Computer Science 270

Computer Organization


MIPS Drawings

In order to come to grips with the intricacies of data flow and control in the MIPS processor, it's useful to trace out the paths taken by data elements and the routes taken by control signals on schematic drawings of the processors involved. The most useful illustrations from chapter 5 of COD for these purposes are the following (pdf versions of the publisher's Postscript files):

Print out a few copies of these illustrations and use highlighters and colored pens to produce illustrations to accompany your solutions to the assigned exercises from chapters 5 and 6 of COD. Go over to the library and use the scanners in the ATC Computer Lab to scan your illustrations into jpeg files. Write up a web page containing the text of your solutions and the accompanying jpeg illlustrations. The following sections contain further indications on how to accomplish this, as well as a selection of results submitted by students in this class.

Scanning MIPS Processor Drawings with Adobe Photoshop

1. Go into the library and downstairs to the ATC Computer Lab. At the far end of the room is a row of large two-toned gray Macs with UMAX Astra scanners attached to them. Log into one of those computers.

2. Place the page to be scanned on the flatbed of the scanner and close the lid.

3. Go to the Apple Menu and choose Adobe Photoshop 6.0. Once Photoshop launches and settles down, choose File:Import:UMAX Vistascan. Use Beginner settings if you are not yet used to using Photoshop. Check that you are asking for a "Color, RGB" image with "300 dpi" scanning quality. Click on Preview to get a low resolution image of the target document.

4. Using the Beginner settings, select the "new view frame tool" (dashed rectangle with a plus sign inside of it) to select the region of the target page that you wish to scan. This places a green rectangle around the selected region. Click on Scan. Be patient.

5. The scanned image appears in a Photoshop window. Select "Rotate 90 degrees CW" to rotate the image into its natural position. Select File:Save:Format Photoshop (creating a .psd file, an official "Photoshop Document") to save the result as a (rather large) Photoshop document. This provides a high-resolution scan as a backup to start from in case you decide to go back and and choose different Photoshop image manipulations.

6. Ths is the time to play with some of the image manipulation capabilities of Photoshop. Choose Filter:Sharpen:Sharpen to get clearer lines and labels. Try Image:Image Size:Width 700 pixels to generate an image appropriate for many computer screens. Experts say its's easier to work with pixels for these purposes than to try to work with inches.

7. Select File:Save for Web, and choose the image quality you deem appropriate for your purposes. Better quality pictures generally require larger files. In the righthand panel you might begin by choosing jpeg and high resolution. In the image size panel, select about 700 pixels if it is not set at that already. Select the panel containing the image quality you prefer and click on OK. Use meaningful names to label your images, perhaps something like "COD_5.5_cp.jpg" for Chris Parrish's solution to problem 5.5 of the COD text.

8. Test the outcome by opening Internet Explorer on the newly created image. A good result is clearly readable and fits nicely on the web browser page. Create several images using different settings to get a feel for the possibilities.

9. Create an html web page to display the text of your solutions and their associated images.


Sample Web Page

MIPS add and addi


cparrish@sewanee.edu