VAX

**VAX** shine tsarin koyar da CISC da aka kafa gine-gine (ISA) da layin manyan injiniyoyi da wuraren aiki wanda Kamfanin Kayan Kayan Dijital (DEC) ya haɓaka a tsakiyar 1970s. VAX-11/780, wanda aka gabatar a ranar 25 ga watan Oktoba, a shekara ta 1977, shi ne na farko na kewayon mashahurai da manyan kwamfutoci masu aiwatar da VAX ISA. Fiye da samfura 100 aka gabatar a tsawon rayuwar ƙirar, tare da membobin ƙarshe da suka isa farkon  shekarar 1990s. DEC Alpha ya ci nasarar VAX, wanda ya haɗa da fasali da yawa daga injin VAX don sauƙaƙe ɗaukar hoto daga VAX.

An tsara VAX a matsayin wanda zai maye gurbin 16-bit PDP-11, ɗaya daga cikin mafi ƙarancin minicomputers a cikin tarihi tare da misalai kusan 600,000 da aka sayar. An tsara tsarin don bayar da jituwa ta baya tare da PDP-11 yayin da ake fadada ƙwaƙwalwar zuwa cikakken aiwatar da 32-bit da ƙara buƙatun da aka tsara ƙwaƙwalwar ajiya . Sunan VAX yana nufin *manufar "Virtual Address eXtension* " wanda ya ba da damar shirye-shirye su yi amfani da wannan sabon ƙwaƙwalwar ajiyar yayin da har yanzu suna dacewa da lambar PDP-11 da ba a canza ba. An zaɓi sunan "VAX-11", wanda aka yi amfani da shi a farkon samfuran, don haskaka wannan damar.

Daga baya samfuran a cikin jerin sun yi watsi da alamar -11 kamar yadda jituwa ta PDP -11 ba ta zama babbar damuwa ba. Layin ya faɗaɗa zuwa manyan injina biyu kamar VAX 9000 har ma da tsarin aiki -scale kamar jerin VAXstation . Iyalin VAX a ƙarshe sun ƙunshi zane -zane iri daban -daban da sama da samfuran mutum 100 gaba ɗaya. Duk waɗannan sun dace da junansu kuma galibi suna gudanar da ingantaccen tsarin aikin VAX/VMS .

VAX an gane da matsayin quintessential CISC ISA, tare da manya-manyan yawan jama'ar-harshen-shirye-shiryen-friendly magance halaye da kuma inji umarnin, sosai orthogonal gine, da kuma umarnin for hadaddun ayyukan kamar jerin gwano sa ko shafewa, yawan tsarawa, da kuma polynomial kimantawa. 

## Suna

Sunan "VAX" ya samo asali ne a matsayin acronym na *Virtual Address eXtension*, duka saboda an ga VAX azaman ƙara 32-bit na tsohuwar 16-bit PDP-11 kuma saboda (bayan Firayim Minista ) farkon mai ɗaukar ƙwaƙwalwar ƙwaƙwalwa don sarrafa wannan babban adireshin sarari.

Siffofin farko na injin VAX suna aiwatar da "yanayin dacewa" wanda ke kwaikwayon yawancin umarnin PDP-11, yana ba shi 11 a cikin VAX-11 don haskaka wannan jituwa. Sigogin baya sun sauke yanayin dacewa da wasu daga cikin umarnin CISC da ba a yi amfani da su ba don kwaikwayon software na tsarin aiki.

## Saitin koyarwa
An tsara saitin umarnin VAX don zama mai ƙarfi da daidaituwa .  Lokacin da aka gabatar da shi, an rubuta shirye-shirye da yawa cikin yaren taro, don haka samun tsarin koyar da "mai son shirye-shirye" yana da mahimmanci.   Da shigewar lokaci, yayin da aka rubuta ƙarin shirye-shirye a cikin harshe mafi girma, tsarin koyarwar ya zama ba a bayyane, kuma abin da ya fi damun shi shine marubutan tattarawa.

Aspectaya daga cikin abubuwan da ba a saba gani ba na saitin umarnin VAX shine kasancewar abin rufe fuska  a farkon kowane ƙaramin shirin.  Waɗannan su ne tsarin saɓani na sabani wanda ke ƙayyade, lokacin da aka ba da iko ga shirin ƙasa, wanda za a kiyaye rajista. Tun da abin rufe fuska rajista ne nau'in bayanan da aka saka a cikin lambar aiwatarwa, za su iya yin saɓin layi na lambar injin da wahala. Wannan na iya rikitarwa dabarun ingantawa waɗanda ake amfani da su akan lambar injin. 

## Tsarin aiki

Tsarin idodin POSIX, da "alama" kamar yadda ya dace da XPG4 ta X/Open consortium) . 

Gine -ginen VAX da tsarin aiki na OpenVMS an “ƙera su lokaci guda” don cin moriyar juna, kamar yadda aka fara aiwatar da ginin VAXcluster . Sauran tsarin aiki na VAX sun haɗa da sakewa daban -daban na BSD UNIX har zuwa 4.3BSD, Ultrix -32, VAXELN, da Xinu . Kwanan nan, NetBSD  da OpenBSD  sun goyi bayan nau'ikan VAX daban -daban kuma an yi wani aiki akan jigilar Linux zuwa ginin VAX.  OpenBSD ta katse tallafi don gine -gine a watan Satumba na  shekara ta 2016.

## Tarihi

Samfurin VAX na farko da aka sayar shi ne VAX-11/780, wanda aka gabatar a ranar 25 ga  watan Oktoba,acikin shekara ta  1977, a Taron shekara-shekara na masu hannun jari.  Bill Strecker, C. Gordon Bell dalibin digiri na uku a Jami'ar Carnegie Mellon, shine ke da alhakin gine -gine.  Yawancin samfura daban -daban tare da farashi daban -daban, matakan aiwatarwa, da iyawa daga baya an ƙirƙira su. VAX superminicomputers sun shahara sosai a farkon shekara ta 1980.

Domin a yayin da VAX-11/780 da aka yi amfani da matsayin misali a CPU asowar . An bayyana shi da farko a matsayin injin MIPS ɗaya, saboda aikin sa yayi daidai da Tsarin IBM/360 wanda ke gudana a MIPS ɗaya, kuma aiwatar da Tsarin/360 a baya sun kasance ƙa'idodi na zahiri. Ainihin adadin umarnin da aka aiwatar a cikin daƙiƙa 1 ya kusan 500,000, wanda ya haifar da gunaguni na wuce gona da iri na talla. Sakamakon shine ma'anar "VAX MIPS," gudun VAX-11/780; kwamfutar da ke aiki a 27 VAX MIPS zata gudanar da wannan shirin kusan sau 27 da sauri fiye da VAX-11/780.

A cikin al'ummomin Dijital kalmar *VUP* ( VAX Unit of Performance ) ita ce mafi yawan lokuta, saboda MIPS ba sa kwatanta kwatankwacin gine -gine daban -daban. An yi *amfani da VUPs gungu mai* alaƙa ba tare da izini ba don bayyana jimlar aikin VAXcluster . (Ayyukan VAX-11/780 har yanzu suna aiki azaman ma'aunin ma'auni a cikin BRL-CAD Benchmark, ɗakin nazarin ayyukan da aka haɗa a cikin rarraba software na ƙirar ƙirar ƙirar BRL-CAD. ) VAX-11/780 ya haɗa da madaidaiciyar madaidaiciyar LSI-11 kwamfutar da ta yi nauyin microcode, booting, da ayyukan bincike don kwamfutar mahaifa. An sauke wannan daga samfuran VAX masu zuwa. Sabbin masu amfani da VAX-11/780 saboda haka zasu iya gudanar da tsarin aiki daban-daban na Kamfanin Kayan Kayan Dijital guda uku: VMS akan injin VAX (daga rumbun kwamfutoci), kuma ko dai RSX-11S ko RT-11 akan LSI-11 (daga guda ɗaya kawai drive floppy disk).

VAX ta shiga aiwatar da ayyuka daban -daban. An aiwatar da VAX 11/780 na asali a cikin TTL kuma ya cika kabad mai ƙafa huɗu da biyar  tare da CPU ɗaya. Ayyukan CPU waɗanda suka ƙunshi madaidaicin ƙofar ECL da yawa ko kwakwalwan tsararren macrocell sun haɗa da VAX 8600 da 8800 superminis kuma a ƙarshe injunan babban aji na VAX 9000. Ayyukan CPU waɗanda suka ƙunshi kwakwalwan al'ada na MOSFET da yawa sun haɗa da injinan aji 8100 da 8200. An gina VAX 11-730 da 725 ƙananan injuna ta amfani da abubuwan haɗin AMD Am2901 bit-slice don ALU.

MicroVAX I na wakiltar babban canji a cikin dangin VAX. A lokacin ƙirarsa, har yanzu bai yiwu a aiwatar da cikakken ginin VAX azaman guntu ɗaya na VLSI ba (ko ma chipsan kwakwalwan VLSI kamar yadda aka yi daga baya tare da V-11 CPU na VAX 8200/8300). Madadin haka, MicroVAX I shine farkon aiwatar da VAX don motsa wasu daga cikin mahimman umarnin VAX masu rikitarwa (kamar ƙuntataccen adadi da lambobi masu alaƙa) zuwa software na kwaikwayo. Wannan rabe -raben ya rage adadin microcode da ake buƙata kuma an kira shi da gine -ginen "MicroVAX". A cikin MicroVAX I, ALU da rijista an aiwatar dasu azaman guntu-madaidaicin guntu yayin da sauran sarrafa na'ura shine dabaru na al'ada.

Cikakken VLSI ( microprocessor ) aiwatar da ginin MicroVAX ya isa tare da MicroVAX II's 78032 (ko DC333) CPU da 78132 (DC335) FPU. A 78032 shi ne na farko microprocessor da wani a kan-jirgin memory management naúrar  A MicroVAX II ya ginu ne kan guda, hudu-sized processor jirgin wanda ya kwashe processor kwakwalwan kwamfuta da gudu cikin MicroVMS ko Ultrix -32 tsarukan . Na'urar ta ƙunshi 1 MB na ƙwaƙwalwar ajiya a kan jirgi da keɓaɓɓiyar tashar motar Q22 tare da canja wurin DMA. MicroVAX II ya ci nasara ta wasu samfuran MicroVAX da yawa tare da ingantaccen aiki da ƙwaƙwalwar ajiya.

Ƙarin masu sarrafa VLSI VAX sun bi ta hanyar V-11, CVAX, CVAX SOC ("System On Chip", CVAX guda ɗaya), Rigel, Mariah da aiwatar da NVAX. Na'urorin microprocessors na VAX sun haɓaka gine-ginen zuwa wuraren aiki masu arha kuma daga baya kuma sun maye gurbin manyan samfuran VAX. Wannan fannonin dandamali masu yawa (babba zuwa babban aiki) ta amfani da gine -gine guda ɗaya ya bambanta a masana'antar kwamfuta a wancan lokacin. An zana zane -zanen Sundry akan injin microprocessor na CVAX. Maganar *CVAX ... lokacin da kuka damu sosai don yin sata mafi kyawun* an rubuta shi a cikin Rashanci mai fashewa azaman wasa akan taken Hallmark Cards, wanda aka yi niyya a matsayin saƙo ga injiniyoyin Soviet waɗanda aka san su duka suna lalata komputa na DEC don aikace -aikacen soji da juyawa. aikin injiniyan su.  

A cikin abubuwan samarwa na DEC, fasahar RISC ta maye gurbin gine -ginen VAX. A cikin shekara ta 1989 DEC ta gabatar da kewayon wuraren aiki da sabar da ke gudana Ultrix, DECstation da DECsystem bi da bi, dangane da masu sarrafawa waɗanda suka aiwatar da ginin MIPS . A cikin  shekara ta 1992 DEC sun gabatar da nasu tsarin koyar da tsarin RISC, Alpha AXP (daga baya aka sake masa suna Alpha), da nasu microprocessor na tushen Alpha, DECchip 21064, babban ƙirar 64-bit mai iya gudanar da OpenVMS.

A watan ogusta a  cikin shekara ta  2000, Compaq ya ba da sanarwar cewa za a daina sauran samfuran VAX a ƙarshen shekara.  Zuwa shekarar 2005 duk kera kwamfutocin VAX sun daina aiki, amma tsofaffin tsarin suna ci gaba da amfani. 

A Stromasys CHARON-VAX da SIMH software-tushen VAX emulators zama samuwa da kuma VMS yanzu gudanar da VMS Software Incorporated, ko da yake sun kawai bayar da OpenVMS for Alpha tsarin da HPE Mutunci Servers, tare da x86-64 goyon bayan da ake ci gaba, da kuma ba bayar da shi don VAX.

## Tsarin gine -gine

### Taswirar ƙwaƙwalwar ajiya
VAX memory memory ya kasu kashi hudu. Kowane yana da gigabyte ɗaya (a cikin mahallin magana, 2 30 bytes) a girman:

Don VMS, an yi amfani da P0 don sararin sarrafa mai amfani, P1 don tari tsari, S0 don tsarin aiki, kuma an adana S1.

### Yanayin gata
VAX tana da hanyoyin gata guda huɗu waɗanda aka aiwatar:

### Rijistar matsayin mai aiwatarwa
Rijistar Matsayin Tsarin yana da ragowa 32:

## Tsarin tushen VAX
Tsarin farko na tushen VAX shine VAX-11/780, memba na dangin VAX-11 . Babban VAX 8600 ya maye gurbin VAX-11/780 a cikin Oktoba shekara ta 1984 kuma ya haɗa shi da matakan shigarwa na ƙananan microVAX masu amfani da ƙananan tashoshin VAXstation a tsakiyar 1980s. VAX 4000 ya maye gurbin MicroVAX, VAX 8000 ya maye gurbin VAX 6000 a ƙarshen shekara ta 1980s kuma an gabatar da babban matakin VAX 9000 . A farkon shekarun da 1990, an gabatar da VAXft mai haƙuri da laifi, kamar yadda Alpha ya dace VAX 7000/10000 . An sayar da nau'ikan nau'ikan tushen tushen VAX azaman VAXserver.

### SIMACS (ACceSs na Injin Sau ɗaya)
*Masana'antu na System sun* haɓaka iyawa don samun fiye da ɗaya DEC CPU, amma ba a lokaci guda ba, suna da damar yin rubutu zuwa faifai da aka raba. Sun aiwatar da haɓakawa da ake kira SIMACS (SIm Sameous Machine ACceSs),   wanda ya ba da damar mai sarrafa faifan su na musamman ya saita tutar semaphore don samun damar faifai, yana ba da damar RUBUTU da yawa zuwa fayiloli guda; an raba faifan ta tsarin DEC da yawa. *Hakanan SIMACS* ya kasance akan tsarin PDP-11 RSTS .

### Tsarin da aka soke
Soke tsarin hada da *"BVAX",* a high-karshen ECL tushen VAX, da kuma biyu sauran ECL-tushen VAX model: *"Argonaut"* da *"Raven".*  An soke Raven a shekara ta  1990.  An kuma soke wata VAX da aka sani da suna " *Gemini* ", wacce ta kasance koma baya idan har *Scorpio na* tushen LSI ya gaza. Bai taba jigilar ba.

### Clones
An samar da adadin clones na VAX, duka masu izini da mara izini. Misalai sun haɗa da:

* Kamfanin Systime Computers Ltd na Burtaniya ya samar da clones na samfuran VAX na farko kamar Systime 8750 (kwatankwacin VAX 11/750). 
* Norden Systems ya samar da rudani, ƙayyadaddun tsarin sojan MIL VAX. 
* A Hungarian Tsakiya Research Institute for Physics (KFKI) samar da wani jerin kwafi masu kunnen doki na farkon VAX model, da TPA-11/540, 560 da kuma 580. 
* SM 52/12  daga Czechoslovakia, wanda aka haɓaka a VUVT Žilina (yau Slovakia ) kuma aka samar daga shekara ta  1986 a ZVT Banská Bystrica (yau Slovakia ).
* Gabashin Jamus VEB Robotron Knbsp;1840 (SM 1710) clone ne na VAX-11/780 kuma Robotron K 1820 (SM 1720) kwafin MicroVAX II ne.
* *SM-1700* shine clone na Soviet na VAX-11/730, *SM-1702 ya* kasance mai ɗaukar hoto na MicroVAX II kuma *SM-1705* ya kasance clone na VAX-11/785. 
* NCI-2780 Super-mini, wanda kuma aka sayar da shi azaman Taiji-2780, shine clone na VAX-11/780 da Cibiyar Fasahar Kwamfuta ta Arewacin China ta samar a Beijing.  

## Kara karantawa
*

## Manazarta

## Hanyoyin waje

* HP: Tsarin VAX 
* DEC Microprocessors
* SimH VAX Open emulator wanda ke goyan bayan gine -ginen VAX
* Cikakken Jaridun Fasaha na Dijital