🔙 Quay lại trang tải sách pdf ebook Giáo trình tin học đại cương Ebooks Nhóm Zalo Ill H KHANG (Chu bien) NGUYf: GT.0000026707 WaN UY, NGUYEN HONG PHU'ONG DO bA lam, dothingocquynh, dotuananh GIAO TRINH TfA/ H O C m c i M i c ; i TRAN DINH KHANG (Chu bien) NGUYEN LINK GIANG, DO VAN UY, NG UY£n HONG PHl/ONG, DO BA LAM, DO THI NGQC QUYTVH, D 6 TUAN ANH G I A O T R I N H TIN HOC DAI CtrONG (Tai ban Ian thir ba) NHA XUAT BAN BACH KHOA - H /lA ^ I B4n quyen thugc ve tru6ng D?i hgc Bich Khoa H i Npi. Mpi hinh thiic xuat bin, sao chep m i khong c6 s\r cho phep bing vim bin cua trubng li vi phmn phip lu|t. M i so; 22 - 2014/CXB/244 - 80/BKHN Bien muc tren xui't ban ph^m cua Thu viin Qu6c gia Viit Nam Gido trtnh tin hpc dai cirong / TrSn Dinh Khang. Nguyfin Linh Giang, D6 van Uy... - Tii ban iSn thii rMt c6 siira chfla vi b6 sung. - H .: Bich khoa H i Ndi, 2014. - 246tr.: hmh ve, bing .;24cm, Thu muc: tr. 245 ISBN 978-604-911-829-6 1. Tin hoc dai cuong 2. Liptnnh 3. Thuittoin 4. Giiotnnh 005.1 -dcl4 BKB0050p-CIP LOfI NOI d Au Gido troth Tin hpc d^i cuomg dugc bien soan theo chiromg trinh mon hQC Tin hpc d^i cvong gidng day tai Truong Dai hpc Bach Khoa Hi Npi. Giao trinh cung c6 the lam tii lipu hpc tap cho sinh vien cac truong Dai hpc, Cao ding ky thuat va cong nghp Tong ca nuoc. Vdi nyc tieu cung cap tai lipu hpc tpp cho sinh vien, nhom tic gia di tap hpp bai giang va kinh nghipm ciia nhieu thay, c6 giao trong Vipn Cong nghp thong tin va Truyai thong, Truong Dai hpc Bach khoa Ha Npi de bien tap thanh giao trinh nay. Bo cvc giao trinh gdm ba phan chinh nhu sau: Phan I: Tin hgc can ban. Phin nay trinh biy ve thong tin, du lipu, hp thong may tinh vi cac hp thong ung dyng. Day la nhCmg kien thtic c5n ban ve tin hpc va may tinh, giup cho ngucri hpc co nen tang tot khi buoc tiep vio the gioi v6 ciing rpng Idn thipc ITnh vyc cong nghp thong tin. Phan II: Giai quyet bdi loan. Npi dung phan nay gioi thipu ve giai quySt bai toan, bieu dien thuyt toan va cac thuyt toan thong dyng. Voi kinh nghipm nhieu nim thatn gia giang dyy, cac tac gii nhyn thiy, khong it sinh vien thanh thyo ve tin hpc vi lip trinh nhung van thuong to ra Iting tung khi dung truoc mpt bai toin thyc te cin giai quyet. Do do, phan nay giiip sinh vien c6 dupe tu duy ban dau vi biSt cich ap dyng cic kien thuc tin hpc de giii quyet mpt bii toan trong thyc tien. Phan III: Lqp trinh. Day li phan trpng tarn ciia giio trinh. gioi thipu nhftng kien thuc nen ting ctia ngon ngO- lap trinh C, mpt ngon ngii mi hau het lap trinh vien chuyen nghipp deu su dyng. Cuoi moi phin li mpt so cau hoi vi bii tap nhim giup byn dpc cting c6 nhinig kien thuc da hpc. Cic tic gii xin biy to sy biet cm chan thinh doi voi cic thay c6 giio, cic dong nghi§p trong Vipn Cong nghp thong tin vi Truyen thong, Truong Dyi hpc Bich Khoai Hi Npi, da giup do vi dpng vien rat nhieu trong qui trinh bien soyn giio trinh. Die bipt, xin gui loi cam om sau sic toi PCS. D$ng Vin Chuyet vi TS. Phym Ding: Hii da dinh thoi gian dpc bin thio vi cho nhung y kien dong g6p quy biu. Prong qud trinh bien scan, mac dii d§ rat c6 ging, nhimg sai sot la dieu kho tnranh di6i, ckc tic gia rat mong nhan du ly thdng tin Mpi qua trinh xu ly thong tin bing may tinh hay hoi con ngucri deu dupe tthnyc ipn theo mpt quy truth nhu sau; Dft lipu (Data) dupe nhap a dau v^o (Input), qua qud trinh xu ly de nhan dtuape long tin d dau ra (Output). Dll' lipu trong qua trinh nhyp, xu ly va xuat deu c6> tithe jpe luu tra. NHAPDU'LI$U (INPUT) XTyLY (PROCESSING) LUXJ TRU" (STORAGE) XUAT DC lieu (OUTPUT) Hinh LI. Xir ly thong tin bang may tinh difn tu Du lipu dupe thu thyp v i luu trii, qua qui trinh xu ly c6 the trdr thanh du li«pu idi dS theo mpt qud trinh xii ly dO lipu khde tyo ra thong tin moi hon theo y do criia tn nguiri. Con nguiri c6 nhieu edeh de c6 da lipu vd thong tin. Ngudri ta c6 the luu trra long tin qua tranh vg, giay, sdeh bdo, hinh anh trong phim, bing tu. Trong thiri dlyi ipn nay, khi lupng thong tin den vdi chung ta cang luc cang nhieu thi con ngufui S the dung mpt cong cy ho trp cho vipc luu trii, chpn Ipc vd xu ly thong tin gpi lla idy tinh dipn tu (computet). Miy tilth dipn tu giup con ngu6ri tiet k i ^ rat nhiMu liri gian, cong sue vd ting dp chinh xdc cao trong vipc ty dpng hod m$t phan haay )dn phan cua qud trinh xa ly thong tin. 12 1.11.2. May ti'nh dif n ti> va phan lo^i a. Iguy6n ly Von Neumann Npyen ly nay mang ten nguoi phat minh ra no, nha toan hpc nguoi My goc Hogary, John Von Neumann (1903 - 1957) (ten khai sinh la Neumann Janos Laos). Day la mpt trong nhung phat minh vT dai cua nhan loai trong Ijch su phdt trin ciia may tinh. NSn 1946, Von Neumann d3 de ra mpt nguyen ly may tinh boat dpng theo mpt ch;cmg trinh dirpc luu tru va truy nhap theo dia chi. Nguyen ly nay dupe trinh bay 6 npt bai bao noi tieng nhan de "Thao luan so bp ve thiet ke logic ciia may tinh dih tit". Npi dung nguyen ly Von Neumann gom: - /dry tinh c6 the boat d0ng theo mpt chuang trinh da duprc luu tru Tho Von Neumann, chung ta c6 the tap hpp c3c Ipnh cho may tinh thi h3nh theo me chuang trinh dupe thiet ke va coi d6 nhu mpt tap du lipu. Du lieu nay dupe cai v3i trong mdy vd dupe truyen bang xung dipn. Day la mpt cupc edeh mang moi chc mdy tinh nham tdng toe dp tinh todn vao then d6 vi trude kia, mdy chi c6 the nhn dupe ede Ipnh tir bang giay hoac bia dpc lo vd nap vdo bdng tay. Neu gap bdi tom lap Ipi nhieu Ian thi phdi nap lai mpt edeh thii cong nhu vay, gay hpn che trong tini todn sii dpng. - Id nha duac dfa chi hoa Md du lipu deu c6 mpt dja chi ciia vimg nhd chua du lipu do. Nhu vpy, de truy nhp du lipu, ta chi can xdc djnh dja chi cua no tren bp nhd. - Ip dim cua chuang trinh Net moi cau Ipnh phdi dung mpt vung nhd de chua dia chi cua cau Ipnh tiep theo thikhong gian bp nhd sS bj thu hpp. De khac phpc hpn che ndy, mdy dupe gdn mpt thaih ghi de chi ra v) tri ciia Ipnh tiep theo can dupe thpc hipn vd npi dung cua no t\r tpng dupe tdng len moi Ian Ipnh dupe truy cap. Muon doi thu tp Ipnh, ta chi edn tha' doi npi dung thanh ghi bdng mpt dja chi cua Ipnh can dupe thpc hipn tiep. b. Ijch s u p h it triin cua m iy tinh di^n tCr Donhu cau can tdng dp chinh xdc vd gidm thdi gian tinh todn, con ngudi dd quan tan che tao cac edng cp tinh todn tir xua: bdn tinh cua ngudi Trung Quoc, mdy cpig CO hpc cua nhd todn hpc Phdp Blaise Pascal (1623 - 1662), mdy tinh co hpc c6 he cpng, trir, nhan, chia cua nhd todn hpc Due Gottfried Wilhelmvon Leibniz (1(46 - 1716), mdy sai phan de tinh ede da thiic todn hpc,... 13 Tuy nhien, may tmh di?n tur chi th\rc sy dugc bat dau hinh thanh vao th 4 p 'nien 1950, den nay da trai qua nhieu the h?, dga vao sg tien bp ve cong nghe diem tui va n dipn tii cung nhu cac cai tien ve nguyen ly, tinh nang va loai hinh cua no. • The hp 1 (1950 - 1958): May tinh sii dgng cac bong den dipn ttur chan khong, mach rieng re, vao so lipu bang phieu dpc lo, dieu khien bSnig tay. May CO kich thuac rSt Idn, tieu thu nang luong nhieu, toe dp tinih clhSm khoang 300 - 3.000 phep tinh/giay. Loai may tinh dien hinh the htp 1 la ENTAC, EDVAC (My) hay BESEM (Lien X6 cQ),... • ThS hp 2 (1958 - 1964): May tinh dung bp xii ly bang den ban d in , rraach in. May tinh da c6 chuomg trinh djeh nhu Cobol, Fortran va hp dieu. hanh dom gian. Kich thude may c6n Idn, toe dp tinh khoang 10.000 — H0i0.;000 phep tinh/giay. Dien hinh nhu lopi IBM-1070 (My) hay MINSK (Liem X6 cu),... • The hp 3 (1965 - 1974): May tinh dupe g3n ede bp vi xit ly bang vi ira^ich dipn tu c5 nho, c6 the c6 dupe toe dp tinh khoang 100.000 - l.OOiO.OOO phep tinh/giay. May da c6 ckc hp dieu hanh da chuomg trinh, nhieu mgudi d6ng thai hoac theo kieu phan chia then gian. Ket qua tir mdy tinh c<6 ithe in ra true tiep a may in. Dien hinh nhu loai IBM-360 (My) hay EC (Lien X6 cu),... • The hp 4 (1974 - nay): May tinh bat dau c6 ede vi mach da xu ly c6 toe dp tinh til hdng ch\ic tripu den hang ty phep tinh/giay. Giai dopn nay hinh thdnh hai loai may tinh chinh: may tinh ca nhan de ban (Personal Computer - PC) vd mdy tinh xdch tay (Laptop ho|c Notebook). Ngodi ra c6n c6 ede lopi mdy tinh chuyen nghipp thpe hipn da chuomg trinh., da xu ly,... hinh thdnh ede hp thong mpng may tinh (Computer Networks) vd ede ung dpng phong phu da phuomg ti§n. • The hp 5 (1990 - nay): Bdt dau ede nghien cuu t^io ra ede mdy tinh mo phong ede boat dpng cua ndo bp vd hdnh vi ciia con nguiri, c6 tri khon nhan tao vdi khd ndng tp suy dien, phdt trien ede tinh huong nhan dupe vd hp qudn ly kien thurc co bdn de gidi quyet ede bdi todn da dpng. • Mdy tinh lupng tu: Nguoi ta hi vpng vd cung dd bit tay vdo vipc nghien cuu vd xay dpng ede mau mdy tinh lupng tu (c6n gpi la quantum computer) - loai mdy tinh c6 khd ndng gidi quyet epe nhanh nhung van dS 14 phuc tap ma cac sieu may tinh hi?n nay du mat hang trieu n5m cung chua tim ra lai giai. Nguyen ly ca ban ctia no la tto dyng cac quy luat ca hpc lucmg tu cho phep mpt hat, mpt nguyen tit hoic mpt phan tii ton tai a hai trang thai ciing mpt liic. Trong khi cac may tinh hipn nay lim trif dir lipu dudi dang cac bit d mpt trong hai trang thai 0 ho^c 1 thi may tinh lupmg tu luu tru du lieu bang cac bit luong tu (gpi la qubit) d dong thdi ca hai trang thai 0 va 1. Tren ly thuyet, uu diem cua loai may tinh nay la kha n3ng luu tru thong tin cua nhieu giai phap tiem nang cho mpt van de trong ciing mpt bp nhd va xu ly tat ca cac giai phap trong ciing mpt thdi diem bang cac thuat toan phii hprp. c. Pho lo^l may tinh 6i^n ti> Ten thpc te, ton tai nhieu each phan loai may tinh khac nhau. D\ra tren hipu nang inh toan, may tinh dupe phan loai nhu sau: • May vi tinh (Micro-computer hay PC): Loai nay thudng dupe thiet ke cho mpt ngudi dimg, do do gia thanh re. Hipn nay, may vi tinh kha pho dpng va xuat hipn dudi kha nhieu dang: may de ban (Desktop), may tram (Workstation), may xach tay (Notebook, Laptop) va miy tinh bo tiii. • Mdy tinh tam trung (Mini Computer): La loai may tinh cd toe dp va hipu nang tinh toan mtuih hem cac may vi tinh. Chung thudng dupe thiet ke de su dpng cho cac ung dpng phiic tap. Gia cua cac may n^iy cung c5 hang v^i chpc nghin USD. • M iy tinh Idn (Mainframe Computer) va Sleu m iy tinh (Super Computer): L^ nhung may tinh cd to chuc ben trong rat phuc tap, c6 toe dp sieii nhnnh vd hi9U nfing tinh toan cao, c5 hdng ty phiip tiull/gidy. Cdc mdy tinh nay cho phep nhieu ngudi dung dong thdi va dupe su dung tai cac trung tam tinh toan, vipn nghien cuu de giai quyet ede bai toan epe ky phtic tap, yeu cau cao ve toe dp. Chung cd gia thanh rat ddt, c9 hang trdm ngan, tham chi hang tripu USD. Tluo quan diem khac, may tinh dupe phan loai nhu sau: • Mdy tinh d l bdn (Desktop Computer): La loai may tinh phd bien nhat. Cd hai loai la mdy tinh cd nhan (Personal Computer - PC) va mdy tinh tram lam vipc (Workstation). Gid thanh tir khodng 500 USD ddn 10.000 USD. 15 • M iy chu (Server): L i lo?i may rinh dung trong mang may tfnh theo) mo hinh khich/chu (Client/Server). Day th\rc chat la may phyc v\i, c6 toe dl0 hi?u ning tinh todn cao, dung lugmg bp nhd Ion, dp tin c0y cao. G ia tlhinh tu khoang chpc nghin USD den h^ing ch\ic tripu USD. • M6y tinh nhung (Embedded Computer): Li loai may tinh dupe th iet ke chuyen dpng vi dupe djt trong ede thiet bj de dieu khien hopt d$mg ciia thiSt hi niy. Vi dy: dipn thopi di dpng, mdy dnh ky thupt so, bp dieu khien trong mdy giSt, mdy dieu h6a, bp dinh tuyen tren mang (router)i,... Gia thanb dao dpng tir vii USD den hing trim nghin USD. 1.1.1.3. Tin hQC va ede nganh cong ngh$ lien quan a. Tin hQC Thupt ngO Tin hpc c6 nguon goc tir tieng Due vao ndm 1957 do Karl Steinibucih de xuat trong bii bao "Informatik: Automatische Informationsverarbeitung"' (tieng Anh, "Informatics: Automatic information processing"). Sau d6, vao nSm 1962, Philippe Dreyfus nguoi Phdp gpi la "informatique", t i ^ theo, Walter F.Bauer cung sii dyng ten niy. Phan 1dm ede nude Tay Au, trir Anh, deu chap nhpn. C) Anh, ngudi ta sir dvmg thupt ngO "computer science" hay "computing science" la thmat ngu djeh, Nga cung chap nhpn ten "informatika" (1966). Tin hpc dupe xem la nganh khoa hpc nghien cuu ede phuong phdp, cong nghp va k^f thupt xd ly thong tin mpt edeh ty dpng. Cong cy chii yeu su dyng trong tin hpc Id mdy tinh dipn tu vd ede thiet bj truyen tin khde. Npi dung nghien ctru cua tin hpc chu yeu gom hai phan: • Ky th u |t ph4n cirng (Hardware engineering): Nghien cuu che tpo ede thiet bj, linh kipn dipn tu, cong nghe vpt lieu mdi... ho trp cho vipc thiet ke che tpo mdy tinh vd mpng mdy tinh, day mpnh khd ndng xir ly vd truyOT thong. • Ky thuat phan mem (Software engineering): Nghien cuu phat then ede he dieu hdnh, ede tipn ich chung cho mdy tinh vd mang mdy tinh, ede phan mem ung dyng phyc vy ede myc dich xu ly vd khai thde thong tin khde nhau cua con nguoi. b. C6ng ngh^ thdng tin Thupt ngil: Cong nghp thong tin (Information Technology, viet tit Id IT) xuat hipn a Vipt Nam vdo nhihig ndm 90 cua the ky XX. Theo Hipp hpi Cong nghp thong tin Hoa Ky (Information Technology Association of America, viet tdt la ITAA): 16 "Coi? ngh? thong tin la nganh nghien ctcu cdc h? thong thong tin dua veto may tinh.dac bi^t la cdc phdn mem img dung vd phdn cimg mdy tinh. N6i mQt edeh ngdigQn, IT xu ly v&i cdc mdy tinh di^n tie vd cdc phdn mem mdy tinh nhdm chuyn doi, lint trie, bdo v^, truyen tin vd trich rut thong tin mpt edeh an todn". ThecNghi quyet 49/CP ngay 04/08/1993 cua Chi’nh Phu Viet Nam thi "Cong nghe than tin (CNTT) Id tap hprp cdc phuomg phdp tdioa hoc, cdc phuemg ti^n vd cong cu k thugt hien dgi - chu yeu Id ky thudt mdy tinh vd vien thong - nhdm to chtec, khai hdc vd su dung c6 higu qua cdc nguon tdi nguyen thong tin rat phong phu vd tiem dng trong mgi ITnh vuc hogt dgng cua con ngudi vd xd hoi" Cdc Tig dqng ngay nay ciia Cong ngh? thong tin: ' Cdc bdi todn khoa hge ky thugt: Tinh toan so voi cdc thuat toan phiic tap can th\rc hi?n hang tram tri?u den hang ti phep tinh nhu xu ly cac so li?u th\rc nghi?m, quy ho^ch va toi uu h6a, gidi gan dung cdc h? phuong trinh. Cong trinh lap ban do gen ngudi hoan thdnh trong ndm 2000 phai tinh todn nhieu ndm trdi tren cdc sieu mdy tinh la mqt vi d\i. « Cdc bdi todn qudn ly: Xii ly mqt kh6i lugmg thong tin luu tru Idn (cdc h6 so) voi nhung cong vi?c nhu tao l$p co sd du li?u, duy tri co sd dd li?u, khai thde, ho tre? cho qud trinh ra quyet djnh. Ngudi ta ude tinh, khoang 85% nguon lye dau tu cho tin hge la danh cho bai todn quan ly. • TV dgng hoa: Co the t\r dgng hda nhung quy trinh dieu khien phiic tgp, cd tinh mem deo, co the thay ddi hanh vi t\r dgng hoa bing edeh lap trinh lai. Thiet bi duijrc dieu khien vd mdy tinh dieu khien trong da so trudng hgp khong tach rdi nhau. Cdc mdy mdc trd nen "thong minh" nhd cdc bg vi xu ly vd bg nhd ROM dugc cay tr\rc ti^ vdo mdy. • Cong tdc vdn phdng: Day Id nhOng ho?it dgng khd pho bien vd dugc chu y sdm. Cac cong vige nhu tao vdn bdn, in an, gui thu,... trd nen nhanh chdng vd thuan tign. • Gido due vd ddo tgo: Ho trg ngudi day trong vige trinh bdy bdi gidng, bo sung kien thuc, giup kiem tra, ddnh gid trinh dg ngudi hgc. Moi trudng internet md ra nhung khd ndng mdi trong gido dgc vdo dao tao tir xa. • Thiecmg mgi dign tir. Ho trg cac boat dgng thuomg mai qua mang mgt edeh nhanh chdng vd thuan tign. Mgt sd hinh thuc nhu qudng cdo tren m ^g, mua bdn hdng hda, djeh vg vd thanh toan qua mang. Thdch thuc Idn nhdt cua thuong m^i di^n tvi la van de phap ly vk dp an loan, tin cay trong ( cac giao dich dipn tu. • Lfng dung trong cuqc song thu&ng ngdy: Cac may moc, do dien tOr, , do gia dyng dupe dieu khiSn bang chip voi cac chuomg trinh dicu khhien thong minh. r. Cong ngh$ thong tin vk truy4n thong ■Jgay nay, ngucri ta c6 khuynh huong su dpng "information" thay the cho "daata" rk c6 XU thS mdr rpng cho llnh v\rc truyen thong, IT tra thanh ICT (Informatition ind Communication Technology, djeh la "Cong nghp thong tin va Truyen thongg"). rhuan tuy theo edeh noi thi hai thuat ngu nay la nhu nhau. rruy6n thong mdy tinh, noi dom gian la sp ket n6i mpt s6 lupng may tinh vdi nhhau rong mpt pham vi dja ly nho. Tuy nhien, nhieu may tinh c6 the ket noi vai nhhau heo mpt p h ^ vi rpng hon va vipc trao doi du lieu giua cac may tinh dupe thhpc lipn thong qua mpt mang vien thong nio d6. Internet - Mgng may tinh toan cauu la npt phat minh vT dai cua nhan loai trong the ky XX, do cung chinh la san phaam :iia ng^nh Cong nghp thong tin vi Truyin thong. .1.2. Bieu diln dip li$u trong may tinh .1.2.1. Bilu diln s6 trong cac h# dim Hip dem la tap hpp cac ky hipu va quy tic dung de bieu dien va xac djnh cac gia i tri :ua cic so. Moi hp dem c6 mpt s6 chir so hOu h ^ (chO s6 - digits, mpt so tai lilipu :6n gpi la ky so hay ky tp). T ong so ch u so cua moi hp dem d u p e gpi la cor .so (baase lay radix), ky hipu la b. i. H# dim c v s6 b Up dem co so b (b > 2 vi nguyen duomg) mang tinh chat sau : • C6 b chiJ so de the hipn gia trj so. Chu so nh6 nhat li 0 vi Ion nhat li b — 1. • Gii sir so N trong hp dem co so b dupe bieu dien duai dang: (b) 18 trcng do, so N c6 n+1 chir so bieu dien cho phan nguyen va m chu so bieu dien (b) cb phan thap phan. Gia tri cua so N trong h? thap phan la: (b) ~ ^ n - \ * + ... + ^?j A* + ^0*^^ ^ ^-I ^_2*^ ^ ha': Tnng ng^nh todn - tin hpc hi^n nay, pho bien bon hp dem la h? thap phan, hp nhj pKn, he bdt phan va he thap luc phan. b. i$ (Jim th$p phSn (Decimal system, b = 10) Hi dem thap phan hay hp dem ea so 10 la mpt trong cac phat minh cua ngucri A-rap CO, bao gom mucri chu so sau: 0,1, 2,3, 4, 5, 6, 7, 8, 9. Qty tic tinh gia trj cua hp dem nay b moi don vj a mpt hang bat ky c6 gia tri b§ng lOdon vi cua hang ke can ben phai. C) day b = 10. Bat ky so nguyen duomg nao trag hp thap phan cung c6 the bieu dien nhu b mpt tong cac so hmig, moi so h?uig b I'ch cua mpt so vdi 10 luy thira, trong do so mu luy thira dupe tang them 1 don vj) ngrijic lai. ViJu: Doi tit h? thap phan sang h? nhj phan so Dung phep chia cho 2 lie; tiep, ta c6 mpt loat cac so du nhu sau: Kequa: 12(io)= 1100('(2) 21 Doi phan thdp phdn tir thdp phdn sang h4 caso b T6ng quat: LSy phin thap phan N Ian lu<;rt nhan voi b cho den khi phin t thap phan ciia tich so bang 0. Ket qua so chuyen doi la cac so phan nguyen tnrong phep nhan viet ra theo thu t\r tinh toan. Vi d\i: 0.6875(10) = ? (2) 0.6875 X 2 = 0.375 x 2 = 0.75 x 2 = 0.5 X 2 = Ket qua: 0.6875(io) = 0.1011(2) Phan nguyen cua tich Phin thap phan cua tich .75 .5 .0 Litu y: chuy^ doi giua h? nhj phan va h? thap Iqc phan. De chuyen doi tir h?; nhj phan sang h? th|lp Iqc phan, ta duy?t tir phai sang trdi, chia thanh cac nhom bon i bit, sau do thay timg nhom bon bit nky b ^ g mqt chO so Hexa theo bang sau: 0 0000 0 1 0001 1 2 0010 2 3 0011 3 4 0100 4 5 0101 5 6 0110 6 7 0111 7 8 1000 8 9 1001 9 10 1010 A 11 1011 B 12 1100 C 13 1101 D 14 1110 E 15 nil F 22 Vi a: 111110(2) chinh la 0011 1110(2) = 3E(i6) 0011 1110(2) = 3E(16) 1.1.12. Bieu dien du’ lif u trong may tinh va do>n v| thdng tin a. Nuyen tic chung Thog tin va du li?u ma con nguoi hieu dugc ton tai dudi nhieu d ^ g khac nhau, vi dv nu cac so li?u, cac ky t\r vSn ban, am thanh, hinh anh,... nhung trong may tinh mpi long tin va du lieu deu dupe bieu dien bang so nhj phan (chuoi bit). De aa du lipu vao may tinh, can phdi ma hoa no ve dang nhj phan. Vdi cac kiSu du liu khac nhau can c6 each m3 hoa khac nhau. C\t the; ' Cac du lieu dang so (so nguyen hay so thpc) se dupe chuyen doi tr\rc tiep thanh cac chuoi so nhj phan theo cac chuan xac djnh. < Cac ki tu dupe ma hoa theo mpt bp m3 cp the, c6 nghla la m6i ky tp se tuemg ung vdi mpt chu6i so nhi phan. • Cdc du lipu phi so khac nhu am thanh, hinh anh va nhieu dai lupng vat ly khac muon dua vao may phai so ho3 (digitalizing). C6 thi hieu mpt each dom gian khai nipm so hoa nhu sau: cac dit lipu tp nhien thudmg la qua trinh bien doi lien tpc, vi vay de dua vao may tinh, no can dupe bien doi sang mpt d3y huu han cac gia tri so (nguyen hay thpc) v3 dupe bieu dien dudi dpng nhj phan. Vdi cac tin hipii nhir am thanh, video hay cic tin hi?u v |t ly khac, quy trinh m3 hoa dupe bieu dien nhu sau: Tin hipu vat ly Tin hipu Tin hipu so dipn lien tpc Hinh 1.2. Qua trinh so hod tin hifu vgt ly 23 Tuy ring mpi dft li?u trong mdy tinh deu 6 d ^ g nhj phan, song do ban chat cciiia du li?u, ngudi ta thuong phan dO li?u th^inh hai dang: • D?ng cor bin: Gom dang so (nguyen hay th\rc) va d ^ g ky tyr. So nigmyen khong dau du(jfc bieu dien theo dang nhj phan thong thuong, so ngujyen c6 diu theo m3 bit hai, con so th\rc theo d ^ g dau phay dpng. De biem dien mpt dG li?u CO ban, nguoi ta su dyng mpt so bit. Cac bit nay ghi6p Il?iii voi nhau de tao th3nh cym: cum 8 bit, cym 16 bit,... • D^ng c6 cau true: Tren co so du liyu co ban, trong mdy tinh, ngiiori tai xay dyng nen cAc dO liyu c6 cau true phyc vy cho cac myc dich su dyng JkhAc nhau. Tuy theo cAch "ghep" mA chiing ta c6 mAng, tap h(jfp, xau, bAn ghii,... b. Don vf thdng tin Don vi nhd nhat de bieu dien thong tin gpi lA bit. Mpt bit tuong ung vdi nn^t sy kipn c6 mpt trong hai tryng thAi. Vi dy: Mpt mych dAn c6 hai trang thAi 13: • T3t (Off) khi mach dipn qua cong tie 13 ho. • Mb (On) khi mach dipn qua cong tic 13 dong. So hpc nhj phan su dyng hai chG so 0 v3 1 de bieu dien cAc so. Vi kha n in g su dyng hai so 0 v3 1 13 nhu nhau nen mpt chi thj chi gom mpt chft so nhj phan c6> the xem nhu 13 don vj chiia thong tin nho nhat. Bit 13 chft viet tit cua Binary digiT. Trong tin hpc, ngubi ta thubng su dyng cAc don vj do thong tin Ion horn nhu sau: Ten gpi Ky hipu GiA trj Byte B 8 bit KiloByte KB 2'“ B = 1024 Byte MegaByte MB 2^“B GigaByte GB 230 b TeraByte TB 2^B 24 1.1.13. Bilu diSn s6 nguyen So nuyen gom so nguyen khong dau so nguyen c6 dau. Ve nguyen tSc, deu dunjmpt chuoi bit de bieu dien. a. SinguySn khdng d4u Tror; biSu dien so nguyen khong diu, mpi bit dSu dupe su dpng de bieu diin gia trj Si Vi dp, mpt d3y 8 bit dung de bieu dien s6 nguyen khong dau, c6 the bieu dientuac 2 = 256 so nguyen khong am, c6 gia trj tir 0 (0000 0000) den 255 (1111 111). Voi 16 bit thi dai bieu dien la [0, 65535]. Voi 1 bit, ta c6 the bieu dien mpt so nguyen o6 gia trj l(im nhat la 2" - 1 va Ak\ gia trj b:u dien la [0, 2" - 1], Vi d: Voi 8 bit 0000 0000 = 0 0000 0010= 2 0000 0100= 4 nil 1111= 255 Tr\us6 hpc ciia may tinh bieu dien so nguyen khong dau 8 bit: b. S< nguy4n c6 d iu Si nguyen c6 dau the hipn trong mSy tinh a dang nhj phan li so dung mpt bit lamtit dau, nguoi ta quy ude dirng bit 6 hang dau tien ben trai lam bit dau (S): 0 bieu dien so khong am vi 1 bieu dien so am. Vi dp: Mpt d3y 8 bit dung de bieu 25 dien so nguyen c6 dau, c6 the bieu dien dugc 2 = 256 so nguyen c6 dau, c6 ggid tri tu -128 (1000 0000) d6n +127 (0111 1111). Voi 16 bit, dai biSu dien la [-322768, +32767]. Voi n bit, ta c6 dii bieu dien la [-2"“‘, 2"-' - 1], Cdch pho bien bieu dien so am c6 dau la dung ma bu hai nhu sau: - BiSu dien so nguyen khong dau. - Nghich dao tat ca cac bit (so bu mpt). - Cpng them mpt (so bii hai). Vi dp; Bieu dien tren 8 bit: 37 Bii mpt (nghich dao) Bii hai (cpng them 1) = 0010 0101 = 1101 1010 1 11011011 =>s6 -3 7 1 Bit dau Thu bieu dien ma bid hai cua -37 de thu du(xc so +37 Trpc so hpc mdy tinh bieu dien so nguyen c6 dau 8 bit: 26 c. Tin toan s6 hqc voi so nguyen Cgng/rir s6 nguyen C(5/Jg tiif so nguyen khong ddu Khi ong hai so nguyen khong dau n bit ta thu duoc mot so nguyen khong dau cung bit. Vi vay: • Ncu tong ctia hai so do nho hon hoac bang 2" - 1 thi ket qua nhan duqc la diing. • Neu tong cua hai so do Idn hem 2" - 1 thi khi do se tran so va ket qua la sai. Vi du Vai tnrbmg h(?p 8 bit, tong nhd hem 255 thi ta se c6 ket qua dung; 57 = 0011 1001 + 34 = 0010 0010 91 = 0101 1011 trong ;hi do, phep cpng giua hai so 209 va 73 c6 ket qua nhu sau; 209 = 11010001 + 73 = 0100 1001 282 =03001 1010 i Bit tran ra ngoai => ket qua = 26 la sai. Detranh hien tupng tran so nay, ta phai su dung nhieu bit hem de bieu dien. Cqng/rit so nguyen c6 ddu So ngiyen c6 dau dupe bieu dien theo m3 bit hai, vay quy tic chung nhu sau; 27 COng hai so nguyen c6 dau n - bit sS bo qua gii trj nha ra khoi bit cc6 y nghia cao nhat, tong nh|ln du(7c se c6 gia trj dung va cung dugrc bieu i dien theo m2 bii hai, neu ket qua nhan dugrc n2m trong dai - 2 " den 2"“' - 1J. De trir hai so nguyen c6 dau X va Y (X - Y), can lay bii hai ciia Y tiic: -Y, sau do cpng X vdi -Y theo nguyen tic tren. Vidq: 97-52 =97+ (-52) +97 = 0110 0001 -52 = 1100 1100 45 =00010 1101 Bo qua Nhu v|iy, khi th\rc hign phep tinh tren sS thira ra mgt bit ngoai cimg ben trail, bit n2y s5 khong dugrc luu trong ket qua v2 s5 dugre bo qua. Nhin/chia s6 nguyin So vdi phep cgng vi phep trir, phep nhan va phep chia phtic tap horn nhieu. D)udi day chi gidi thigu phep nhan/phep chia vdi so nhj phan. Vi dp sau mo ta phep nihan hai so nhj phan: 1011 1101 1011 0000 1011 1011 (11 COSO 10) (13 CO so 10) 10001 111 ket qu2 143 trong co so 10 28 Chun ta c6 mpt so nhan xet sau; 1 Phep nhan tao ra cac rich rieng, moi tich thu dugc la ket qua cua vi?c nhan timg bit. 2 Cac ti'ch rieng de dang xSc djnh theo quy tSc: • Bit tuong ung so nhan la 1 thi tich rieng bang so bi nhan. • Bit tucmg iriig so nhan bang 0 thi tich rieng bang 0. 3 Tich dugrc tinh bang tong cdc tich rieng. Ph6p hia phuc tap hem phep nhan nhung d\ra tren cung mqt nguyen tie. H3y xem vi dp lu: bi chia 10010011 1011 001110 1011 ban dir rieng • -►001111 1011 1011 1101 so chia thuomg 100 phan du Ph^p hia vdi s6 nguyen se cho ket qua la thuong va phan du. 1.1.2.1. Bieu dien s6 thi^ a. Ngu6n tic chung De biu dien so thpc, trong may tinh nguoi ta dCmg ky phap dau phay dpng (Floaing Point N um ber). M pt cAch tong quat, m pt so thpe bieu d iln theo cAch nAy gom b thanh phan; N = M X r E Vdi K la phan djnh tri (Mantissa), R la ca so (Radix), c6n E la phan so mu (Expaent) Co sethudng duoc su dung la co so 2 hay co so 10, con M va E bieu dien theo kieu S) nguyen. Thpe te, ngudi ta chi can luu tru M va E. Vi du vdi CO SO R = 10, gia su hai so thpc N 1 va N2 duoc bieu dien theo phan djnh trj va 6 mu nhu sau: 29 Ml = -15 va El = +12 M2 = + 3 1 4 v aE 2 = -9 ConghTala Nl=MlxlO^' = -15 x 10'^= -15 000 000 000 000 va N2 = M2 X 10“ = 314 X 10-’ = 0.000 000 314 Nhu vay, bi6u dien so bang phan djnh trj vi phan so mu se gpn hon su dung giaa trj dung ciia so. Khi th\rc hi?n phep loan vdi so dau phay dpng s6 dupe tiln hanh tren ca sd cac : gia trj cua phan djnh tri va ph&n mu. Gia su c6 hai s6 dau phay dpng sau: N1 = Ml X r E' va N2 = M2 X r E2 FGii do, vi?c th\rc hi?n cac phep loan so hpe sS du(?c tien hanh: N1 ± N2 = (Ml X rEi-e2 ± m 2) x r “ , gia thiet E2 > El N1 X N2 = (Ml X M2) X r E'+e2 N1 /N 2 = (M1 /M2) X r E>-e2 Chu y; Vdi so th\rc bieu dien theo dau phay dpng tren : 32 bit 64 bit 80 bit dai gia tri tir 10“^* den 10*^*. dai gia tri tir 10"’®* den 10^’®*. dai gia tri tu 10"^®’^ den 10^®’^. Tir edng thuc tren, ta n h ^ thay ring each bieu dien nay khong bao gid cho gia i tri bang 0, vi the, c6 mpt so trudng hpp phai quy ude: • Neu tat ca cac bit cua E va M deu bang 0, thi N = ± 0. • Neu tat ca cac bit cua E = 1 va M = 0, thi N = ± oo. • Neu tat ca cac bit cua E = 1 va c6 it nhat 1 bit cua M = 1, thi N khdng pbhai la so. b. Chain IEEE 754/85 Vi?c bilu diln trong dau phay dpng theo chuan IEEE dupe hinh dung nhu sau: -2^ Co Exponent Mantissa (8 bit) d (23 bit) e 30 - Bit dau la 0 c6 nghia do la so duomg, ngugrc lai do la so am (Matissa sign). - Phin mu bieu dien trong ca so 2 va gia trj la gid tr) g6c cpng them 127. Tuy nhien, neu gia tri sau khi cpng Id 255 thi do khong phai la bidu dien so. - Phan djnh trj bieu dien dang so le nhj phan nho hon 1. Chii y; c6 str khac nhau giua bieu dien dau phdy dpng tren main frame : - Phan mu la 8 bit va gia tri ket qua dupe cpng them 127 vao phan goc. Phdn them ndy gpi la bias. - Phan djnh tri c6 23 bit va phan le nhj phan tuomg duomg vai phin dinh trj trir di 1 sS dupe luu. N6i each khac, so 1 khong bieu dien (bo). - Cp so phan mu dupe hieu la ca so 2. VI dp; So thpc +5 s6 dupe bieu dien nliu sau; 5io = 1012= IOI2 2“ = (1.01)2 2^ va phan djnh tri sSla 1.0l2-l2 = 0.0l2. NeilOh trupt phai 2 bit si tra thanh 1.012, 2"^ Ian tir gid trj ban dau. Vai mpe dich chun hoa, 2 dupe cpng them vao phan mu 0 va phan mu c6 gid trj Id 2. Do vay, khima phan mu Id 2 cpng them phan bias 127 si Id 129 vd mu biiu dien Id lOO'OOOh. 1.1 .:.5. Bieu dien ky tu> a. NiuySn tic chung Troig mdy tinh, ede ky tp cung can dupe chuyen doi thdnh chuoi bit nhj phan gpi Id ni ciia ede ky tp do. So bit diing cho moi ky tp theo ede md khde nhau Id khde nhai Bp md ASCII (American Standard Code for Information Interchange) dimg 8 ’ bit rd hoa cho mpt ky tp, con bp md Unicode dung 16 bit. Day Id hai bp md thong dpnj. Vi dp, vai bp md ASCII, chfr 'A' c6 md la 65 = 0100 0001. Ngai hai bp md tren, con c6 ede bp md khde; - H? thap phan md nhj phan BCD (Binary Coded Decima) dung 6 bit. • Hp thap phan md nhj phan ma rpng EBCDIC (Extended Binary Coded Decimal Interchange Code) dung 8 bit tuong duang 1 byte de bieu dien mpt ky tp. 31 b. mS ASCII ASCII 1^ bp mS dirpc dung de trao doi thong tin chuan cua My. Luc dau chi duung 7 bit (128 ky t\r), sau do ma rpng cho 8 bit va c6 the bieu dien 256 ky tpr khac rnhau trong may tinh. • Cdc ky tu hien thf thong dung: Cac ma tir 32 den 126 dung de m3 hoaa cho cac ky t\r hien thi thong d\ing, chia thanh ba nhom nhu sau: o C3c chur cai La-tinh, bao gom: 26 chu cai thuong tir a den z cco ma tir 97 d6n 122, 26 chu cai hoa tu A den Z c6 m3 tu 65 den 90. (Giiia chu cai thuong va chu cai hoa tuomg ting c6 ma chenh lech la 332. o Chu so thap phan: 10 chu so tir 0 den 9 dupe gan ma tu 48 d6n i 57. o Cac ky t\r khde: cac dau cham cau, cac phep toan, dau each,... • Cdc ky tic diiu khiin: 32 ky t\r dau tien ctia bang ma ASCII (c6 ma i tu 0 den 31) v3 m3 127 dung de m3 hoa cac thong tin di6u khiSn, dimg cho > viec chuySn nhihig thong tin den man hinh, may in, may tinh khac,... • Cdc ky tu ma rang: c6 m3 tir 128 d6n 255, ph\i thupc vao cac nha chee tao may tinh va phdt triSn phan mSm. Vi dp: bp ma mo rpng cua IBM edimg cho cdc may tinh dong IBM, bp m3 mo rpng ctia Apple dimg cho cac t may tinh Macintosh, bp m3 TCVN5712 c6 cac ky tu rieng cua tieng Viet. BANG MA ASCII voi 128 ky tu dau tien Hex 0 1 2 3 4 5 6 7 NUL DLE SP 0 @ P'p 0 0 16 32 48 64 80 96 112 SOH DCl ! 1 A Q a q 1 1 17 33 49 65 81 97 113 STX DC2 tl 2 B R b r 2 2 18 34 50 66 82 98 114 ¥ DC3 # 3 C s c s 3 19 35 51 67 83 99 115 ♦ DC4 $ 4 D T d t 4 20 36 52 68 84 100 116 32 5* NAK % 5 E U e u 5 21 37 53 69 85 101 117 6* SYN & 6 F V f V 6 22 38 54 70 86 102 118 7BEL ETB !7 G W g w 7 23 39 55 71 87 103 119 8BS CAN ( 8 H X h X 8 24 40 56 72 88 104 120 9HT EM ) 9 I Y i y 9 25 41 57 73 89 105 121 ALF SUB *J z jZ 10 26 42 58 74 90 106 122 BVT ESC + K [ k { 11 27 43 59 75 91 107 123 CFF FS i < L \ 1 1 12 28 44 60 76 92 108 124 DCR GS - = M ] m } 13 29 45 61 77 93 109 125 ESO RS > N A n - 14 30 46 62 78 94 110 126 SI US / 7 O 0 DEL F — 15 31 47 63 79 95 111 127 BANG MA ASCII v « 128 ky ke tiep Hex 8 9 A B C D E F 0c128E144a160 176L192JL208a224 240 1ii129ae1451161 177±193T209fi225±241 33 2e 6 1 T T r > 130 146 162 178 194 210 226 242 a 6 u 1 hIL n < 131 147 163 179 195 211 227 243 A3 6 fi — L £ f 132 148 164 180 196 212 228 244 sa 6 N =1 + F o J 133 149 165 181 197 213 229 245 5d ua^l h IT li -4- 134 150 166 182 198 214 230 246 7 9 u OTl \[ fT =: 135 151 167 183 199 215 231 247 8e 9 L 1IL + <6 o 136 152 168 184 200 216 232 248 9g 0 Jl ItJ 0 137 153 169 185 201 217 233 249 e U II JLrn 138 154 170 186 202 218 234 250 B1 ‘A Tl Tf 1 5 V 139 155 171 187 203 219 235 251 Qi £ % Ih ■00 n 140 156 172 188 204 220 236 252 Di ¥ iJl = 1 «P 2 141 157 173 189 205 221 237 253 EA Pis « =1 JLT 1 E ■ 142 158 174 190 206 222 238 254 F A / » 1■ n 143 159 175 191 207 223 239 255 c. 8$ m i Unicode Bdng m3 ASCII 8 bit vdi 256 gid trj khong the du cho de m3 h6a cac ky t\r cua cac ngon ngO dimg chil: tu(jfng hinh nhu drag Hdn, drag Nhat, H3n Quoc, Thdi Lan,... Tit tnrdc den nay, d3 c6 nhieu gidi phdp khdc nhau de m3 hod cdc ky ty cua cdc ngon ngCt nay tren mdy dnh. Tuy nhien, nhttng gidi phdp nay thubng diing ky thuat to h<7p ho^c cdc chuoi ky t\r dieu khien khd phirc t^p vd quan trgng hom cd Id cdc gidi phdp ndy khong tuong thich vdi nhau. Do d6, vi^c su d\mg dong then cdc 34 ngonngu trong cung mpt vSn ban va trong cimg mpt font chu thuomg 1^ khong thS hoicrat kho kh3n khi th\rc hi$n. Unicode ra doi de nh3m khSc ph\ic c3c nhirpc diem noi tren va xay dimg mot bo m3 chuan van n3ng dung chung cho tat ca mpi ngjn ngif tren the gidi, Unicode c6ng-xo6c-xi-om (consortium) dupe thanh lap v3o r3m 1991 nhu mpt to chuc phi Ipi nhuan nh3m phat triSn chuin Unicode, cac thail vien cua Unicode c6ng-xo6c-xi-om bao g6m cac cong ty hang dau the gioi trong ITnh vuc phin mem nhu Adobe, Aldus, Borland, Digital, GO, IBM, HP, Locus Metaphor, Microsoft, NeXT, Novell, Sun, Symantec, Taligent, Unisys, WorcPerfect, ... Unicode la bp m3 ky t\r 16-bit, tuomg thi'ch hoan toan vdi chuSn quocte ISO/IEC 10646-1; 1993. So c6 thi bieu dien 13 2“ . VcH 65.536 ky tp,Uiicode hau nhu c6 the m3 hoa tat ca c3c ngon ngG tren the gidi. Ngoai ra, vdi each; md rpng UTF-16, Unicode v3 chuin ISO 10646 c6n cho phep m3 hoa hon tripu ky tu m3 khong c3n ph3i dimg den m3 dieu khiSn Escape. Mft s5 dac diem cua Unicode: Mfi ky tp trong bang m3 Unicode deu c6 dp d3i c6 djnh la 16 bit, nhd do, vipc xu ly cacxdu ky tp Unicode rat dom gian, khong phuc tpp nhu cac giai phap dimg chuoi ky tp lieu khien, phai c6 nhung thuat to3n tuomg doi phuc tap de nhan di?n ky tp Uong mp chuoi cac Byte. Trong khi do, vcji Unicode, moi ky tp c6 dp dai dung hai Byte nerco the dmh vi r3t de dang cac vj tri cua ky tp trong chuoi Byte cho trude. Uncode tranh den muc toi da vipc djnh nghia du thira, trimg 13p. VI dp, ky tp 'e' chi CO mpt m3 duy nhSt dimg chung cho ca ngon ngu tieng Vipt, tieng Czech, ... Cuig chinh vi the nen hp thong chir tieng Vipt cd cac m3 n3m rai rac d nhieu vj tri khoig lien nhau. Tieng Han, Nhpt B3n va H3n Quoc cd kha nhieu ky tp trimg nhau nenchimg dupe dimg chung cho c3 ba ngon ngii, tuy nhien, trong Unicode van cd edevimg rieng dd djnh nghia nhiing ky tp d?c thii cua ba ngdn ngu nay. Unicode, vd lu b3n, kliOng quy dinh vipc bd tri c3c ky tp theo quy djnh s3p xep cua timg ngdi ngu, dieu nay cung la hp qua cua vipc tranh djnh nghia c3c ky tp du thira do pha tan dpng cac ky tp dimg chung nen khdng the bo tri cac ky tp theo timg vimg rieig cho timg ngdn ngu. Hom nfta, thpc te vdi nhieu ngdn ngft, ngudi ta ph3i dimg nhflig thupt toan rieng de s3p xep, chii khdng the s3p xep theo thu tp cua chung trotg bang chu c3i (tieng Vipt la mpt dien hinh). Uniode d3 dupe cai d3t trong c3c hp dieu hanh pho bien hipn nay. Muon sir dpng Uni ode can phai cd nh&ng phan mem ho trp hien thj ho3c cho phep gd ky tp theo chun Unicode, ngoai ra cung can phai cd font chu Unicode dupe cai d3t trong hp tidng. 35 Tieng Vi?t trong bo ma Unicode: Tieng Vi?t du(?c xep vao hp La-tinh md rpng 1 (Latin Extended 1). Tuy cac kyy tu tieng Vi?t phan bo khong tap trung, nhimg c6 mpt thuan Igri lom la tieng Viet dilute xep vao h{ vao-ra Moi thiet bj vao-ra lam nhi?m v\i chuyen doi thong tin tCr mpt dang vp ly n^o do ve d ^g dS li?u phu hpp vai may tinh ho3c ngupc lai. Cac thiet bi ngoai vi thong d\mg la bto phim, mta hinh, miy in hay mpt mdy tinh khdc. Nguiri ta c6 the phan z&c thiet bj ngo^i vi ra nhieu lo?i: - Thiet bi thu nhgn du li^u: bdn phim, chupt, mky quet inh,... - Thiet bi hien thi du li$u: man hinh, may in,... - Thiet bi nha: ckc loai 6 dia. - Thiet bi truyen thong: modem. - Thiet bi ho tria chi IP (Internet Protocol Address): Khi tham gia vdo internet, ede mdy tinh edn gqi Id host) phdi mang mgt dja chi IP dimg de nhan dang. Dja chi IP ndy Id luy nh4t vd dpi dipn cho chinh mdy tinh tham gia vdo mang internet. Dja chi IPv4 ;6m bon so thpp phan nW trong ddi 0-255 (c6n gqi Id Octet), phan edeh nhau bdi 54 lau chim. Moi so dugrc liru bai 1 byte IPv4 c6 ki'ch thu6c la 4 byte. VI du: 192.168.24.5, 172.16.0.4, ... IPv4 c6 khi ning cimg cap 2’^ (khoang hem 4 ti) dia :hi. Kho dja chi nay dang can kiet dan. Do do, d3 xuat hi?n IPv6 sir dyng 128 bit, lai gap4 Ian IPv4 (32 bit), nen c6 kha n3ng cung cap 2'^* dia chi. Dja chi IP c6 the le danf bi phat hi?n ra, ngucri ta c6 the lay du(jrc dja chi IP m3y tinh cua ban khi lirct qua mqt trang web, hay khi bm a tren IRC (Internet Relay Chat, mpt dang ten l(ic cap toe qua mang), tren ICQ (cqng dong I Seek You), ho3c khi bm ket noi /6i mpi ai do, neu ai do gui cho bM mpt email voi mpt doan m3 java tom IP,... H4 thor.g ten mien DNS (Domain Name System): Do nguoi six dpng kho c6 the nho dupe chuoi so IP kha dai nay, vi the, ben c^uth dja chi IP bao gio cung c6 them mpt edi ten mang mpt y nghia nao do de nha gpi la ten mien. Nguoi ta xay dpng h? thong dia chi internet, gpi la hp thong ten mien DNS, de d§t ten cho cac host tren internet. Vi du; www.dantri.com.vn. www.soict.hut.edu.vn. www.google.com.vn. www.bbc.co.uk. www.voutube.com. www.facebook.com.... Moi host tren internet c6 hai dia chi: dja chi IP vd dja chi ten mien dupe dnh xa voi nhau. Khi ngudri dung su dpng ten mien, no s6 dupe dnh xa sang dja chi IP tuong ung. Ten mien dupe phan lam ba nhom: ten mien quoc te, ten mien quoc gia, ten mien thii cap. Ten mien quoc te va ten mien quoc gia cap 1 do t6 chiic Internet Corporation for Assigned Names and Numbers (viet tit la ICANN) qudn ly. Ten nien quoc gia cap thap hem do ca quan quan ly ten mien cua timg nuac quan ly. 6 Vipt Nam, co quan quan ly ten mien quoc gia la Trung tarn Internet Vipt Nam (VNNIC) trpe thupc Bp Thong tin va Truyen thong. Ten mien Id dja chi duy nhat tren htemet nen khong bao gia c6 sp trung nhau. Khdch hang d3ng ky la ngudri c6 toan iiuyen so huu ten mien. Ten mien khi dupe d3ng ky, thuemg c6 gid trj trong mpt Ihoang thdri gian nhat djnh, sau d6, neu khdch hang tiep tpc c6 nhu cau sir dpngthi phdi lam ede thu tpc gia h?n. Ten nien quoc te la ten mien c6 phan duoi la com, edu, net, org, gov, int, mil, biz, info, ic, pro. 55 Ten Mo ti .com Danh cho to chiic,doanh nghiep, ca nhan hpat dong thucmg mai. .edu DM i cho cic C0 quan, to chuc, doanh nghiep c6 boat dpng lien quan toi giio d\ic, dao tao. .net Diinh cho cdc ca quan, to chuc, doanh nghipp th\rc hipn chuc nSng ve mang noi chung. ■org Danh cho cdc to chuc chinh tri, x5 hpi va cac ca quan, to chuc, doanh nghipp CO ho?it dpng lien quan den llnh v\rc chinh trj, xa hpi. •gov Danh cho cdc co quan, to chuc thupc bp mdy nha nude a trung uomg va dja phuang. .int Ddnh cho cdc to chuc quoc t l .mil Danh cho quan su (Hoa Ky). .biz Danh cho cdc t6 chuc, doanh nghipp, cd nhan kinh doanh, tuong duomg vdi " .com" .info Ddnh cho cdc to chuc cting cap cdc nguon dOr lieu thong tin ve cdc Imh v\rc kinh te, chinh tri, van hoa, x3 hpi va cdc ca quan, to chuc, doanh nghipp lien quan tdi ITnh v\rc cung cap cdc nguon du lipu thong tin va thong tin cd nhan. .ac Ddnh cho cdc to chuc nghien cuu va cdc ca quan, to chiic, doanh nghipp c6 boat dpng lien quan tdi ITnh vpre nghien cuu. .pro Ddnh cho cdc to chuc, cd nhan ho^it dpng trong nhung ITnh vyc cd tinh chuyen ngdnh cao. 56 .health Danh cho cac t6 chuc y te, dugrc phim va cac co quan, to chuc, doanh nghi?p CO boat dpng lien quan tdi ITnh nrc y te, dupe pham. .name Danh cho ten rieng ciia ca nhan tham gia boat dpng Internet. Ten mien qu6c gia la ten mien c6 phan duoi la ky hipu ciia moi quoc gia: vn (Vipt Nam), cn (Trung Qu6c), tw (Dai Loan), kr (Han Qu6c), jp (Nhat Ban), au (Uc), uk (Anh), ve (Venezuela), fr (Phap), ca (Canada), us (Hoa Ky), de (Dire), ru (Nga),... Ten mien cap 2 cua cac qu6c gia do to chuc quan ly mang internet cua quoc gia do djnh nghia, c6 thS djnh nghia khac di, nhieu len hay It di, nhung thong thuemg cac quoc gia van dinh nghia cac ITnh v\rc tuong t\r nhu cac ITnh vyc diing chung neu tren. Vi du: .com.vn, .edu.vn, .net.vn, .org.vn, .gov.vn,... Dirdrng dan URL: URL, viet tit ciia Uniform Resource Locator, dupe diing de tham chieu tdi tai nguyen tren internet. URL mang Ipi kha nSng sieu lien ket cho cac trang m ^g. Cac tai nguyen khac nhau dupe tham chieu tdi bing dja chi, chinh la URL. Mpt URL c6 nhieu thanh phan, quan sat vi du sau: http://video.google.co.uk:80/videoplay?docid—724692761280&hl=en#00h02m30 Day la cac thiinh phan chinh cua URL nay: • Giao thuc la http. Ngoai ra con c6 nhieu giao thuc khac nhu https, ftp,... • Ten host hay hostname la video.google.co.uk. • Ten mien thu cap la video. • Ten miSn chinh la google.co.uk. • Ten mien cap 1 (top-level domain) lit uk.Ten mien uk 1^ ten mien quoc gia. • Ten mien cap 2 (second-level domain) la co.uk. • Cong giao tiep la 80, day la cong ngam djnh ciia djeh vy Web. Co the sii dyng cac cong khde nhu 8080 hay 8000. Khi cong la 80, phan Idn ngudi ta khdng can them vao dudng dan. 57 N hi cung cap truy cap Internet (Internet Access Provider - lAP): La nha cung cap dich vy duong truyen de ket noi voi internet, qu^n ly cong ket noi vdri quoc te. Vi dy: d Vift Nam c6 Cong ty Di?n todn v i Truyen so li$u VDC. Nhi cung c4p djch vy internet (Internet Service Provider - ISP): La nha cung cap cac djch vy internet cho c^c to chuc, ca nhan. ISP phai thue dudmg truydn va cong ciia lAP. Vi dy; d Vi?t Nam cd VDC, FPT, Viettel. 1.2.3. Givi thifu dieu hanh i.2.3.1. Cac khai ni^m co> ban a. K h il nl$m h$ d/du hdnh Hy dieu hanh la myt trong cdc phan mem hy thong cd tinh phd dyng. Cd nhieu each dien dyt khde nhau ve h? dieu hinh xuat phat tvr gdc dp ciia nhiing ngudi sir dyng khde nhau. Tuy vay cd the dien dat nhu sau: H( diiu hdnh la h( thong chircng trinh dam bao qudn ly tdi nguyen cua hf thong tinh todn vd cung cap cdc dfch vp cho ngudi su dfing. Thong thudng trong cdc may tinh hipn nay, hp dieu hanh dupe edi dSt trdn dla. Nhipm vy cy the hem cua hp dieu hanh la; • Khdi dpng may tinh, tyo mdi tnrdng giao tiep cho ngudi su dyng. • Ty dpng dieu khien vd kiem soat boat dpng cua cac thiet bj (6 dla, bdn phim, mdn hinh, miy in,...). • Qudn ly vipc cap phdt tdi nguyen cua mdy tinh nhu bp xii ly trung tarn, bp nhd, cdc thiet bj vdo ra... • Qudn ly cdc chuomg trinh dang thyc hipn tren mdy tinh. • Thyc hipn giao tiep vdi ngudi su dyng de nhan Ipnh vd thuc hipn Ipnh. Hp dieu hdnh Id phAn mem hp thong, vi vyy nd phy thupc vdo c4u tnic cua tndy tinh. Moi loyi mdy tinh cd h$ dieu hdnh khde nhau. Vi dy: + Mdy tinh Idn IBM360 cd hp dieu hdnh DOS, TOS. 58 + May ti'nh Ian E C -1022 c6 h? dieu hanh OC-EC. + May ti'nh ca nhan PC-IBM c6 h? dieu hanh MS-DOS. + Mang mdy ti'nh c6 cdc h? dieu hanh mang NETWARE, UNIX WINDOWS-NT... b. T^p (File) T?p (con g(?i la tap tin hay t?p tin) la t|p hpp cac dS li?u c6 lien quan vdri nhau vi dugrc to chiic theo mpt cau true n^o do, thuomg dugc luu tru ben ngoai may ti'nh. Npi dung ciia t?p c6 the la chuomg trinh, dO li?u, vSn ban,... Moi tap tin dugre lui len dTa vdi mpt ten rieng phan bigt. Moi hg dieu hanh c6 quy ude dSt ten khac nhau, ten tap tin thudng c6 hai phan: phan ten (name) va phan md ronf (extension). Phan ten la phan bit bugc phdi c6 ciia mgt t(ip tin, c6n phan md rgnj thi CO the c6 hoSc khong. • Phan ten: Bao gom ede ky t\r chu tir A den Z, cac chir so tir 0 den 9, cac ky t\ khac nhu #, $, %, ~,@, (,), !, _, khoang tring (ten tgp tren DOS khong cc khodng tring). Phan ten do ngudi tao ra t|p tin ddt. Vdi MS-DOS, phan ten c( toi da 8 ky tyr, vdi Windows phan ten cd the d(it toi da 128 ky t\i. • Phan md rgng: Thudng dung 3 ky tu trong cac ky t\r neu tren. Thonj thudng phin md rpng do chuomg trinh ung dying tao ra tap tin t\i ddt. • Gida phan ten vd phan md rgng cd mgt dau cham (.) ngdn edeh. Ta c6 the edn cu vao phan md rpng de xdc dinh kieu ciia file: COM. EXE : Cdc file khd thi chay true tiep dupe tren hg dieu hanh. TXT, DOC,... : Cdc file vdn ban. PAS, BAS,... : Cdc file chuang trinh PASCAL, DELPHI, BASIC,... WKI, XLS,...: Cdc file chuang trinh bdng ti'nh LO'TUS, EXCEL ... BMP, GIF, JPG,...: Cdc file hinh dnh. MP3, DAT, WMA, ... : Cdc file am thanh, video. 59 Ky hi^u dai di?n (Wildcard) De chi mQt nhom cac tap tin, ta c6 the su dyng hai ky hi?u dai dien: + Dau ? dung de dai di?n cho mpt ky t\r bat ky trong ten tap tin tai vi tri no xuat hi?n. + Dau * dung de dai dien cho mpt chuoi ky t\i bat ky trong ten tap tin tir vj tri no xuat hi?n. Vi dp: Bai7.doc Bail.doc, Bai6.doc, Baiq.doc,... Bai*.doc Bai.doc, Bai6.doc, Bail2.doc, BaiTap.doc, ... BaiTap.* BaiTap.doc, BaiTap.xls, BaiTap.ppt, BaiTap.pdf, ... Lieu y: nen dat ten mang tinh g(ri nha. c. Quin ly t^p cua d iiu hinh Cdu true dia tie Hp thong dia tir gom nhieu mSt (side) gin so hipu la 0, 1,... Ve mat logic, moi mat dTa CO mpt dau ghi/dpe (header), doi khi ngucri ta con dong nhat hai khai nipm nay. Moi mat chia thinh cac r3nh (track - ckc dudmg tron dong tarn). Cac ranh dupe dinh so tu ngoAi v^o trong bit diu tu 0. Moi ranh chia thanh ede cung (sector), moi cung thong thuong c6 dung lupng 512 byte. Mpt tir tr\i (cylinder) gom cac ranh c6 ciing ban kinh nim tren ede mat dTa khac nhau. To chiec ghi thong tin tren dia Thong tin luu trCt tren dTa dudi dang ede tpp. Moi tpp chiem mpt hodc nhieu sectors tuy dung lupng tpp. De thuan Ipi cho vipc quan ly tpp, hp dieu hanh cho phep chia dTa thanh ede viing, moi viing chia thanh ede viing con....Moi vimg c6 mpt viing con rieng de luu tru thong tin vi viing do, viing con ndy dupe gpi Id thu mpe (Directory). Tpp dupe luu tru a ede viing, vi vay ta c6 the thay t6 chuc luu triT nay c6 dang cay (Tree). Vi dp: 60 Hinh /. 10. Cay phan cap thw ntftc Thir muc la nai liru giCr cac tap tin hoac thu muc con theo mot chii de nao do theo y nguoi sir dung. Day la bi|n phap giiip ta quan ly dugrc t$p tin, de dmg tim kiem chung khi can. Cac tap tin c6 lien quan voi nhau c6 the ducjfc xep trong eiing mpt thu mqc. Sau day la bieu turyng cua thu mpc hay con gpi la Folder trong Windows: Tren moi dTa c6 mpt thu muc chung gpi la thu mpc goc. Thu mpc g6c khong c6 ten rieng va dupe ky hipu la \ (dau x6 phai; backslash). Dudi moi thu mpe g6c c6 cac tpp tin trpe thupc va cac thu mpe con. Trong ede thu mpe con cung c6 cac tap tin true thupc va thu mpe con cua no. Thu mpe chiia thu mpe con gpi la thu mpe cha. Thu mpe dang lam vipc gpi 14 thu mpe hipn hanh. Ten cua thu mpe tuan thu theo caeh dSt ten ciia tap tin. Cdch xdc dirth ten day du cua t^p Ten tep day du gom nai luu tru tep - duong dan tir goc den tep (Path) va ten tep Duong dan dupe chi ra nhanh cay thu mpe chua tpp, trong do su dpng ky hipu "\' ng4n cdch ten cae thu mpe . Vi dp : C:\TC\BIN\BI.C 61 H§ di6u hanh'diKjrc phan chia thanh cac phan, phu hgp vdri cac chiic nang rieng ciia cong vi?c. Nhirng phan nay dugrc luu tren dTa duai dang cac t?p (File). Vi dp: H? dieu hanh MS-DOS gom tap cac t?p, trong do c6 ba tpp co ban: + MSDOS.SYS - t?p hp thong quan trqng, chua nhan hp dieu hanh. + 10.SYS - t?p dieu khien vio ra. + COMMAND.COM - tfp l?nh. 1.2.3.2. Ifnh cua dieu hanh • Thao tac vdi t?p: sao chep, di chuyen, xoa, doi ten, xem npi dung tep. • Thao tie vdri thu mpe: tpo, xod, sao chep. • Thao tic vdri dia: t^o khuon (Format), sao chep dTa. 1.2.3.3. Hf di4u hanh Windows a. Sfr ra dai v i p h it triin Windows li mpt bp chuomg trinh do hing Microsoft san xuat. Tu version 3.0 ra doi vio thing 5 nim 1990 dm nay, Microsoft di khong ngimg cii tien lam cho moi tnrdmg nay ngay cang dupe hoin thipn. Windows 95: Vio cuoi nim 1995, a Vipt Nam, d i xuat hipn mpt phien ban mdri cua Windows m i chiing ta quen gpi li Windows 95. Nhihig cii tien mdi ciia Windows 95 dupe tdm tit nhu sau: - Giao dipn vdri nguoi su dpng dupe thiet ke lai hoin toin nen vipc khdri dpng cic chuomg trinh ung dpng ciuig cic cong vipc nhu mdr vi luu cat cic tu lipu, to chuc cic tii nguydn trdn dTa vi n6i k6t vdri cic h§ phpc vp trdn mang - tit ci deu tro nen dom giin v i de ding hem. - Cho phep dit ten cho cic tap tin dii den 255 ky tp. Dieu niy rat quan trpng vi nhumg ten dii s6 giiip gpi nhdr den npi dung ciia t|p tin. - Ho trp Plug and Play, cho phdp tp dpng nhan dipn cic thiet bj ngopi vi nen vipc cii dit vi quin ly trd nen dem giin horn. - Ho trp tot horn cho cic ung dpng Multimedia. Vdri sp tich hpp Audio vi Video ciia Windows 95, miy ti'nh ci nhan tr6 thinh phuemg tipn giii tri khong the thieu. 62 - Windows 95 la he dieu hanh 32 bit, vi vay no tang cuong S tic manh va kha nang van hanh len rat nhieu. - Trong Windows 95 c6 cac cong cu da duoc cai tien nham chuSn hoa, t6i ini hoa vd dieu chinh cac svr c6. Dieu nay giiip ban yen tarn hoii khi lam vi^c vai may vi tinh trong moi tnjong cua Windows 95. Tom lai, vdi nhimg tinh nang mdi uu viet va tich hop cao, Windows 95 da tro thanh moi tmbmg lam vi$c dugtc nguoi sir d^ng ua chupng va tin dung. Windows 98, Windows Me: La nhtmg phien ban tiSp theo cua Windows 95. Nhung phien ban nay tiep tyc phat huy va hoan thipn nhCmg ti'nh nSng im viet ciia Windows 95, dong thoi tich h hoc eon _ ^ Q Go DatBMod |(^ Dosktop 9 My Ooofnonts 9 9 MyCofloputor a j i )VkFteppy(A>) 9 SYSTEM (C:) a <^DATA(D:> 9 QBOALANDC 9 QCh«nmM(2 200>-20(H \ a ChamtNMC32003*2004 |(^ do thKHU 2009-2004 (^DUnh t t O o e trtnh Internet S GtooMlh £ BomonHoa fi I^En^ 3 Qoo bmNyttiuyot ^SQLSorvw TMhoc AJkcess S Tkilw.A.P«M^ TkthocB Beall.l.lWiJ.UOgi, ^KBao b M ph»i Intamot ^gloe trinh phon PowwfoM O Q w trinh phan Woid nang c«o ^OaotrWtMMows ^TMiocA IBM TAP IBM TAPEXCa TAP_THAN DU UeU EXCEL |CH5 jcH6 jcHU0MGl_2 ICHJONG9.4 jcHUOMSS |OtJONG6 iQOITKKUJtJCUIC |GT TWCB.COmfTE |GT Tin hoc can ban |GT Tlr> hoc can banI |GT Tin hoc can ban.phan n be 452 »S 167 KB 791KB 1J76KB I.02CKB 537 KB 421KB 1,224 KB 1,024 KB SSKB 4,46CKB 4,517 KB 3,01S KB 6.322 KB 43 KB 2CKB PlaFoldv naFokkr na Folder Mkrosoft Word Doc.. Ncroeoft Word Doc.. McroaoTt Word Dec.. Woosoft Word Doc.. Mcrosoft Word Doc.. Mcrosoft Word Doc.. Mkrosoft Word Poe.. Mcrosoft Word Doc., f ^ o soft Word Doc.. Mkrosoft Word Doe.. Mcrosoft Word Doe.. Mkrosoft Word Doc.. Mkrosoft Word Doc.. Mcrofoft Word Doc.. Meroceft Word Dec.. Mcrosoft Word Doe.. 9/9/2004 9/B/2004 2 9/B/20D4 2 9/9/2004 9/6/2004 5 6/2/2004 2/3/20044 2/9/iOCH 9 2/5/20049 2/5/20049 9/6/2004 1 2/5/20049 2/3/20045 2/3/2004 7 11/30/200 9/6/2004 3 9/7/2004 0 9/9/2004 1 9/8/2004 2 2/5/20049 9/7/2004 0 Hinh 1.16. Cura so Windows Explorer 74 Thirmuc (Folder) - Back; Chuyen ve thu muc truac do. - Up: Chuyen len thu mge cha. I©:- - Forward: Chuyen toi thu muc vira quay ve (Back). - Search; Tim kiem tap tin/ thu muc. {^Folders - Folder: Cho phep an/ hign cua so Folder ben trii. [HU Thumbnails TSes Icons List • Details - Views: Cac che do hien thj cac doi tugmg (tap tin/thu muc/6 dia) NqI dung trong cira so c6 the dirge s3p xep the hien theo thu tg. Doi voi kieu th hi?n Details, ban c6 the thgc hi?n bSng each luan phien nhan chugt len cpt tuom ling (Name, Size, Type, Date Modified). Trong cac kieu the hien khac bgn c6 the thgc hipn Ipnh View/Arrange Icons By v Iga chgn tiep mgt trong cac khoa sip xep (theo ten, kich co t|p tin, ki6u tap tir ho5c ngay thang cap nhat). Trong kieu the hipn bing ede bieu Urgng Ion va bieu tugng nho, ban c6 thS d Windows sip xep tg dgng bing Ipnh VIew/Arrange Icons By/Auto Arrange. Tu chgn Auto Arrange chi ap dung cho ciia so cua thu mge hien h^nh. 75 Thao tic vM thv myc v i typ i. M& tap tin/thu muc Co ba each th\rc hi?n: • Cdch 1: D_Click len bieu tucjrng cua tap tin/thu myc. • Cich 2: R Click len biSu tugmg cua tap tin/thu myc va chyn myc Open. • Cdch 3: Chpn tap tin/thu myc v4 nhan phim Enter. Neu tap tin thuyc loai typ tin vSn ban thi chuong trinh ung dyng ket hop s5 duac khdi dpng va tdi li?u se dupe nap v^io. Trong tnrdng hpp chuomg trinh ung dyng khong dupe cai dat trong may tinh thi Windows se md hpp tho^ii Open With vd cho chpn chuomg trinh ket hpp. Neu tap tin thupc dang chuong trinh ung dyng thi chuong trinh tuong ung se dupe khdi dpng. ii. Ch(>n tgp tin/thu muc • Chpn mpt tap tin/ thu myc; Click len bieu tupng tap tin/thu myc. • Chpn mpt nhom tap tin/ thu myc: Co the thyc hipn theo hai each: — Cdc doi tupng can chpn la mpt danh sdeh gom c&c doi tupng lien tyc: Click len doi tupng dau danh sich de chpn, sau do nhan giO phim Shift va Click len doi tupng 6 cuoi danh sdeh. — Cdc doi tupng can chpn nim rdi rye nhau: Nhan giu phim Ctrl va Click chpn cac doi tupng tuong ung. Hi. Tqo thu muc • Chpn noi chiia thu myc can tyo (thu niyc/6 dTa 6 cua so ben trai). • Chpn menu File/New/Folder ho(ic R_Click/New/ Folder. • Nhyp ten thu myc mdi, sau d6 g5 Enter de ket thuc. iv. Sao chip thu muc va tgp tin Chpn ede thu myc va typ tin can sao chep. Sau d6 c6 the thyre hipn theo mpt trong hai edeh sau: 76