Advances in software engineering and programming languages have had an impact on productivity, time to market, comprehension, maintenance, and evolution of software. Low-level systems have been largely overlooked in this arena, not only because of their complexities, but also the "bare bones'" culture of this domain. This dissertation investigates the program comprehension needs of two stakeholder groups using different assembly languages: a mainframe development group and a malware analysis group. Exploratory interviews and surveys suggest that the groups' needs may be similar at a high-level. However, a detailed study involving requirements elicitation and case studies, reveals that the truth is much more complicated. As a proof of concept, we have created the AVA (Assembly Visualization and Analysis) framework, which is independent of the underlying assembly language. Despite this independence, tools within AVA could not be applied with equal efficacy, even just within these two groups. This dissertation shows that there exist fundamental differences not only in the highly-specialized nature of each group's work, but also in the assembly languages themselves. This reality necessitates a disjoint set of tools that cannot be consolidated into a universally applicable framework. / Graduate / 0984 / jebaldwin@gmail.com

Advances in software engineering and programming languages have had an impact on productivity, time to market, comprehension, maintenance, and evolution of software. Low-level systems have been largely overlooked in this arena, not only because of their complexities, but also the "bare bones'" culture of this domain. This dissertation investigates the program comprehension needs of two stakeholder groups using different assembly languages: a mainframe development group and a malware analysis group. Exploratory interviews and surveys suggest that the groups' needs may be similar at a high-level. However, a detailed study involving requirements elicitation and case studies, reveals that the truth is much more complicated. As a proof of concept, we have created the AVA (Assembly Visualization and Analysis) framework, which is independent of the underlying assembly language. Despite this independence, tools within AVA could not be applied with equal efficacy, even just within these two groups. This dissertation shows that there exist fundamental differences not only in the highly-specialized nature of each group's work, but also in the assembly languages themselves. This reality necessitates a disjoint set of tools that cannot be consolidated into a universally applicable framework. / Graduate / 0984 / jebaldwin@gmail.com

<p> Many industries have legacy software systems which are definitely important to them but are however, difficult to maintain due to a lack of understanding of those systems. This occurs as a result of inadequate or inconsistent documentation. Although the costs of redesigning the system may be large, some organizations still plan to reverse engineer the software specification documents from the code to alleviate a large burden from such endeavour. This thesis provides an incremental and modular approach to create a process and tools to extract the semantics of legacy assembly code.</p> <p> Our techniques consist of static analysis and symbolic interpretation in order to reverse engineer the semantics of legacy software. We examine the case of IBM-1800 programs in detail. From the abstract model of the operational semantics of IBM-1800, we simultaneously obtain an emulator and a symbolic analysis process. Augmented with control flow information, we can use the symbolic analysis to provide complete semantics for the code sequences of interest. We can also generate Data Flow Graphs to depict the flow of data in those code segments. The whole process of extracting semantic information from the assembler codes is fully automated with only a little human intervention at the initial step.</p> <p> We use Haskell as our implementation language and its important features help us to create modular and well structured software. The literate programming documentation style in this thesis increases the readability and consistency of the implementation's documentation.</p> <p> The process and the associated tools created in this thesis are used in a large reverse engineering project, which has a goal to extract requirements specification from legacy assembly code. This project is funded jointly by Ontario Power Generation (OPG) and CITO (Communications and Information Technology Ontario).</p> / Thesis / Master of Applied Science (MASc)

Magister Scientiae - MSc / Computer architecture and assembly language programming microprocessor execution are basic courses taught in every computer science department. Generally, however, students have difficulties in mastering many of the concepts in the courses, particularly students whose first language is not English. In addition to their difficulties in understanding the purpose of given instructions, students struggle to mentally visualize the data movement, control and processing operations. To address this problem, this research proposed a graphical visualization approach and investigated the visual illustrations of such concepts and instruction execution by implementing a graphical visualization simulator as a teaching aid. The graphical simulator developed during the course of this research was applied in a computer architecture course at Kabul University, Afghanistan. Results obtained from student evaluation of the simulator show significant levels of success using the visual simulation teaching aid. The results showed that improved learning was achieved, suggesting that this approach could be useful in other computer science departments in Afghanistan, and elsewhere where similar challenges are experienced. / South Africa

The master thesis discusses the design of an emulator of a CPU architecture instruction set aimed at assembly languages course. While most of nowadays emulators are architecture specific, the emulator proposed in master thesis aims at education and better understanding of assembly languages. The emulator is not limited to a single CPU, but it easily allows defining a purpose-specific architecture and instruction set in order to perform operations upon it and to display its current state.

The Altair 680b Cross-Assembler is a program written in the Nova Assembly Language. It can be used to assemble Altair 680b assembly language programs. The object code can be punched on paper-tape for execution on the Altair 680b microcomputer. This report describes the design and working of the Cross-Assembler. A program listing and a few sample runs are also included. / Thesis / Master of Science (MSc)

This thesis describes a software implementation of the IEEE Floating-Point Standard (IEEE Task P754), which is believed to be an effective system for reliable, accurate computer arithmetic. The standard is implemented as a set of procedures written in Motorola 6809 assembly language. Source listings of the procedures are contained in appendices.

This thesis describes a set of computer program control structures which permits the application of certain structured programming techniques to the IBM/360 assembly language (ALC). The control structures are implemented by programmerdefined instructions known as macros. A history of computer software is presented, providing a basis for the emergence of structured programming. A survey of the major concepts of structured programming with special attention to control structures and their significance to structured programming follows. The macros developed in this study include DO, ENDDO, LEAVE, CASE, and ENDCASE. They provide a looping control structure, a loop-escape construct, and a selective control structure. Examples of usage are given.

The problem with which this investigation is concerned is an analysis of errors in looping and assignment made by novice assembly language computer programmers. This analysis is made after subjects write three computer programs. The verbal definition of the problem for each program specifies, without naming, either a for, while, or repeat looping structure. The purposes of the study are the following; to determine whether using the appropriate looping structure is related to writing a correct program; to determine the incidence of assignment errors in incorrect programs; to determine the degree of relationship between mathematical aptitude, and the type of assignment errors made; to determine the degree of relationship between use of the appropriate looping structure and mathematical, verbal, and scholastic aptitude; to determine the degree of relationship between gender and use of the appropriate looping structure, and to determine the degree of relationship between gender and the number of assignment errors.

<p>Fully homomorphic encryption allows computations to be made on encrypted data without decryption, while preserving data integrity. This feature is desirable in a variety of applications such as banking, search engine and database querying, and some cloud computing services. Despite not knowing the plaintext content of the data, a remote server performing the computation would still be aware of the functions being applied to the data. To address the issue, this thesis proposes a method of encrypting circuits and executing encrypted instructions, by combining fully homomorphic encryption and digital logic theory. We use the classic RISC Archtecture as a foundation of our work, and the result of our algorithm is essentially an encrypted programming language, where a remote server is capable of executing program code that was written and encrypted by a local client.</p> / Master of Science (MS)