Dispute Resolution
Computer Expert Evidence

Place County Court                                                                                       Case Number


Expert Witness's Explanatory Report




           Copyright Cliff Dilloway 1997. Author's moral rights are asserted.

Place County Court                                                                                       Case Number


Computer Expert Witness's Explanatory Report

1. Introduction

This Report has been prepared by Clifford Charles Dilloway on instructions from the Plaintiff. Clifford Charles Dilloway is a Chartered Engineer, a Chartered Information Systems Engineer, being a Fellow of The British Computer Society, a Chartered Management Accountant being a Fellow of the Chartered Institute of Management Accountants, a Registered Arbitrator being a Fellow of the Chartered Institute of Arbitrators and a Fellow of the Academy of Experts. He has long experience of using computers.


2. Instructions

2.1     I am instructed by P that a first hearing in this matter took place on 00 March 199X and was adjourned until 00 May 199X. P has supplied me with copies of the documents before the court on 00 March 199X and his own notes of what took place at the hearing.

2.2     I am instructed that the issues and the technical background did not come out clearly at the 00 March 199X hearing and that I should produce a report expressing my opinions on the various matters brought up. I have not examined the computer the subject of the dispute, partly to save costs but mainly as I understand that it is now in good working order and a technical examination would not add to the evidence before the court.

2.3     I am making a purely nominal charge to P for the production of this report.


3. The Computer

3.1     The computer is an IBM compatible personal computer or, as such machines are now universally described, a PC. IBM (the largest computer company in the world) introduced the Personal Computer in 1981. The IBM Personal Computer and the Operating Systems produced by Microsoft have become the standard that has to be conformed to for a computer to be a PC. This is a defacto standard that has constantly been developed by IBM, Microsoft, their original Operating System Supplier, and Intel, the supplier of the computer on a chip on which the machines are all based. This last sentence is now explained in greater detail.

3.2     When IBM put their name on the product we now call a PC it was instantly accepted by the customers in the market place and the suppliers of software to that market place as a standard that would evolve and develop. It was the trust that IBM's name engendered that enabled the PC to become the standard it now is.

3.3      The word "computer" when used on its own is usually referring to the "hardware". Computer hardware is readily defined as anything that consumes electricity.

3.4      There is only one thing that computer hardware can do and that is to obey a computer program. Computer programs and any other part of the totality of a computer system other than the computer hardware is computer software.

3.5     As the only thing that computer hardware can do is run software programs there has to be a standard computer program that interacts with the computer user and which he looks on as being the "computer". These standard computer programs are called the "operating system". The dominant supplier of operating systems is Microsoft (of Bill Gates fame) and the operating systems they supply are called MS-DOS, Windows, Windows 95 or Windows NT. There has to be and is close collaboration between manufacturers of PC computer hardware and Microsoft to ensure that when the operating system software runs on PC computer hardware no difficulties arise. If there are difficulties the almost invariable result is not wrong results but the computer program failing to continue operating. If a computer software program fails to continue to operate the computer hardware is not doing the only thing it is capable of - running computer software programs - and this condition is described in the evidence by saying the computer "locks-up". P also uses the expression "crashing" which has the same meaning as "locked up". No physical impact is implied. The way out of a lock-up is to turn the computer off using the main power on/off switch, count up to ten and then turn the computer on again. Turning the computer on again will cause a fresh copy of the computer software programs to be used and this may be expected to control the computer hardware until the program terminates in the normal course, or the computer locks up again because the computer software program has again failed to continue to operate. P does complain of repeated crashing.

3.6     The meaning of the expression "computer software program failing to continue to operate" is now explained. A computer software program consists of a very large number of individual program instructions that are carried out one after the other. Each individual program instruction has to be capable of causing the computer hardware to do something and then cause a correct hand-on to the next computer program instruction. Several millions of instructions will be preformed per second. What was wrong with the computer in this case to cause it to lock up is dealt with by the factual technical evidence from the independent computer repair company's letter dated 00 October 199X so is not discussed here. What can be said is that timing throughout the computer is by its internal clock and coordination are important factors. When computer hardware is locked up it is stuck on a computer program instruction as either

    It is when either of these occur that the computer user has to resort to turning the computer's electrical power off and on again.

3.7     The part played by Intel, the designer and manufacturer of the computer on a chip used in the IBM Personal Computer or PC is now discussed. The computer on a chip is described in the evidence as a CPU which stands for "central processing unit" and that is no more than a term meaning "computer". Since 1981 Intel has produced a series of faster and more versatile computers on a chip. In general higher numbers are used to indicate more power and speed. Thus P was having his computer on a chip converted from a 386 to a 486 to obtain more versatility. Numbers such as 266 and 280 quoted in the evidence refer to the speed at which the computer on a chip runs, a higher number indicating more program software instructions being performed per second.


4. The parts of a PC

4.1     The dispute revolves round what may be called the "innards" of the computer so no mention is made here of the monitor which consists of a cathode ray tube in a visual display unit (it looks like a television screen) or the keyboard or printer.

4.2     The computer on a chip manufactured by Intel is mounted on a printed circuit board fitted inside the computer. The main printed circuit board is called a motherboard. The computer on a chip has a number of pins protruding for its electrical connections and it is mounted on the motherboard by the pins being inserted in the appropriate sockets. Over the years PC designers have been able to reduce the number of components that need to be used (more sophisticated chips have become available) and the number of printed circuit boards required inside a PC has been reduced. This process is reflected in cost terms where a fairly constant price of GBP1,000 to GBP1,500 has purchased increasingly powerful PCs.

4.3     Reference is made in the evidence to a I/O Board. I/O stands for Input/Output. This is a separate printed circuit board in the PC on which the chips controlling the keyboard and printer are located.


5. Explanations of technical terms

5.1     Throughout the documents provided to me (and doubtless in the oral evidence of the technical specialists) technical terms have been used. The technical terms found in the documents are classified under a number of headings and explained here.

5.2      Computer hardware (ie all those parts that consume electrical power).

5.21     'OPTI' chipset. The evolution of the power of the PC has been assisted by "third party" manufacturers who have produced computer chips that are better able to carry out some of the functions of a PC. The 'OPTI' chipset is one such well recognised advance.

5.22     4MB 70NS 72 pin SIMM. A chip that is all computer memory. The elements of it are

         4MB - four Megabytes. Mega means million and Byte is the smallest recognisable storage unit.

         70NS. Seventy nanoseconds. The speed of the computer memory (expressed as the timing of a cycle).
        A nanosecond is a thousand millionth of a second.

         72 pin. The number of wires (pins) protruding from the memory unit for electrical connections.

         SIMM. Single Inline Memory Module. The memory chip itself is encapsulated by (sealed inside) a plastic
         casing with the pins protruding to make a memory module. The pins may be plugged into sockets on a printed
         circuit motherboard.

5.23         Printed circuit board. A flat board of insulation material with electrical conducting strips laid down on both sides as "wires". Holes in the board permit inter connection between the printed circuit "wires" on both sides of the board. Sets of holes or sockets permit the mounting of computer chips and other electronic components on a printed circuit board. A motherboard is a printed circuit board. At the end of the printed circuit boards are a number of larger areas of electrical conductive material that forms a "plug" that is inserted into an "edge connector" on the "bus" that is the permanent wiring in the computer connecting the major components together.

5.24         Ram board. Ram stands for Random Access Memory or a computer memory module as viewed from the viewpoint of a computer program that utilises the memory. The "Board" is a printed circuit board. A ram board is therefore a place and means of putting extra memory in a PC.

5.25         Multi I/O card hard disk controller circuit. The hard disk is the large capacity information storage device on a PC. The controller circuit controls the speed of the disk's rotation and the access mechanisms that control the reading and writing of information on the storage device. The multi I/O indicates the other functions of this printed circuit card (ie board) which have been brought together as part of the process of reducing the number of components in a PC.

5.26         Diagnostic board. A printed circuit board used by electronic engineers to test out and identify faults in other components of a PC.

5.27          Heatsink and fan. The laws of physics dictate that all the electrical power consumed by computer hardware finishes up as heat that has to be dissipated. A heatsink conducts heat away from the power using components to a series of fins. In this way it is working much like a central heating radiator. The fan blows air over the fins, assisting in the dissipation of the heat. A computer chip will malfunction if it is allowed to overheat.


5.3 Software.

Firstly the applications software that P used to do the things he wanted to do on his computer.

5.31          Word. A wordprocessing system.

5.32         Excell. A database system. Provides a management structure so that information can be arranged in an organised and usable manner.

5.33         Office Professional. A combination of word processing database and spreadsheet software. A spreadsheet is a calculating method based on rows and columns with a means of specifying the calculations to be performed on the data contained in the boxes thus formed.

5.34         MS Applications. All of the above. MS stands for Microsoft of operating system and Bill Gates fame.

5.4         Other software. Secondly the software P had to use his computer.

5.41         Windows for Workgroups 3.11. An operating system. Operating systems are described in the earlier text. To a computer user the operating system is what he sees as "the computer".

5.42         Windows registry. A term from an operating system called Windows 95 which I have not noticed being mentioned. The registry is the place in the operating system that keeps track of where things are stored in the computer.

5.43         Screen Saver. If a cathode ray tube constantly displays the same information marks will appear on the screen. This phenomenon is noticeable on cash card dispensers. A screen saver will project a constantly moving image on the screen while the computer is otherwise idle to avoid the creation of marks.

5.44         Program Manager. An element of Windows for Workgroups 3.11 that performs services needed to look after and provide access to the computer software programs used on the computer.

5.45         ROM BASIC. Basic is a programming language that is used to express the solutions to problems in a manner that may be obeyed by the computer hardware. ROM stands for "read only memory" which is a separate part of the computer memory that permanently holds a computer program that converts the solution to a problem, as expressed by the computer user in the Basic programming language, to the form of computer program that is obeyed by the computer.

5.46         CMOS stands for Complementary Metal Oxide Semiconductor, which is a form of computer memory storage which has no relevance to the meaning of CMOS in the context in which it is usually used. The expression CMOS is conventionally used to refer to a type of computer program setting held in that computer's CMOS memory storage and which is now explained. The PC uses an Intel computer chip and a Microsoft operating system, this is explained in the earlier text. There have been many versions and speeds for the Intel computer chip and many types of hardware devices incorporated into or attached to the computer hardware of which they form part. There have been many versions of the Microsoft operating systems. So that the computer chips, hardware devices and operating system can interwork they have to know various things about one another. The information about these things is contained in the CMOS memory. It comes naturally to talk of the CMOS set- up and setting up the information in the CMOS is a technically demanding and not very well understood task.

5.47         AUTOEXEC.BAT & CONFIG.SYS. When the electrical power to a computer is turned off all the programs held in the main computer memory are lost. When the electrical power is turned on the computer goes through a process of loading computer programs, particularly the operating system, to bring the computer to the normal operating state favoured by the user. AUTOEXEC.BAT & CONFIG.SYS I would regard as programs that contain information that is used to bring the computer to the normal operating state favoured by the user.

5.48         Norton Utilities. A set of program commercially available to computer users for diagnosing the state of and faults on computer hardware and software.


5.5 Actions

5.51         Reset or Rebooting. The process of turning a computer off, counting up to ten and turning the computer on again. A fresh start is made. A similar result can be obtained by depressing three particular keys on the keyboard.

5.52         Return to base. A trade description of a warranty service provided whereby the computer user has to return his computer hardware to his suppliers' premises in the event that warranty service is required.

5.53         Electro Static Discharge explained in the relevant context. The human body is capable of holding a high voltage electrical charge. This may be noticed in dry weather just as one's hand comes into contact with a car door handle. The charge jumps the final gap and there is a snap and sting as the charge is discharged. If instead of a motor car a computer component is involved the discharge can cause damage. For this reason computer engineers wear electrically conducting wrist straps leading to a good earth when handling computer components.

5.54         External Power Surge. The nominal electrical power supply of 230 volts is subject to occasional "spikes" of very high voltage. Although the computer hardware contains protective circuits against such spikes they can get through to affect the about five volts used by computer components. Lift motors are a notorious source of spikes on mains power.

5.55         Hyundai is the name of a computer manufacturer.


6. Note.

This Explanatory Report consists of technical explanations provided by the Expert Witness. The Expert Witness's opinions are expressed in a more concise "Expert Witness's Summary Report" bound separately.

Copyright Cliff Dilloway 1997. Moral rights are asserted.