Iyo ASCII chiyero yakagamuchirwa muna 1963, uye parizvino hapana anoshandisa encoding ayo ekutanga mavara 128 akasiyana neASCII. Zvisinei, kusvika pakupera kwezana remakore rapfuura, EBCDIC yakashandiswa zvakasimba - iyo yakajairwa encoding yeBM mainframes uye maSoviet clones EC makomputa. EBCDIC inoramba iri yekutanga encoding muz/OS, yakajairwa sisitimu yekushandisa yemazuva ano IBM Z mainframes.
Chii chinokurumidza kubata ziso rako kana uchitarisa EBCDIC ndechekuti mavara haasi mumutsara: pakati I ΠΈ J uye pakati R ΠΈ S pakanga paine nzvimbo dzisina kushandiswa (pakombiyuta yeES yenguva idzi Cyrillic mavara). Ndiani angadai akafunga kuvhara mavara ane nzvimbo dzisina kuenzana pakati pemavara ari pedyo?
Iro iro zita rekuti EBCDIC ("Yakawedzerwa BCDIC") rinoratidza kuti encoding iyi - kusiyana neASCII - haina kugadzirwa kubva mukutanga, asi zvichibva pane matanhatu-bit BCDIC encoding, yave kushandiswa kubvira. (1954):
Iko hakuna kukurumidza kumashure kuenderana: chinhu chiri nyore cheBCDIC chakarasika mukuchinja kuenda kuEBCDIC yaive iyo nhamba. 0-9 zvinoenderana nemakodhi 0-9. Zvisinei, pane mikaha yemakodhi manomwe pakati I ΠΈ J uye mumakodhi masere pakati R ΠΈ S vatove kuBCDIC. Vakabvepi?
Nhoroondo ye (E) BCDIC inotanga panguva imwe chete nenhoroondo yeBMM - kare pamberi pemakombiyuta emagetsi. IBM yakaumbwa nekuda kwekubatanidzwa kwemakambani mana, ayo epamusoro-soro tekinoroji yaive Tabulating Machine Company, yakavambwa muna 1896 naHerman Hollerith, muvambi. . Matabulata ekutanga aingoverenga nhamba yemakadhi akaroverwa akaroverwa pane imwe nzvimbo; asi muna 1905 Hollerith akatanga kugadzira decimal tabulators. Kadhi yega yega yedecimal tabulator yaisanganisira minda yehurefu husina tsarukano, uye manhamba akanyorwa mundima idzi mune yakajairwa desimali fomu akapfupikiswa pamusoro pedeki yese. Kupatsanurwa kwemepu kuita minda kwakatemwa nekubatanidza waya pane tabulator's patch panel. Semuenzaniso, pane iyi Hollerith punch kadhi, muLibhurari yeCongress, nhamba 23456789012345678 yakadhindwa zvakajeka, isingazivikanwe seyakakamurwa kuita minda:
Vanonyanya kuteerera vanogona kunge vakacherechedza kuti pamepu yeHollerith pane mitsara gumi nemiviri yemakomba, kunyange gumi inokwana nhamba; uye muBCDIC, pahukoshi hwega hwega hwemabhiti maviri akakosha, macode gumi nembiri chete ndiwo anoshandiswa kubva pagumi nematanhatu.
Zvechokwadi, izvi hazvisi masanga. Pakutanga, Hollerith aida mimwe mitsara ye "special marks" iyo isina kuwedzerwa, asi yakangoverengerwa - sematabulata ekutanga. (Nhasi tingavadaidza kuti "bit fields".) Mukuwedzera, pakati pe "special marks" zvaikwanisika kuisa zviratidzo zveboka: kana tabulation ichida kwete chete mari yekupedzisira, asiwo yepakati, ipapo tabulator yaizomira kana. yakaona shanduko mune chero yezviratidzi zveboka, uye mushandisi aifanira kunyora zvakare subtotals kubva kumabhodhi edhijitari pabepa, gadziridza bhodhi, uye kutangazve kutara. Semuenzaniso, pakuverengera masaramusi eakaunzi, boka remakadhi rinogona kuenderana nezuva rimwechete kana rimwe divi.
Pakazosvika 1920, apo Hollerith akanga atorega basa, βmataipa tabulatorβ akatanga kushandiswa, ayo akanga akabatanidzwa neterepupu uye aigona kudhinda matuta mashoma ega pasina kuda kupindira kwaanoita. Chakanga chanetsa manje chakanga chiri chokuziva kuti nhamba imwe neimwe yakadhindwa yairevei. Muna 1931, IBM yakasarudza kushandisa "special marks" kuratidza mavara: mucherechedzo mumutsara wechigumi nembiri wairatidza tsamba kubva. A up to I, muna 11 - kubva J up to R, pa zero - kubva S up to Z. Iyo itsva "alphabet tabulator" inogona kudhinda zita reboka rega rega remakadhi pamwe nedikidiki; muchiitiko ichi, mbiru isina kuputsika yakashanduka kuita nzvimbo pakati pemavara. Ndapota cherechedza kuti S inosarudzwa nemusanganiswa wegomba 0+2, uye 0+1 musanganiswa hauna kushandiswa pakutanga nekutya kuti maburi maviri ari padivi pemumwe mukoramu imwechete angakonzeresa matambudziko emuchina muverengi.
Iye zvino unogona kutarisa tafura yeBCDIC kubva pakona yakasiyana zvishoma:
Kunze kwekuti 0 uye nzvimbo yakadzoserwa kumashure, akanyanya kukosha mabhiti maviri anotsanangura "special mark" yakaroverwa mukadhi yepunch yemunhu anoenderana kubva 1931; uye mashoma akakosha mabhiti mana anosarudza dhijiti yakaroverwa muchikamu chikuru chekadhi. Symbol support & - / yakawedzerwa kune IBM tabulators mu1930s, uye iyo BCDIC encoding yeaya mavara inoenderana negomba musanganiswa wakaroverwa ivo. Paidiwa tsigiro yenhamba yakatokura yemavara, mutsara wechisere wairohwa seimwe βspecial markβ - nokudaro, paigona kuva nemaburi matatu mukoramu imwe. Iyi fomati yemakadhi akaroverwa yakaramba isina kushanduka kusvika pakupera kwezana ramakore. MuUSSR, vakasiya IBM's Latin nepunctuation encodings, uye kune mavara eCyrillic vakabaya akati wandei "special marks" kamwechete mumitsara 8, 12, 11 - isingaganhurirwe kumaburi matatu mukoramu imwe.
Pakagadzirwa komputa IBM 704, havana kufunga kwenguva refu nezve iyo encoding yayo: vakatora iyo encoding yakatoshandiswa kare mumakadhi akaroverwa panguva iyoyo, uye chete "kuiisa panzvimbo yayo." Muna 0, panguva yekuchinja kubva kuBCDIC kuenda kuEBCDIC, mabheti mana echiratidzo chega chega akasiiwa asina kuchinjwa, kunyange zvazvo mabhiti epamusoro akaiswa zvishoma. Nekudaro, iyo yakadhindwa kadhi fomati yakasarudzwa naHollerith pakutanga kwezana ramakore rapfuura yakapesvedzera magadzirirwo emakomputa ese eBMM, kusvika uye kusanganisira iyo IBM Z.
Source: www.habr.com