input output

Input/output

In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it. The term can also be used as part of an action; to "perform I/O" is to perform an input or output operation. I/O devices are used by a person (or other system) to communicate with a computer. For instance, a keyboard or a mouse may be an input device for a computer, while monitors and printers are considered output devices for a computer. Devices for communication between computers, such as modems and network cards, typically serve for both input and output.

Note that the designation of a device as either input or output depends on the perspective. Mouse and keyboards take as input physical movement that the human user outputs and convert it into signals that a computer can understand. The output from these devices is input for the computer. Similarly, printers and monitors take as input signals that a computer outputs. They then convert these signals into representations that human users can see or read. For a human user the process of reading or seeing these representations is receiving input. These interactions between computers and humans is studied in a field called human–computer interaction.

In computer architecture, the combination of the CPU and main memory (i.e. memory that the CPU can read and write to directly, with individual instructions) is considered the brain of a computer, and from that point of view any transfer of information from or to that combination, for example to or from a disk drive, is considered I/O. The CPU and its supporting circuitry provide memory-mapped I/O that is used in low-level computer programming in the implementation of device drivers. An I/O algorithm is one designed to exploit locality and perform efficiently when data reside on secondary storage, such as a disk drive.

Interface

An I/O interface is required whenever the I/O device is driven by the processor. The interface must have necessary logic to interpret the device address generated by the processor. Handshaking should be implemented by the interface using appropriate commands (like BUSY, READY, and WAIT), and the processor can communicate with an I/O device through the interface. If different data formats are being exchanged, the interface must be able to convert serial data to parallel form and vice-versa. There must be provision for generating interrupts and the corresponding type numbers for further processing by the processor if required.

A computer that uses memory-mapped I/O accesses hardware by reading and writing to specific memory locations, using the same assembly language instructions that computer would normally use to access memory.

 Higher-level implementation

Higher-level operating system and programming facilities employ separate, more abstract I/O concepts and primitives. For example, most operating systems provide application programs with the concept of files. The C and C++ programming languages, and operating systems in the Unix family, traditionally abstract files and devices as streams, which can be read or written, or sometimes both. The C standard library provides functions for manipulating streams for input and output.

In the context of the ALGOL 68 programming language, the input and output facilities are collectively referred to as transput. The ALGOL 68 transput library recognizes the following standard files/devices: stand in, stand out, stand errors and stand back.

An alternative to special primitive functions is the I/O monad, which permits programs to just describe I/O, and the actions are carried out outside the program. This is notable because the I/O functions would introduce side-effects to any programming language, but now purely functional programming is practical.

Addressing mode

There are many ways through which data can be read or stored in the memory. Each method is an addressing mode, and has its own advantages and limitations.

There are many type of addressing modes such as direct addressing, indirect addressing, immediate addressing, index addressing, based addressing, based-index addressing, implied addressing, etc.

 Direct addressing

In this type of address of the data is a part of the instructions itself. When the processor interprets the instruction, it gets the memory address from where it can be read/written the required information. For example.

MOV register, [address] ; to read

MOV [address], register ; to write

; similarly

IN  register, [address] ; to read as input

OUT [address], register ; to write as output

Here the address operand points to a memory location which holds the data and copies it into/from the specified register. A pair of brackets is a

Indirect addressing

According to the above example, the address can be stored in another register. Therefore, the instructions will have the register representing the address. So to fetch the data, the instruction must be interpreted appropriate register selected. The value of the register will be used for addressing appropriate memory location and then data will be read/written. This addressing method has an advantage against the direct mode that the register value is changeable so the appropriate memory location can also be dynamically selected.

" I Like..but i don't like..."

.:sUkA:.

:.Suka membaca NOVEL dan KOMIK,tapi jarang beli:.

:.Suka melepak sambil merenung awan:.

:.Suka dengar lagu, tak kira genre :.

.:Suka mengusik orang, tak tau la orang suka ke tak:.

.:Suka makan coklat time tengah tension:.

.:Suka tolong mama masak:.a

.:Suka bila dapat manja @ mengada-ngada dengan mama n baba:.

.:Suka melancong,kalau boleh nak melancung 1 dunia:.

.:Suka online:.

.:Suka mengadap cerpen online,sebab 'free':.

.:tAk SuKa:.

.:tak suka bila nervous,sebab terus akan menangis:.

.:tak suka orang mengutuk kekurangan diri:.

.:tak suka orang yang suka tikam kawan sendiri:.

.:tak suka bila tension:.

Education background

Memang pelik kalo dalam blog tiba-tiba kena cerita pasal ni. tapi disebabkan ini merupakan salah satu kriteria yg perlu ada, jadi kenalah cerita juga.

Bersekolah rendah di Sekolah Kebangsaan Taiping, dari tahun 1-6(1994-1999). Berada dalam kelas Mawar dari mula sampai habis sekolah.

Sekolah Kebangsaan Taiping

Masuk tingkatan 1 saya bersekolah di Sekolah Menengah Kebangsaan Dr Burahnuddin. Sampailah habis tingkatan 5.Rasa-rasanya nilah masa yang paling seronok,sebab paling ramai kawan-kawan. Masa nilah masa paling nakal, almaklumlah jiwa remaja.

Habis je SPM sambung sekejap tingkata 6 dekat sekolah yang sama.Tapi dapat tawaran sambung belajar ke Politeknik Ungku Omar. Ni la kali pertama nak belajar jauh daripada mama dan baba. Sedihlah juga, tapi bila dah ada kat sini rumah pon jarang nak balik..Tapi jauh sangat ke Ipoh dengan Taiping?

Bolelahkan... Mengambil jurusan Sijil Teknologi Maklumat.Sangat meminati bidang ini.Seronok dapat belajar edit mengedit, multimedia dan macam-macam lagi.

Tunggu punya tunggu, niat hati nak sambung diploma teknologi maklumat, tapi dah bagai menunggu bulan jatuh keriba dah kan. Kerja sekejap kat sebuat cyber cafe. Dalam sedih-sedih tak dapat sambung sedangkan kawan-kawan lain dah sambung tiba-tiba dapatlah tawaran belajar dari UITM. Hati ni mula-mula memang berat sangatlah nak sambung sebab dapat course yang berbeza, tapi mama kata nak tunggu sampai bila? Kira rezeki tuhan ni. jadi disini lah saya sekarang. Di Uitm Seri Iskandar, mengambil jurusan teknologi pejabat. Memang lain sangat dengan juusan yang saya ambil di poli. Tapi Ilmu ni tak rugi kalo kita ambil.  Tambah ilmu didada.

"Sayang Semua"

"Sayang Semua"

"sayang bukan sebarang sayang, sayang utama kepada Allah,sayang juga kepada Rasul, sayang selebihnya kucurah pada Ayahanda, Bonda serta adik-adik"

Inilah insan yang telah banyak berjasa dalam hidup saya. Baba dan mama.tak terbalas rasanya jasa baba dan mama.semua orang sangat  sayangkan ibu dan bapa..saya pun sangat sayang dengan baba dan mama saya..adoiyai, tiba- tiba je nak sedih-sedih..tukar topik la...

ok, baba saya seorang yang sangat garang, dasyatnya bunyi...tapi masa-masa yang perlu garang je la...juga seorang yang sangat sporting...tapi kena tengok timing la kalau nak bodek apa-apa...yang paling best sangat penyayang...suka sangat bila baba gosok-gosok kepala masa time bagi nasihat..macam anak kucing je rase..manja la konon..tapi yang agak tak best siskit baba ni suka sangat cari gaduh dengan saya..gaduh-gaduh manja gitu..kalo tak gadih katanya bosan...hobi baba saya ni suka main game..kalau dah mengadap depan komputer tu yang mengantuk jadi segar, yang lapar pun terus jadi kenyang...satu benda lagi saya suka belajar matematik dengan ayah saya,soalan yang susah tu dengan senangnya boleh jawab..ini adalah petikan dari baba "matematik ni kita belajar sampai mati, masa akhirat nanti pon masih guna matematik".. Punya la dasyatnya matematik ni..

mama pun seorang yang sangat penyayang,selalunya saya akan kongsi masalah saya dengan mama, adik-adik lain kata saya ni anak manja mama,selalunya apa yang saya minta mama akan kata ok lepas tu bagi duit suruh beli sendiri..sapa suruh tak nak mintak, kalau mintak senang je dapat..selalunya mama akan meredakan gaduh-gaduh manja antara saya dengan abah..mama ni boelh taha la 'sporting' , tapi kalau mama dah naik angin baik duduk diam-diam, sekali mama dah panggil kakakkkkkk! habislah...jadi jangan nakal-nakal..hobi mama dengar radio,channel paling suka ialah Perak f.m. mama punya masakan,,fuuhhhhh...sedappp...selalunya mama akan masak sedap-sedap bila semua adik-adik ada dekat rumah..masa tu la yang paling seronok..

Ini pula adik kedua saya, nama dia syahirah aimi. dekat rumah panggil acik nampak macam pendiam, tapi sekali dapat bercakap tak henti-henti, macam keretapi ETS yang laju tu..seorang yang bijak, tapi datang time mengantuk habis semua buku dia lupa.

Yang sebelah kiri ni adik pertama saya, syuhada anis, dekat rumah panggil angah, angah ni seorang yang happy, hobi dia memasak kemudian makan, kadang-kadang boleh lah nak berkomplot nak beli apa-apa dengan dia tapi kalau time kedekut, janganlah nak komplot apa-apa, semua dia bangkang, tapi dialah tempat nak mintak tolong time terdesak.

Yang sorang lagi tu adik manja saya, nama dia najwa amni, dekat rumah semua panggil Abby. Hobi dia tengok kartun, sekali dia pegang remote control, semua orang tak boleh nak kata apa-apa...kalau nak tengok juga, tunggu di tidur. Hobi dia ialah membaca. Kalau buku tu dah jadi buku Favourite, sampai lembiklah buku tu jawabnya..

"Tak kenal maka tak cinta"

"Tak kenal maka tak cinta"

Jadi sape yang nak bercinta dengan saya kenalah kenal dulukan...jom berkenalan, nama panjang saya ialah NOORUL KHALISAH AIDA BT MOHD NAZRI.. sedapkan nama ni baba yang bagi,baba ni ayah sayalah..maksudnya cahaya keikhlasan..very the sincere tau...selalunyanye orang memang ada masalah nak ingat nama saya ni..senang je kan nak ingat..berasal dari TAIPING,PERAK tapi di lahirkan di KUALA LUMPUR, orang KL la ni kononya..dilahirkan pada 31 JUALAI 1987..senang je nak ingat sebulan sebelum kita merdeka..mama kata pada tarikh ni selalunya hari pahlawan..betul kot..hobi dimasa lapang SUKA MELEPAK MERENUNG AWAN, comel-comel je awan tu..selain tu SANGAT SUKA MEMBACA KOMIK DAN NOVEL..kadang-kadang datang mood happy sikit saya suka MEMASAK..memang pandai memasak,sedap ke tak kena lah cuba dulu..

.: assalamualaikum:.