StarLogo Maze: A Tour of the Interface

Three main windows (two that matter)

As StarLogo starts up, you'll see a black window (probably labeled something like "StarLogo 1.2" or "cmd.exe"). You won't be using this window, and normally, nothing will ever show up in it, but it's very important that it remain running for StarLogo to work. Never close this black window! (However, you can safely minimize it so it only shows up in the taskbar at the bottom of the screen. Just make sure not to close it.)

The StarLogo graphics window contains a top view of the world (a grid of square patches) your turtle lives in. The turtle is represented by the green square at the center of the world. The Control Center window is how you communicate with the turtle. This window has many more features than you will need for this project, so only the essential ones are described here.

The StarLogo graphics window The StarLogo graphics window shows a top view of the world your turtle lives in, along with some other important information. In the graphics area (the grid of colored, square patches), the green square represents the turtle, black patches are open space, white patches are sections of maze wall, and the violet patch is a maze exit (of which there can be more than one). On the left side of the graphics area, you can see which direction the turtle is heading (north, south, etc.) and how many steps it has taken so far. (The direction "north" is up on your screen, "east" is right, etc.) Clicking the reset button returns the turtle to the center of the graphics area and resets the turtle's step count to 0. The speed slider bar below the graphics area lets you control how fast the turtle moves. Drag the small gray handle on the slider to the right to set the turtle speed faster, left for slower. Below the graphics area, you can also see messages the turtle says to update you on its progress and status. (In this screenshot, the turtle is shown after a step-forward command has been issued, but since the turtle is currently heading east and there is a wall there, the turtle doesn't move and instead says, "My way is blocked!") At the top of the window, there is a toolbar of buttons used for modifying the StarLogo graphics window by adding buttons, sliders, etc. The only button we'll be using later in this project is the paintbrush button (second from the right), and this will be discussed more in an activity handout.

The Control Center window The Control Center window lets you communicate with the turtle to tell it to do things and teach it how to do things. The window has two page tabs, Turtle and Observer, but we will only be using the Turtle page in this project. (In fact, your project file might stop working properly if you make changes on the Observer page, so make sure to stay on the Turtle page.) The Turtle page is split into two sections, the Turtle Command Center in the upper section and Turtle Procedures in the lower section. You use the Command Center to issue commands to the turtle; this is where you tell the turtle what to do. In contrast, the Turtle Procedures section is for teaching the turtle how to do things. This means that typing in the Turtle Procedures section does not directly result in turtle actions; instead, it enables the turtle to understand how to respond to new commands for running later. Turtle Command Center (upper section) You issue a command to the turtle by typing the command in this section of the window and pressing Enter. Some commands result in the turtle moving, changing direction, or saying something in its "turtle message" box. If the turtle has trouble understanding a command you type, an error message will appear immediately below the command here in the Turtle Command Center. The Command Center doesn't erase the commands you type as they are sent to the turtle. If you want to issue a command multiple times, rather than typing it over and over, you can use the arrow keys to move the cursor up to a previously issued command and press Enter to issue it again. (In fact, you can even edit a past command by using Backspace or Delete before issuing it. This will not "undo" the action of the command at is was originally issued.) Turtle Procedures (lower section) This is the section where you'll be typing in your program, in the form of new procedures for your turtle to run. You'll discover how to use this section to teach your turtle new commands in the activities for Units 1 and 2. When you write your procedure code in this section, make sure to add it at the top, as the comments say, and do not change the code that's already there. This code makes things like the turtle direction, step count, turtle message, and speed slider work properly.