Eminyakeni embalwa edlule, umbhali wavakashela imakethe yezeze ephethwe yi-W6TRW endaweni yokupaka izimoto eNorthrop Grumman eRedondo Beach, eCalifornia. Phakathi kwama-TV amise okwebhere elimhlophe kanye nenqwaba yamashaja efoni nezinto zikagesi kwakukhona ibhokisi lepulangwe elinengidi, isibambo sokhuni, nesixhumi se-DB-25 eceleni. Eduze kwesixhumi kukhona iswishi: i-half duplex - i-duplex egcwele. Umbhali waqonda ukuthi kuyini. Imodemu. imodemu yokhuni. Okungukuthi, imodemu ehlanganiswe ngokuzwakalayo ekhishwe yi-Livermore Data Systems cishe ngo-1965.
Imodemu isesemakethe yezimoto. Ngokushesha ngemva kokuthatha izithombe, umbhali wayithenga ngo-$20.
Njengoba kungeyena wonke umuntu owaziyo ukuthi iyini imodemu ehlanganiswe ngokuzwakalayo, ukuhlehla okuncane emlandweni. Inkinga yayiwukuthi kudala, kwakungewona olayini kuphela ababeyimpahla yezinkampani zezingcingo. Kwadingeka baqashe namasethi ezingcingo. Labo bafundi abathole i-daylap baxhumanisa amamodemu ngqo nezintambo zocingo. Futhi-ke, lapho lemodemu yenziwa, yayinqatshelwe ukwenza kanjalo. Ngokomthetho waseMelika we-1934, kwakungenakwenzeka ukuxhuma noma yini ocingweni lwasekhaya nganoma iyiphi indlela nhlobo. Ngo-1956, ngemva kweHush-A-Phone Corp v. Umthetho wase-United States wehlisiwe: ngomshini kwaba nokwenzeka ukuxhuma. I-Hush-A-Phone .
Kwavunyelwa ngokusemthethweni ukuxhuma amadivaysi ahlukahlukene ocingweni ngogesi e-USA ngo-1968 (). Kodwa kuze kube ngu-1978, leli thuba alikwazanga ukusetshenziswa, njengoba amanani, imininingwane kanye nezindlela zokuqinisekisa azizange zithuthukiswe. Ngakho-ke, kusukela ngo-1956 kuya ku-1978, kwaba nengqondo ukusebenzisa amamodemu e-acoustically interface kanye nemishini yokuphendula. Eqinisweni, bakhululwa isikhathi eside - nge-inertia.
Le modemu, manje emi etafuleni lombhali, iyikhasi elibalulekile kodwa elingajwayelekile emlandweni. Yandulela isixazululo seCarterphone ngakho-ke ayikwazi ukuxhuma ngqo kunethiwekhi yocingo. Yaklanywa ngaphambi kokuthuthukiswa kwama-chips amaningi athathwa njengakudala namuhla. Inguqulo yokuqala yale modemu ikhishwe ngonyaka nje ngemva kwe-Bell 103, imodemu yokuqala ephumelele kwezohwebo. Nasi isibonelo esihle sokuthi mangaki amathuba angakhanywa kuma-transistors ayishumi nantathu. Khona-ke le modem yakhohlwa isikhathi eside, kwaze kwadutshulwa amavidiyo amabili ngayo, eyodwa ngo-2009, enye ngo-2011:
I-blogger yevidiyo i-phreakmonkey ithole ikhophi yokuqala yemodemu enenombolo ye-serial engaphezudlwana kuka-200. Amamodemu anjalo ahlukaniswa ngamakesi we-walnut, izingxenye zawo ezixhunywe ngamajuba. Ngokusho kwe-phreakmonkey, lesi sici singasetshenziswa ukucacisa ukuthi imodemu indala kangakanani, ngoba ama-dovetails asebenza kanzima. Kusukela ngenombolo ye-serial 850, amamodemu aqala ukufakwa emacaleni ezinkuni ze-teak ngokuxhunywa kwamabhokisi. Khona-ke izitho zomzimba zaqala ukuxhunyaniswa nezilimi. I-Livermore Data Systems iyadingeka ukwenza amamodemu asheshe futhi asheshe.
Ngo-2007 i-blogger u-Brent Hilpert wabheka imodemu enjalo futhi . Isikimu sakhe sithakazelisa ngokukhethekile. Wonke ama-transistors ayishumi nantathu kumodemu ayesezingeni futhi esakazeke ngaleso sikhathi. I-germanium PNP transistor eyodwa yasetshenziswa lapho ngesizathu esingacacile kumbhali. Ama-Transistors azo zonke lezi zinhlobo kuselula ukuwathola esitokisini esidala namuhla. Cishe amadola angamashumi amabili kuphela - futhi ezandleni zakho isethi ephelele yama-transistors adingekayo ukuphinda imodemu efanayo. Yiqiniso, kuyodingeka eminye imininingwane, kuhlanganise nama-miniature transformers.
Empeleni, othile ukhiphe idivayisi yesixhumi esibonakalayo se-acoustic kumodemu, okunye kuhambisana ngokugcwele nemibhalo. Kunamabhodi amathathu ku-backplane. Okokuqala - yonke imininingwane ye-PSU, ngaphandle kwe-transformer, kwesibili - i-modulator, okwesithathu - i-demodulator. Ama-transistors angu-2N5138 angowakamuva: Isonto lama-37, 1969. Kwakungenakwenzeka ukucacisa ngokunembile usuku lokukhishwa kwemodemu ngokwayo, kodwa cishe yakhiqizwa futhi yathunyelwa ngaphambi kuka-1970.
Ukuxhumana kolimi ne-groove kusho imodemu ephume sekwephuzile
Umbhali uthenge le modemu ukuze nje ayigcine ekhaya. Lena imodemu yokhuni, kodwa cishe akekho owazana nomlobi ocabanga ukuthi upholile kangakanani. Lena into yobuciko, lapho kunezinto eziningi ezingavamile. Umbhali wayefuna ukukulungisa, kodwa wabona ukuthi kwakungenakwenzeka.
Okokuqala, ngenxa yalokhu udinga ukuthola insiza yokuqala ye-acoustic interface. Ngenxa yokungabikho kwayo, abavakashi bemakethe yezeze babengaqondi ukuthi hlobo luni lomshini owawuphambi kwabo. Ilogo ye-Livermore Data Systems kanye nenombolo ye-serial bekukhona kule divayisi ekuqaleni, futhi manje ukungabi khona kwabo kwenza kube nzima kwezinye izivakashi ukuthi zibone izimpahla njengemodemu, ngoba azizona izisebenzi zamamyuziyamu wekhompyutha. Kuyalinga, yebo, ukuphrinta imininingwane yedivayisi ye-acoustic interface, kodwa ingabe izandla zizofinyelela kuleli phuzu?
Okwesibili, imingcele yama-capacitor amaningi ngokuqinisekile "yantanta" kuyo. Yiqiniso, kuyathakazelisa ukuthatha nokuhlunga kuwo wonke amabhodi, kodwa uma umbhali efuna ukuthola imodemu esebenzayo nge-acoustic pairing, kunenketho engcono.
Lona umklamo ohlakaniphile obizwa ngokuthi "", eyasungulwa yi-Chaos Computer Club ngo-1985 ngokuphendula ukuvinjelwa okufanayo, okwaqhubeka nokusebenza eJalimane. Imodemu enjalo ilula, futhi inamathuba amaningi. Yenziwe ku-chip ye-AM7910, isatholakala ngezikhathi ezithile ethengiswayo, futhi isebenza ngesivinini esifika ku-1200 baud. Kungenzeka ukwakha imodemu kusuka ekuqaleni kuyo ngokushesha kunakuma-transistors ahlukene.
Ngokuvamile, asikho isidingo sokubuyisela le modem yokhuni, kodwa kwaba mnandi kakhulu ukuyiqaqa, ukuhlela isithombe sesithombe bese ubuyisela konke ndawonye njengoba kwakunjalo. Cishe wonke ama-electronics ayebukeka kanje ngaphakathi, kuze kube yilapho kukhona ama-microcircuits kuwo. Kodwa uma ngokuzumayo umbhali ehlangabezana nedivayisi ye-acoustic interface efanelekile kule modem, yena, yebo, uzophinde acabange: mhlawumbe kusafanele ukuthatha ukulungiswa?
Source: www.habr.com