Working on the labs at home

May of you have expressed a desire to work at home. Although we want you to be present as much as possible at your regular lab session, you can certainly work at home outside of those times as necessary.

To view the lab materials, you will need the Firefox browser, freely available here. The latest version is 1.0. You can also use the mozilla browser, if you prefer.

To run scheme at home, you have several options. We recommend one of two things:

  1. You can get STk and install it on your home machine. The software is available from the instructional support people online at, and can also be installed from a cd-rom (available by the second week of the semester, usually, in 387 Soda). The version of STk on the instructional website automatically loads the extensions that we use in CS3 (e.g., the function word, sentence, etc).

    STk is a very old piece of software, and can act peculiarly; it does, however, give you a syntax-highlighting editor (i.e., one that colors the text differently depending on what that text represents in scheme) and ways for code written in your editor to be evaluated in your scheme listener. With STk, you'll use STk's built in editor, rather than emacs. You can also get emacs to run on microsoft-based home computer, from the instructional site, but we haven't found a way that you can have it interact with STk in a split window.

    If you are running Windows and STk opens and then immediately closes, you need to look in the C:\Program Files\STk folder. This is where you should find the STk program and all of the other files it needs to run. However, the only thing you will probably see here is another STk folder. STk is very picky and will not run unless you move everything from the second STk folder into the main STk folder. Once you do this, STk should run.
    If you are trying to run STk on a Mac and keep getting told that your computer can't find the file, you need to install the X11 binaries. On some versions of Mac OS X (not 10.4), you can do this by going to Install Disk 3, looking under packages, and installing X11User.dgm. For 10.4, you can install it from your Install DVD. If this doesn't help, you can download X11 for 10.1-10.3 here.
  2. Your second option is to make it so our server can show applications on your home computer's screen. For microsoft-based machines, you will need SSH, to start a terminal (like xterm), and eXceed (to let your computer know how to render the application windows). For macintosh computers, you will need X11/XDarwin (to let your computer know how to render the application windows)Both are available on the instructional site. You will want a fast connection to the net for this option.

    Inside the SSH settings for your terminal, you will need to make sure the option for "Tunnel X11 connections" is set. While running your X11 server (eXceed or X11/XDarwin), open up an ssh terminal, login to using your instructional login, and type "STk" to run scheme. You can also type "emacs&" to run our labs emacs, "mozilla&" to run mozilla (although this is slow -- it is better to run firefox or mozilla from your home computer, not from the server). Your home computer will be just like the computers in the lab.

We are exploring other options for you to work at home. For instance, the program Dr. Scheme is a modern and nice scheme, but we haven't yet been able to make it work with our extensions (the functions word, sentence, etc.) We're trying. There may be ways for you to use emacs running on your local computer so that it behaves like it does in lab (with a scheme in a split window, etc) -- but we haven't been able to find out how, yet.

Finally, there is scheme software that we used to use in CS3 that lets you run scheme from inside your Firefox browser. We were unable to maintain the software and fix its minor problems, but we can make it available if you are having trouble making any of these other options work. Tell us.