A graphic editor file lets you draw schematics. The symbol editor lets you draw symbols that represent an entire design. So you could define some odd function and represent it with a single symbol in other schematics. You can use the text editor to work with any text file, some of which may contain design information. The waveform editor is primarily for testing simulated designs.

In this case, you want a Graphic Editor File with a .gdf extension, so simply press OK.

MAX PLUS II uses the base name of the file as a project name. So the first thing I like to do is save the empty file to start a new project. Press File | Save As. Navigate to the directory where you want to store the file and give it a name. In this case, I'm going to f:\postit\hadd and I'll name the file hadd.gdf.

To make sure the project is set correctly, pick File | Project | Set Project to Current File (or press Shift+Control+J). The top of the MAX PLUS II window should show the current project name (f:\postit\hadd\hadd in my case).

Now you are ready to draw the schematic. Click somewhere in the GDF file to set the insertion point. Then double click anywhere in the window. You'll see this dialog:

You can browse through the symbols, but in this case, I know I want an xor gate (an exclusive or with 2 inputs), so I just typed xor in directly). Then press OK. The GDF file looks like this:

Next add the AND gate in the same way (use and2 as the symbol name). Place the cursor over the pin stubs (the little wires) and click and drag to draw interconnecting wires. When you are done, it should look about like this:

Notice the name of the symbol appears at the top left of each box. At the bottom right is a sequence number. Your numbers will not match my numbers if you enter the gates in a different order than I do. However, there is no harm in these numbers not matching my numbers. In the next frame, we'll add inputs and outputs.