without any errors or warning.

To program the hex file into the FLASH of the target microcontroller, we need the WCHISPTool which is available from the WCH website.

We can easily program using USB port which supplies VCC, GND and D+ and D-

For serial terminal application download the Tera Term from HERE

If we are using the onboard USB-TTL feature, we need the driver to recognize by windows. The driver is very generic and can be found HERE

The user can configure the board by populating the required components.

Using machined header is useful for both inserting into a breadboard or into a machined IC socket.