Human Services Technology by Dick Schoech, Published by Haworth Press

Chapter 9: Hardware and Software Influences on IT Development

Web sites Additional review & discussion questions Exercises Additional readings

Web Sites relevant to sections of this chapter

HW basics HW functions HW components SW basics Implications
Site Relevance

Section 1:  Hardware basics



Section 2: Hardware functions



Section 3: Hardware components



Section 4: Software basics



Section 5:  Implications for system design and development


Additional Review and Discussion Questions

  1. none


Exercise 1: Using Computer Hardware

            At this point, hands-on exercises with a computer are highly recommended.  One approach is to use tutorial computer programs which explain the computer and its components.  Another is to connect to the Internet and search for sites that provide hardware and software tutorials.

Exercise 2.  Creating A “Human” Computer-Part II

This is the second in the series of exercises begun in Chapter 2.  If this exercise is done as a class project, assign one of the following computer components to each class member.  Use pieces of string to interconnect the components.  Use red string for the flow of electricity and white string for the electronic flow of data.  After the components have been connected, members describe the direction of electricity and information flow and what each component does from the time the electrical power is turned on until a program has been run.  The operation of each component is described below.  Students may be assigned components the week before so they can find information about and possibly a picture of the component.

Description of Component Operation

            Power Supply: The power supply accepts standard electrical current from a wall plug and converts it into the variety of voltages and amperes currents used inside the computer.

ROM: Read Only Memory (ROM) chips store instructions and data that are etched in the chip by the computer manufacturer.  Once the instructions and data are etched in ROM they are permanently available and are not erased when electrical power is turned off.  The instructions stored in ROM allow the computer to determine which components are available and to perform checks to be sure all are operating properly.  They also instruct the computer to look for the operating system and load it into RAM.

RAM: Random access memory (RAM) chips provide memory used to store instructions and data

needed to operate the computer and run programs.  The information stored in RAM is available only while electrical power is turned on to the computer.  It is erased when power is lost or turned off.

CPU: The CPU is the “brain” of the computer system.  It performs several kinds of operation.  It stores and retrieves information from memory, it sends and receives information from peripheral devices, it performs arithmetical and logical operations, and it keeps track of the steps involved in performing an operation.  When the computer is first turned on, the CPU first reads instructions from one or more ROM chips so it can check the status of the components.  After verifying that the components are working, the CPU looks for the first program it is to perform and loads it into RAM.  Most computers run a program called an operating system which is stored on a hard or floppy disk.  The operating system controls the operation of the peripheral devices and allows other programs to be run.

Hard Disk Drive: The hard disk drive reads and writes information on a hard disk.  The information may be instructions or data.

            Hard Disk Controller: The hard disk is managed by the hard disk controller which processes control signals and information between the CPU and the drive. 

Floppy Disk: The floppy disk provides inexpensive permanent information storage so that the information can be used again.

Floppy Disk Drive: The floppy disk drive reads and writes information on a floppy disk.  The information may be instructions or data.

            Floppy Disk Controller: The floppy disk drive is managed by the floppy disk controller which processes control signals and information between the CPU and the drive. 

Keyboard: The keyboard translates human touches into electronic signals that are transmitted to the video display terminal and the CPU.

            Monitor: The monitor has a screen (sometimes called a CRT).  The CPU sends information to the monitor and receives information from the keyboard.  The user reads the monitor to control the operation of the computer.

            Monitor Controller: The monitor controller manages the processing of video control signals and information between the CPU and the monitor. 

Printer: The printer transfers information such as reports, text, and graphics

from electronic form to paper and ink form.

            Printer Controller: The printer controller manages the control signals and information sent from the CPU to the printer.

            Operator: The operator is the computer user.  The operator turns on electrical power to the computer, selects programs to run, and gives the commands to run them.  The operator interacts with the computer using the keyboard and monitor, loads floppy disks into the floppy disk drive, loads paper and ribbons into the printer, and uses printouts.

            Other: If additional components are needed, the CPU can be divided into the control unit, the arithmetic unit, the logic unit, and registers.  Also, a hard disk and hard disk controller can be added.

Exercise 3.  Collecting Pictures Of Input/Output Devices

            Many input and output devices exist which are beyond the scope of this text.  Examine newspapers and other publications for pictures of computer input and output devices.  Pass these pictures around the class along with a description and list of specifications for each device.

Exercise 4: Selecting a computing system for a human service agency

Visit two computer stores and shop for the hardware and software to meet DBMS needs defined for Community Counseling, Inc. as described in Exercise 2 of Chapter 6.  When asked about the cost you can pay for a system, indicate that cost is currently a secondary criterion in your decision.  Jot down and bring to class the results of the two visits.  Be prepared to discuss the following with the class:

  1. Description and cost of all hardware each store recommended.

  2. Description and cost of all application each store recommended.

  3. How well your needs would be met by the systems.

  4. Your reaction to the salesperson and the store.  Would you buy from the store?

  5. Ask the salesperson if s/he knows of any human service application which might help CCI provide its services (accounting, scheduling, and direct service delivery, for example).

  6. While at the computer store, ask for a good pamphlet or book to introduce you to hardware and application.

Discuss with the class your impression of available literature, the approach used by the literature to introduce IT, and the appropriateness of the literature for human service personnel.

Exercise 3: Writing a Computer Program

            This exercise illustrates the difficulty of writing detailed instructions for a machine.  Divide into work groups to write a program to direct a robot (class instructor or class member) to make a mark on the chalk board. The robot can rotate (change direction), move laterally (as though walking), and move vertically (as though raising a hand). The robot is illustrated in Figure 3.2. The command set is shown below. The information shown enclosed by parentheses must follow a command. The options that the information enclosed by parentheses may take are shown between the brackets {/}.

Robot command set

TURN (direction) {CLOCKWISE, COUNTER CLOCKWISE} (distance)


MOVE (direction) {FORWARD, BACKWARD, LEFT, RIGHT} (distance)


RAISE (distance) {FEET, INCHES}


In addition to these commands it is possible to use the structured programming

techniques such as IF . . . THEN . . . ELSE and DO

. . . WHILE. Relational expressions such as LESS THAN and EQUAL TO and logical expressions such as AND and OR may also be used.

Construct the program to make the robot write a + on the board. For ease of

writing, instructions should be numbered as shown below.

10 MOVE (Forward) (3 feet)

20 TURN (clockwise) (90 degrees)

30 SENSE (distance from) (wall)

40 WHILE distance from wall is greater than 1

50 MOVE (forward) (one inch)

60 etc.

            The winning group is the one which instructs the robot to make the mark on the board with the least number of lines of code and without damaging the robot. After completing the exercise, answer the following questions.

  1. What marks can the robot make?

  2. Can the robot be programmed to draw a circle?

Additional Reading

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