Address validity checks are also used in disk drives. When employed, firmware commonly compares the address on a disk pack requested in a write instruction with the set of valid disk storage locations.

Verification constraint of an IT hardware validity check

Where installed, the IT hardware validity check compares each action with the set of rules to ensure that it is indeed appropriate. Nevertheless, the limitation of an IT hardware validity check is that it will not detect an error when a valid symbolic representation is recorded improperly in place of another symbolic representation during data entry or transmission.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Boritz, Efrin J. IS Practitioners’ Views on Core Concepts of Information Integrity. Rev. ed. Ontario: University of Waterloo, 2004. 9

Gleim, Irvin N. CIA Examination Review. 3rd ed. Vol. 1. Gainesville, FL: Accounting Publications, 1989. 284

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 232-3

“View Part I of the IT Hardware Validity Checks series here”

Post Notes: “IT Hardware Validity Checks – Part IV” was originally published through Suite101.com under the title “IT Hardware Validity Checks”.

A data validity check compares characters or fields that are written or read with a set of all valid characters or fields. It is particularly useful technique with peripheral devices such as printers. For example, a printer may be limited to a certain number of characters. Consequently, if there where sixty-four characters associated with a print drum the data validity check would accept data containing any of the sixty-four characters as valid, yet would reject data representing other characters considered invalid.

Validity checking of storage location addresses

IT memory has designated storage addresses that can be accessed. CPUs utilize control units to keep track of addresses associated with the IT configuration. The address validity check compares the memory address requested with the list of valid addresses to detect an invalid request.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Boritz, Efrin J. IS Practitioners’ Views on Core Concepts of Information Integrity. Rev. ed. Ontario: University of Waterloo, 2004. 9

Gleim, Irvin N. CIA Examination Review. 3rd ed. Vol. 1. Gainesville, FL: Accounting Publications, 1989. 284

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 232-3

“View Part I of the IT Hardware Validity Checks series here”

Post Notes: “IT Hardware Validity Checks – Part III” was originally published through Suite101.com under the title “IT Hardware Validity Checks”.

Validity checking of operation codes within the Central Processing Unit (CPU)

Each computer has a recognizable instruction set (e.g. Reduced Instruction Set Computing (RISC)) with a designated code for each instruction, such as addition, subtraction, multiplication, and division. The operation validity check will signal an error condition if, during execution, a program attempts to process an invalid instruction.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Boritz, Efrin J. IS Practitioners’ Views on Core Concepts of Information Integrity. Rev. ed. Ontario: University of Waterloo, 2004. 9

Gleim, Irvin N. CIA Examination Review. 3rd ed. Vol. 1. Gainesville, FL: Accounting Publications, 1989. 284

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 232-3

“View Part I of the IT Hardware Validity Checks series here”

Post Notes: “IT Hardware Validity Checks – Part II” was originally published through Suite101.com under the title “IT Hardware Validity Checks”.

On 07/27/2012, Robert E. Davis, MBA, CISA, CICA accepted an invitation to join the ITKnowledgeExchange Advisory Board.

Determination of the validity of an IT hardware action is something a redundancy check is unable to perform. However, in conjunction with redundancy checks, validity checks provide considerable certainty that hardware processing and transfer of datum will be complete, accurate and creditable.

Sources:

Davis, Robert E. IT Auditing: Assuring Information Assets Protection. Mission Viejo, CA: Pleier Corporation, 2008. CD-ROM.

Boritz, Efrin J. IS Practitioners’ Views on Core Concepts of Information Integrity. Rev. ed. Ontario: University of Waterloo, 2004. 9

Gleim, Irvin N. CIA Examination Review. 3rd ed. Vol. 1. Gainesville, FL: Accounting Publications, 1989. 284

Watne, Donald A. and Peter B. B. Turney. Auditing EDP Systems. Englewood Cliffs, NJ: Prentice-Hall, 1984. 232-3

Post Notes: “IT Hardware Validity Checks – Part I” was originally published through Suite101.com under the title “IT Hardware Validity Checks”.

Verifying the adequacy of equipment checks

Ensuring adequate IT hardware controls is a managerial responsibility. Therefore, verification procedures should be performed to permit providing a positive assertion regarding IT hardware reliability and data integrity based, in part, on effective computer equipment checks.

The owner’s inability to provide a positive assertion regarding IT hardware deployment may be caused by lack of equipment checks that impact information integrity. Nevertheless, when inadequate equipment checks are discovered appropriate compensating and/or mitigating hardware controls should be implemented to ensure accurate and complete IT processing.

“View Part I of the IT Equipment Functionality and Integrity Checks series here”

Post Note: “IT Equipment Functionality and Integrity Checks – Part V” was originally published through Suite101.com under the title “IT Equipment Functionality and Integrity Checks”

Whereas, disc drives utilize automatic retry to facilitate successful read/write operations. Depending on the deployed hardware, the original error-free read/write may fail because the data is slightly misaligned with the designated recording track. To remediate the condition, the read/write operation will be repeated several times at different offset locations until the required action is performed or until it is clear that some other problem is at fault.

“View Part I of the IT Equipment Functionality and Integrity Checks series here”

Post Note: “IT Equipment Functionality and Integrity Checks – Part IV” was originally published through Suite101.com under the title “IT Equipment Functionality and Integrity Checks”

Lastly, data communication facilities may have cybernetic line and equipment diagnosis. This automatic diagnostic may be part of the communication hardware rather than the CPU.

Forms of automatic retry routines

Automatic retry enables electronic error correction in several situations. It is particularly valuable in the CPU, which is subject to transient error. Transient error, such as a data parity error, may occur because of temporary conditions such as static electricity or random variations in switching times. Since it is likely that such a condition will disappear on its own accord; a simple activity repeat or retry will commonly eliminate the indicted error.

“View Part I of the IT Equipment Functionality and Integrity Checks series here”

Post Note: “IT Equipment Functionality and Integrity Checks – Part III” was originally published through Suite101.com under the title “IT Equipment Functionality and Integrity Checks”

Automatic error diagnosis is utilized by several hardware configuration components. A typical application is the installation of Central Processing Unit (CPU) circuitry to diagnosis data parity errors identified in the CPU and linked storage areas. Furthermore, the CPU may have self-diagnostic capabilities to reveal defective circuitry or memory. In some instances, as a corrective measure, the CPU may be able to route operations and storage around defective configuration components.

Automatic error diagnosis is also utilized to identify faulty magnetic tape read/write heads. In this scenario, the CPU checks the read/write head during an assigned task to ensure that the current is flowing through the device. With a positive check, it is assumed that reading and writing is taking place during inspection. Conversely, with a negative check, it is assumed that reading and writing is not taking place during inspection.

“View Part I of the IT Equipment Functionality and Integrity Checks series here”

Post Note: “IT Equipment Functionality and Integrity Checks – Part II” was originally published through Suite101.com under the title “IT Equipment Functionality and Integrity Checks”

A primary hardware characteristic can be: auxiliary storage, wiring, IT board, input device, or output device. Whereby, the hardware control can be: redundant character checks, duplicate process checks, echo checks, equipment checks, and/or validity checks. Some or all of these controls can be found on two or more types of equipment within the IT infrastructure.

Common firmware programming associated with IT equipment

Regarding equipment checks, controls are generally built into circuitry to ensure that the hardware is functioning properly and, where necessary, to provide cybernetic error correction. Commonly, these capabilities are known as automatic error diagnosis and automatic retry.

Post Note: “IT Equipment Functionality and Integrity Checks – Part I” was originally published through Suite101.com under the title “IT Equipment Functionality and Integrity Checks”

Failure of a semiconductor, diode, or transistor may affect the electrical impulses utilized in the processing of data, the storage of data, and the communication of data between different equipment in the IT infrastructure. If the failure leads to a change in timing, strength, shape, or frequency of pluses; the result could be an invalid data operation, invalid data storage or transmission, or the modification or destruction of datum or program instructions.

The failure of a mechanical part is a hazard to the operation of peripheral input/output (I/O) and storage devices. Such a failure can result in an error in reading datum during an input operation or in an error in writing datum during an output operation.

“View Part I of the Computer Hardware Risks series here“

Post Note: “Computer Hardware Risks – Part II” was originally posted on my Suite101.com web page under the title “Computer Hardware Risks”