This is not the standard MS-Windows clipboard, by the way. Copy command copies the currently marked text to the editor's internal clipboard. This is not the standard MS-Windows clipboard, by the way. Paste command copies the text currently in the clipboard into the current location of the active window. This shows the contents of the clipboard in a window.
Clear command removes all currently marked text.
The erased text is NOT placed in the clipboard. In general, these commands work in the same manner as any standard text editor. By default, the Microsoft Assembler will run, but you can optionally select another assembler. You must set the default directory to the location of your source file before assembling and linking the program. The assembler reads the file directly from disk, not from memory.