Showing papers on "Legacy mode published in 2013"

Getting Relational Database from Legacy Data-MDRE Approach

Abstract: The previous management information systems turning on traditional mainframe environment are often written in COBOL and store their data in files; they are usually large and complex and known as legacy systems. These legacy systems need to be maintained and evolved due to several causes, including correction of anomalies, requirements change, management rules change, new reorganization, etc. But, the maintenance of legacy systems becomes over years extremely complex and highly expensive, In this case, a new or an improved system must replace the previous one. However, replacing those systems completely from scratch is also very expensive and it represents a huge risk. Nevertheless, they should be evolved by profiting from the valuable knowledge embedded in them. This paper proposes a reverse engineering process based on Model Driven engineering that presents a solution to provide a normalized relational database which includes the integrity constraints extracted from legacy data. A CASE tool CETL: (COBOL Extract Transform Load) is developed to support the proposal. Keywords: legacy data, reverse engineering, model driven engineering, COBOL metamodel, domain class diagram, relational database

I/O and Interrupt Handling in the Microthreaded Mode

Abstract: An I/O (Input/Output) subsystem is provided by standard peripherals connected via the AMBA bus to the UTLEON3 processor. From the user perspective the peripherals are available in the non-cacheable address space. In the microthreaded mode a common peripheral access is provided in the same manner as in the legacy mode; the UTLEON3 processor does not require any extra modifications. The only difference is in interrupt (or trap) handling. The function of the peripherals in the legacy mode is described in the GRLIB IP Core Users Manual (see 5. In the UTLEON3 processor interrupts are viewed as traps invoked by a peripheral. From the hardware point of view interrupts are handled by the multiprocessor interrupt controller (IRQMP 5 in the legacy mode. The interrupt scheme is depicted in Fig.9.1.

Design and Implementation of IEEE 1394 Signaling Rate Converter

Abstract: This paper mainly expounds the design and implementation of IEEE 1394 signaling rate converter, and emphatically describes the system structure design, basic hardware design, and function realization of IEEE 1394 signaling rate converter. IEEE 1394 signaling rate converter mainly realizes the function of signaling rate conversion in legacy mode, signaling rate conversion in Beta mode, mode change between legacy and Beta, and 1394 bus relay.

A framework - migrating legacy systems

Abstract: In recent past, several organizations have shown great amount of interest in enhancing their business know-how and gaining a reputation among the corporate world, so that they may remain to a larger extent in ever increasing business and may achieve their goals at large (VA12). IT industries are often having confrontation with ever changing business. Besides, several corporate still depend upon the older versions, referred to as legacy systems like software developed in the past over programming languages like C, COBOL, PASCAL, FORTRAN etc (S06). Legacy systems have numerous shortcomings as they have been developed on older technologies, so they can't be migrated to newer environment easily (M10). In spite of the above mentioned aspects, still legacy systems are usable at large because of the storage of complete business logic and implementation in them. Also, these systems can't be overridden simply because the information existing in them is of vital importance to an organization. Also, in order to make these systems operational, the amount of effort in relation to availability of suitable documentation, trained professional and know-how is not in existence at length (ZYZZ10). Thus, a model has been studied and based on it; a new framework has been developed, by using reengineering technique, so as to migrate legacy systems.