Exam1 makeup homework

Due December 7th, 1999 at midnight.

This will be graded out of 8 points. When you have completed this makeup homework and want it graded, send email to

  cs2a@cs.brandeis.edu

  Please Grade Ex1 for .......

1. To get 4 points , you must do the following
   
   • Create a folder ex1 on your hard disk (or floppy)

   • Copy scheme.jar and ex1.a, ex1.scm, and ex1.html into the folder ex1.

     (Do this on a Mac by holding the mouse button down on the link (don't click). A dialogue box will pop up. Specify that the files should be downloaded to the "ex1" folder as "source" (not as "text!"). On a PC, you must use Internet Explorer and push the right mouse button down on the link, the scheme.jar will download as a winzip file.

   • Change the file ex1.html so that it contains your name instead of mine and view the file in your browser. You should be able to run the assembly language program by
     • typing ex1.a into the "file" textfield,
     • hitting return (which loads the file into the textarea)
     • hitting the assemble button (which adds line numbers and replaces symbolic addresses with numbers)
     • moving the pcode window so that you can see the blue applet on the original web page,
     • hitting the "start" button (which runs the program and draws my initials on the applet)

   • Upload the folder "ex1" to your cs2a folder on your UNET web page using Fetch (for Macs) or WSFTP (for PCs). Upload the files as source, not text.
   • Add a hyperlink to the ex1.html file from your cs2a.html file.

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2. To get the next 4 points, you must
   Modify the ex1.a file so that it writes your three initials (first, middle, last) and upload it to (the ex1 folder in) your unet account. If you only have two intials, then makeup a third!

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3. Extra Credit: To get an extra 1 points, (which means winning back an extra 1/8 of your lost points), you must
   Modify ex1.a so that it uses a loop to write your initials 10 times, one below the next, and upload it to (the ex1 folder in) your unet account For example, a simple countdown loop, to count from 10 to 1 would be written as follows:

     (loadI 10 R10)        ;; first we initialize R10,R11,R12
     (loadI 1  R11)
     (loadI 0  R12)
     loop                  ;; this marks the start of the loop, it will disappear after assembly
                           ;; NOTE: there are no parentheses around "loop"
                           ;; in here we could put instruction that depend on R10
   
     (sub R10 R11 R10)     ;; here we subtract 1 from R10
     (jumpLT R12 R10 loop) ;; and as long as R10 > 0 we jump back to the loop
                           ;; NOTE: we use the name "loop" in the code, not a line number
                           ;; during assembly this is replaced with a line number
   
     (halt)                ;; otherwise we halt
   

   The other jump instructions are "jump", "jumpEQ", and "jumpLE".

How this affects your grade

Suppose your grade on the midterm was Y/33 and you lost Z/33, (so Y+Z=33). If you get X/10 points on this makeup homework, then we will add (1/2)*Z*(X/10) points to your raw course score. So if you get 10/10 your get 1/2 of your points back.

The following applet will compute your score (The source code is here)

You need a Java enabled browser to view this applet.