Interesting Facts, Information And Updates About World

Vectored Interrupt: In vectored interrupts, the manufacturer fixes the address of the ISR to which the program control is to be transferred. the processor automatically branches to the specific address in response to an interrupt.  • The TRAP, RST 7.5, RST 6.5 and RST 5.5 are vectored interrupts. Non-Vectored Interrupt:   But in non-vectored interrupts the interrupted device should give the address of the interrupt service routine (ISR).    • The INTR is a non-vectored interrupt. Hence when a device interrupts through INTR, it has to supply the address of ISR after receiving interrupt acknowledge signal. Maskable & Non-Maskable Interrupt: The hardware vectored interrupts are classified into maskable and non-maskable interrupts.  • TRAP is non-maskable interrupt.  • RST 7.5, RST 6.5 and RST 5.5 are maskable interrupt. Masking is preventing the interrupt from disturbing the main program. When an interrupt is masked the processor will not accept the i...

What is Interrupt and how it is generated? Interrupt is a signal send by an external device to the processor, to the processor to perform a particular task or work. In the microprocessor based system the interrupts are used for data transfer between the peripheral and the microprocessor. When a peripheral is ready for data transfer, it interrupts the processor by sending an appropriate signal to the interrupt pin of the processor. If the processor accepts the interrupt then the processor suspends its current activity and executes an interrupt service subroutine to complete the data transfer between the peripheral and processor. After executing the interrupt service routine the processor resumes its current activity. This type of data transfer scheme is called interrupt driven data transfer scheme. Types Of Interrupt: The interrupts are classified into software interrupts and hardware interrupts. • The software interrupts are program instructions. While running a program, if a software ...

  Implementation   Stage: User training, File / System conversion Key Question: What is actual operation? Are user manuals ready? Are there delays in loading files? Results: Training programs, user friendly documentation  • It is concerned with user training, site preparation and file conversion. • When system is linked to terminal or remote sites it also includes telecommunication network and network testing along with system. • During final testing user acceptance is tested followed by user training, • System testing checks the readiness and accuracy of system to access, update and retrieve  data from new files. • If testing is successful program is run with live data or else a diagnostic procedure is use to locate and correct errors. Post-Implementation and Maintenance Stage: Evaluation, maintenance and enhancements. Key Questions: is system running? Should system be modified? Results: User requirements need, satisfied user. • There is an aging process requi...

Analysis Stage: Detailed evaluation of present system data collection. Key Question: What must be done to solve the problem? what are the facts? Result: Logical model of system. Ex: Data flow diagram, data dictionary. • Analysis is a detailed study of various operations performed by a system and their relationships within and outside of the system. • One aspect of it defining the boundaries of system and determining weather or not the system should consider other related system. • Data is collected in available files during analysis. • Interview is commonly used tool in analysis. It requires special skills and sensitivity to the subject. • Training, experience and common sense are required for collecting needed information to do analysis. • After analysis analyst has firm understanding of what is to be done. Design Stage: General design specification, detailed design specification, program construction and testing (output, input, files, procedures) Key Question: In general, how mu...

  System Development And Life Cycle  An effective System Development Life Cycle (SDLC) should result in a high quality system that meets customer expectations, reaches completion within time and cost evaluations, and works effectively and efficiently in the current and planned Information Technology infrastructure. Recognition of Need  Key Question: What is the problem or opportunity? Stage: Preliminary survey / initial investigation Result: Statement of scope and objectives performance criteria. • Analyst must know what the problem is before it can be solved. • The basic for system development is to recognize of need to improve or develop an information system or a procedure. • This need leads to a preliminary survey or an initial investigation to determine that alternative system can solve the problem. • It includes looking into duplication of effort, bottlenecks, inefficient existing procedures or weather parts of existing system would be candidates for computerizat...

  De-multiplexing of AD0-AD7 of 8085 Microprocessor THE ADDRESS AND DATA BUSES: • 8085 Microprocessor have total 16 address lines and 8 data lines. • 8 signal lines A8 – A15 which are unidirectional. • The other 8 address bits are multiplexed with the 8 data bits. So, the bits AD0 – AD7 are bi-directional and serve as A0 – A7 (address bus) and D0 – D7 (data bus) at the same time. • During the execution of the instruction, these lines carry the address bits during the early part, then during the late parts of the execution, they carry the 8 data bits. In order to separate the address from the data, we can use a latch to save the value before the function of the bits changes. THE CONTROL AND STATUS SIGNALS: • There are 4 main control and status signals. 1. ALE (Address Latch Enable): This signal is a pulse that become 1 when the AD0 –AD7 lines have an address on them. It becomes 0 after that. This signal can be used to enable a latch to save the address bits from the AD lines. 2. RD ...

What is System? System is known as collection of components of a plan. System can be any software, any application or any computer related program. What is Analysis? Analysis is known as research or detail examination on any particular topic by the information or data about that topic given to us. What is Designing? Designing is the process of creating construction of system. It is reference for coding. Properties of System: Organization: It implies structure and order. It is arrangement of components that help to achieve objective. Like as, a computer system is designed around an input device, a central processing unit, an output device and one or more storage units. When linked together they work as a whole system. Interaction: It refers the manner in which each components functions with other components of system. For example, purchasing must interact with production, in computer system CPU must interact with the input device to solve the problem. Interdependence: It means the compo...