Tuesday, 6 September 2011

Data Transfer Instruction

What is the data transfer instruction? Give example.

Data transfer instructions move data between registers or between memory and registers. For example:

String Forms:

movsb ;move string byte by byte

movsw ;move string word by word

EXAMPLE:

Movsb es, ds ;Copies 8 bits at DS:SI to ES:DI

New String Form (386+):

movzx ;move string with zero extended

movsx ;move string with sign extended

EXAMPLE:

movsx cx, al ;cl get al

movzx cx,al ;cl gets al

Wednesday, 10 August 2011

London Riots 2011

The normal protests against the merciless killing of an African 29 year old boy Mark by the London police unbelievably turned into the violence and looting on the streets of London which rise up to their highest all across the United Kingdom in the period of just four nights.

This is for the first time in the decades of the London history that such looting and violence is seen by the youth of England on the streets of London. The uncontrollable riots started in the Nottingham then later on the same night spread to the south part of the London city and then to the eastern and the northern parts of the London. The most affected cities from this looting and violence are noticeably Birmingham, Peckham, Ealing, Manchester, Liverpool, Clapham and many other smaller areas in the Central London like Piccadilly Gardens and the popular Asian people’s place, the green street.

When the riots broke out, the British Prime Minister Mr. David Cameron and the London Mayor Mr. Boris Johnson was on the holidays, both the personalities were called back to London as soon as possible and understanding their duties towards their country they returned to London the very same night.

In the morning of the next day i.e. Tuesday, the 9th of August 2011, the British prime minister called an emergency meeting of the COBR - A (Cabinet Office Briefing Room A) and it was decided in the meeting to appoint 10,000 more policemen on the streets of London which were 6,000 the last night i.e. the Monday night, which helped in the arresting of more than 1,000 of the rioters from all over the London.

So in the result of putting a very large number of the policemen on the streets of London that night, the night went very calm as compared to the night before in which the major shops were looted, cars and houses were set on fire and there were clouds of smoke everywhere.

Now today, the policemen have given the charge to do whatever needed to put the law and order back in to the streets of London and they will be using water cannons too (if needed). As many of the Londoners have lost their houses, their businesses which they were running for decades in the calm, organized and beautiful city of London, the prime minister specially visited the affected areas to show condolences with the people in fear of losing their properties and families.

It is said that great things happen when people join together is so true in this case as the violence was started from the social networking websites which resulted in the ban on the blackberry messaging services across the London. In contrast to this, today, the social networking websites helped people to get together and come out to the streets of the London for the cleanup mission which was started by none other than the British prime minister himself.

These riots in London, after 4 days, are still the head news in most parts of the world because of the London’s peaceful and “freedom of everything” image over the world.

We hope that there will be peace again.

Long Live London.

Further: You can have a glimpse on the riots in London on this link: http://freearticlewriters.blogspot.com/2011/08/london-city-riots-2011-as-seen-in.html

London city riots 2011 as seen in pictures …












the CCTV images of the violence and the failure of the London metropolitan police (London Met) against the rioters.















the beautiful view of the Trafalgar square pre riots.















shops and buildings set on fire in Tottenham.















The London Trafalgar square, post riot.










London on fire in the silent, dark and fearful nights with lots of smoke clouds.















it is said by the psychiatrists that the parent less children in United Kingdom (UK) are now becoming outrageous over time and they have a very very violent behavior towards things.














a van after being the toy for rioters in the London city.















as the 16,000 policemen were put on the streets of London.













popular and beautiful buses of London specially called double deckers.


We hope that there will be peace again.

Long Live London.

Further: Read the full story of the riots in London on this link: http://freearticlewriters.blogspot.com/2011/08/london-riots-2011.html



Friday, 17 June 2011

polling in 8085 microprocessor

What do you mean by polling in 8085.

When the microprocessor receives an Interrupt Service Request (ISR) on the interrupt line it must determine which of the devices connected to that input sent the request.

Software Polling is one method by which it can do so.

In Software Polling:

A software routine is used to identify the device requesting service. It does so by checking each device to see if it was the one needing service.

Wednesday, 15 June 2011

hardware interrupts in 8085 microprocessor

Explain hardware interrupts in 8085.

• When a device interrupts, it actually wants the MP to give a service which is equivalent to asking the MP to call a subroutine. This subroutine is called ISR (Interrupt Service Routine)
• Interrupts:
• The 8085 microprocessor has 5 interrupts. They are presented below in the order of their priority (from lowest to highest):
• INTR is mask able 8080Acompatible interrupt. When the interrupt occurs the processor fetches from the bus one instruction.
• RST5.5 is a mask able interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 2Ch (hexadecimal) address.
• RST6.5 is a mask able interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 34Ch (hexadecimal) address.
• RST7.5 is a mask able interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 3Ch (hexadecimal) address.
• Trap is a non-maskable interrupt. When this interrupt is received the processor saves the contents of the PC register into stack and branches to 24h (hexadecimal) address.
• All maskable interrupts can be enabled or disabled using EI and DI instructions. RST 5.5, RST6.5 and RST7.5 interrupts can be enabled or disabled individually using SIM instruction.

Monday, 13 June 2011

Memory Mapping Scheme

What is the memory mapping scheme? Give any one advantage and disadvantage.

MEMORY MAPPING SCHEME:

WEB MAPPING:

Web mapping is the process of designing, implementing, generating and delivering maps on the World Wide Web and its product.

ADVANTAGE & DISADVANTAGE:

While web mapping primarily deals with technological issues, web cartography additionally studies theoretic aspects: the use of web maps, the evaluation and optimization of techniques and workflows, the usability of web maps, social aspects, and more.

Web maps can easily deliver up to date information. If maps are generated automatically from databases, they can display information in almost realtime. They don't need to be printed, mastered and distributed.

Reliability issues – the reliability of the internet and web server infrastructure is not yet good enough. Especially if a web map relies on external, distributed data sources, the original author often cannot guarantee the availability of the information.