The 8051 Cross Assembler takes an assembly language source file created with a text editor and translates it into a machine language object file. Just upload the Assembly file and download the Hex file and the List file for your assembly program. Online Assembler for 8051 MicrocontrollersĬlick here to Assemble your 8051 microcontroller based programs online. 8051 Microcontroller Simulator For Windows 10.