TARZHOI KODIRONII INFORMATSIYA

Kodironii raqamii ittiloothoi namudashon gunogun. Ravandi tashakkuli tarzi muayyani tasviri informatsiyaro kodironii (ramzsozi, ramzbandi) informatsiya meguyand. Odatan dar zeri mafhumi kodironii informatsiya guzarish az yak tarz ba digar tarzi tasviri informatsiyaro mefahmand, ki vay baroi nigahdori, intiqol va korkard qulaytar ast.

Kompyuter tanho namudi informatsiyaero kor karda baromada metavonad, ki vay dar shakli raqami tasvir shuda boshad. Har guna informatsiyai namudi digar – sado, navo, matn, grafik, rasm, nishondodi asbobho va gayra hangomi korkardi kompyuteri boyad avval ba shakli raqami tabdil doda shavad. Masalan, baroi sadoi musiqiro ba shakli adadi tabdil dodan, kifoya ast, ki dar fosilahoi nachandon kaloni vaqt balandii (shiddati) sadoro baroi zudihoi muayyan chen namoem va natijahoi chenkunihoro dar shakli raqami ba qayd girem. Bo yorii programmahoi kompyuteri boshad, in tabdilotro dar shakli sadoi musiqi az nav barqaror namudan mumkin ast.

Aynan hamin tavr, bo yorii kompyuter informatsiyai matniro niz kor karda baromadan mumkin ast. Hangomi ba kompyuter dokhil namudani ramzho (harf, raqam, alomat) onho bo yorii yagon adadi muayyan kodironida meshavand. Dar vaqti ba qismhoi beruna (ekran, printer) khorij namudan boshad, baraks, az rui kodi onho tasviri khudi ramzho sokhta meshavad.

Ana hamin muvofiqati bayni ramzhovu adadhoro ramzsozi meguyand. CHun qoida, hamai adadho dar kompyuter bo yorii raqamhoi nulu yak (0, 1) tasvir karda meshavand. YAne, kompyuter asosan dar bazai sistemai hisobi dui kor mekunad. Sababi asosii istifodai sistemai hisobi dui dar on ast, ki dar in mavrid tajhizoti korkardi informatsiya namudi khele soddaro qabul menamoyad.

Dokhilkuni va khorijkunii adadho bo yorii kompyuter boshad, dar shakli muqarrari (odati) ijro karda meshavad, chunki hamai tabdildihihoro programmahoi kompyuteri ba zimmai khud megirand. 

Andozagirii informatsiya va chenakhoi on. Odamon hangomi halli masalahoi mukhtalif beshtar az informatsiyai doir ba muhiti atrof doshtaashon istifoda mebarand. Agar in yo on ruydod yo hodisa khubtar va purratar omukhta shuda boshad, on goh halli masalai ba on muvofiq niz hamon qadar osontar yofta meshavad.

Masalan, donistani qonunhoi fizika imkoniyat medihad, ki asbobhoi murakkabi tekhniki sokhta shavand. Baroi tarjumai matn az zaboni khoriji boshad, donistani qoidahoi grammatiki va azyod kardani miqdori kalimahoi ziyode lozim meoyad.

Mo zud-zud az nazdikoni khud iborahoero meshunavem, ki guyo in yo on khabar informatsiyai kam yo baraks ziyodro dorost. Dar haqiqat ham, hamin tavr ast. Masalan, maqolai dar ruznoma chopshuda metavonad baroi yak shakhs miqdori ziyodi informatsiya dihad, ammo ba malumothoi peshtarai shakhsi digar yagon zarra informatsiyai navro zam nanamoyad. Sabab dar on ast, ki donishi odamon nisbat ba ittilooti (akhbori, hodisai) dar maqola bayonshuda, metavonad to chopshaviash dar sathhoi gunogun qaror doshta boshad.

Az digar taraf, bazan holathoe ruy medihand, ki shakhs az shunidani malumothoi ziyodi nav (masalan, darsi nav), baroi khud amalan yagon miqdor informatsiya namegirad. Sababi ruy dodani chunin holatho dar on ast, ki akhbori mazkur (mavzu) baroi shunavanda shavqovar nest, yane zavqi uro bedor karda nametavonad.

Hamin tariq, miqdori informatsiyai dar akhbor (malumot) mahfuzbuda az darajai navi va shavqovarii vay baroi qabulkunandaash vobasta ast. Bo giriftani informatsiyai zaruri nomuayyani dar (nopurragii donish) masalai baroi mo shavqovar kam meshavad. Agar dar natijai qabuli malumoti nav halli masalai omukhtashavanda purra ravshan gardad (yane nomuayyani gum shavad), on goh meguyand, ki informatsiyai mukammal girifta shudaast va zarurat ba giriftani informatsiyai ilovagi vujud nadorad. Baraks, agar pas az giriftani malumot nisbat ba masalai tadqiqshavanda nomuayyani boqi monad (malumot yo nav naboshad va yo ba masala dakhl nadoshta boshad), on goh meguyand, ki yagon informatsiya girifta nashudaast (informatsiyai nuli).

Masalan, agar hangomi partoftani tanga mo ahamiyat dihem, ki vay bo kadom tarafash meaftad, on goh hatman sohibi informatsiyai muayyan megardem.

Azbaski har du tarafi tanga imkoniyati aftidani barobarro dorand, binobar in ehtimoliyati ba bolo omadani ham in taraf va ham on tarafi tanga yakkhela ast. Dar in mavrid meguyand, ki hodisa yak bit informatsiya dorad. Aynan hamin tavr, hangomi az bayni du saqqoi ranghoi gunogundoshtai dar qutti pinhonbuda nodida giriftani yake az onho niz, mo informatsiyai ba 1 bit barobarro doir ba rangi saqqo dastras menamoem.

Vohidi chenkunii informatsiyaro bit (bit) meguyand, ki on az kalimahoi kutohkardashudai anglisii binary digit (raqami dui) girifta shudaast. Dar tekhnikai kompyuteri bit ba vazi fizikii barandai informatsiya muvofiqat mekunad. Masalan, magnit mekashad – magnit tela medihad, surokhi hast – surokhi nest, lampa furuzon hast – lampa khomush ast. YAke az vazhoro ba vositai raqami 0 va digarashro bo 1 ishorat kardan odat shudaast. Intikhobi yake az du varianti imkonpazirro bo doimihoi mantiqii «durust» va «nodurust» niz ifoda mekunand. Bo yorii paydarpayii bitho matn, musavvara, sado yo digar namud informatsiyaro kodironidan mumkin ast. Metodi bo bitho tasvirkunii informatsiyaro metodi kodironii dui (binary encoding) meguyand.

Dar informatika beshtar az buzurgii kalontar – bayt (byte) istifoda mebarand, ki vay ba 8 bit barobar ast. Agar bit imkoniyati az du varianti imkonpazir intikhob namudani yakero faroham ovarad, on goh bayt, muvofiqan, yake az 256 varianti imkonpazirro (28) peshkash menamoyad. Aksariyati kompyuterhoi zamonavi hangomi kodironii ramzho paydarpayii az 8 nulu yakho (yak bayt) iboratbudaro istifoda mebarand.

Muvofiqati bayni baytho va ramzho bo yorii jadvalhoi makhsus ba tanzim ovarda meshavand. Masalan, muvofiqi jadvali kodii Koi8-R kodi harfi M ba 11101101, kodi harfi I ba 11101001 va kodi ramzi probel (mavqei kholi) ba 00100000 barobar ast.

Dar barobari baytho baroi chenkunii miqdori informatsiya az chenakhoi boz ham kalontar istifoda mebarand:

1 Kbayt (yak kilobayt) = 210 bayt = 1024 bayt;

1 Mbayt (yak megabayt) = 210 Kbayt = 1024 Kbayt;

1 Gbayt (yak gigabayt) = 210 Mbayt = 1024 Mbayt.

Masalan, miqdori informatsiyai kitobi 100 sahifadoshtaro, ki har yak sahifaash 35 satr va har yak satrash 50-ramzi dorad, chunin hisob kardan mumkin ast: yak sahifai kitob 35·50=1750 bayt informatsiya dorad, hajmi informatsiyai purrai kitob boshad, ba 1750·100=175000 bayt yo 175000:1024=170,8984 Kbayt va yo 170,8984:1024=0,166893 Mbayt barobar ast.

Hudro sanjed:

1. Kodironii informatsiya chist? Kodironii raqami chi?
2. Sistemai hisobi dui chi guna sistema ast?
3. Miqdori informatsiyaro chi tavr chen mekunand?
4. Bit va bayt gufta chiro mefahmed? Boz kadom chenakhoro medoned?
5. Akhbori az 12288 bit iboratbuda, chand Kbayt informatsiyadorad?

Ijro kuned:

1. Mavzuro bodiqqat khoned va doir ba tarzhoi kodironii informatsiya malumot dihed.
2. Maktub az 2 sahifai 25-satra iborat ast. Dar har yak satri maktub 40 ramz joy doda shudaast. Hajmi informatsiyai maktubro hisob kuned.