Computer Organization

1
Computer Organization

• Project 4
• Prof. Jerry Breecher
• CSCI 140
• Spring 2003

2
What You Will Do In This Lab.

• The purpose of this lab is to take the next steps
  in writing a more complex program.
• You are working toward writing a program that can
  take in the following input
• ADQltwsgtstring1ltwsgt.ltwsgtstringN
• Where
• ADQ means Sort in Ascending order, Descending
  order or Quit.
• ltwsgt whitespace space or tab.
• There is a considerable amount of work to do
  here, and so it makes sense to divide this into
  smaller pieces.
• The piece you will be working on this week is
  parsing an arbitrary input string.

3
What You Will Do In This Lab.

• So the interface for the next part of the
  assignment will look like this
• Delimiter(s) CEF
• String To Parse Now iCeciclEs Descend From thE
  sky
• Result
• Now i
• ecicl
• s Descend
• rom th
• sky
• Delimiter(s)

The string of characters between each of the
delimiters is printed out.
4
What You Will Do In This Lab.

• Groundrules
• Credit for Projects
• Is based on deliverables.
• There will be no test plan for this project.
• You will be expected to do a Show and Tell one
  week after the lab is assigned.
• You will also be expected to turn in your
  assignment, placing it in the CS140 submissions
  directory. To do this, name your completed code
  as proj4.s, and then from the directory in which
  the code currently resides, type the following
• jbreecher/turnin.pl 140 proj4.s

5
What You Will Do In This Lab.

• look_for_delimiters
• Writing the interfaces and specs for routines
  goes a long way toward breaking up the project.
  One way to do this is to define the routine
  look_for_delimiters with the following interface
• look_for_delimiters
• Inputs
• a0 - contains the address of the
  delimiter string.
• a1 - contains the address of the start
  of the string to be parsed.
• The delimiter string has the following
  properties
• lt0 or more characters that are
  delimitersgtltThe NL chargtlt0gt
• The string to be parsed has the following
  properties
• lt0 or more characters, some of which
  MAY be delimitersgtltThe NL chargtlt0gt

6
What You Will Do In This Lab.

• look_for_delimiters
• Heres the continuation of the interface spec.
• Outputs
• a0 (unmodified) - contains the address
  of the delimiter string.
• a1 (unmodified) - contains the address
  of the start of the string that was parsed.
• v0 - A pointer to the location in the
  parsed string where a delimiter was found.
• v1 The delimiter character that was
  found.

7
A Test Plan

• Here are some possible inputs that you can check
  for. I have attempted to give you some
  interesting and unusual conditions.