Page 27 - FUNDAMENTALS OF COMPUTER

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NPP Computer Basics and Windows Fundamentals 27

sign, parity, overflow condition etc. 8085 has 8- ~VmVr h¢ Ÿ& CXm. Ho$ {bE, âboJ {~Q²>g H¡$ar, gmBZ no[aQ>r,
bit flag register and 8086 has 16-bit flag register. Amodaâbmo H$ÊS>reZ Am{X Xem©Vr h¡& 8085 CPU _| 8-
{~Q>m| H$m âboJ a{OñQ>a h¡ O~{H$ 8086 _| 16 {~Q>m| H$m&
(h) Stack Pointer (SP) (h) ñQ>oH$ nm°BªQ>a
SP is a special purpose CPU register which SP EH$ {deof H$m`© a{OñQ>a h¡ Omo {H$ ñQ>oH$ Ho$ Q>m°n
points to the top of the stack. The stack is a H$mo ~VmVm h¡Ÿ& ñQ>oH$ AñWm¶r S>mQ>m Ho$ g§J«hrV H$aZo Ho$
portion of read write memory to store tempo-
rary data. There are two operations which can {bE arS> amBQ> ‘o‘moar H$m hr EH$ {hñgm h¡Ÿ& Bg_| nwe VWm
be performed on the stack; push and pop. When nm°n Xmo {H«$`mE± H$a gH$Vo h¡Ÿ& AV… nwe `m nm°n H$aZo na
push operation is performed the data is in- ñQ>oH$ H$s pñW{V VWm Q>m°n _| n[adV©Z AmEJmŸ& AV … SP
serted onto the stack and when pop operation
is performed the data is retrieved from the stack. ñdV… H$_ `m A{YH$ hmoH$a h_oem ñQ>oH$ Ho$ Q>m°n ES´>og H$mo
The top of the stack and therefore the contents ~VmVm h¡Ÿ& nwe H$aZo go S>mQ>m ñQ>oH$ _| OmVm h¡ VWm nm°n go
of stack pointer are modified after every push
and pop operation. ~mha AmVm h¡Ÿ&
1.2 Computer Generations 1.2 H$åß`yQ>a nr{‹T>`m±
Electronic Computers are those in which {OZ H$åß`yQ>am| _| BboŠQ´>m°Zm| H$s J{V H$m Cn`moJ
movement of electron is used for the flow of H$aHo$ OmZH$mar H$mo EH$ ñWmZ go Xygao ñWmZ na ^oOm
information. Vacuum Tube (Electric valve), OmVm h¡, BboŠQ´>m°{ZH$ H$åß`yQ>a H$hbmVo h¢Ÿ& {Zdm©V Q²>`y~,
semiconductor components or integrated cir-
cuits are used to make these computers. They AY©MmbH$ Ad`d `m B§Q>rJ«oQ>oS> n[anW H$m Cn`moJ H$aHo$
permit processing and storage of digital sig- BÝh| ~Zm`m OmVm h¡Ÿ& BZgoo OmZH$mar EH$ ñWmZ go Xygao
nals at a very high speed. The evolution of ñWmZ na CÀM J{V go OmVr h¡Ÿ& gmW hr CÀM J{V go
electronic Computers can be classified with the {H«$`mE± ^r hmoVr h¡Ÿ& BZH$mo {dH$mg Ho$ AmYma na {ZåZ
help of following generations : nr‹T>r`m| _| dJuH¥$V H$a gH$Vo h¢ …
1. First Generation (1946-1954) 1. àW_ nr‹T>r (1946 - 1954)
2. Second Generation (1954-1964) 2. {ÛVr` nr‹T>r (1954 - 1964)
3. Third Generation. (1965-1974) 3. V¥Vr` nr‹T>r (1965 - 1974)
4. Fourth Generation.(1975 to till date) 4. MVwW© nr‹T>r (1975 go A~ VH$)
5. Fifth Generation. (future) 5. n§M_ nr‹T>r (^{dî`)
First Generation (1946 - 1954) àW_ nr‹T>r (1946-1954)
The generation using vacuum tube com- {OZ H$åß`yQ>am| _| BboŠQ´>m°{ZH$ dmëd `m doŠ`y_
puters is usually referred to as first generation Zbr H$mo Ad`dm| Ho$ ê$n _| Cn`moJ {H$`m J`m Wm, CÝh|
computers. The first generation computers can àW_ nr‹T>r _| aIVo h¢ Ÿ& Bg nr‹T>r Ho$ H$åß`yQ>am| _| {ZåZ
be characterised by following features:
{deofVmE± Wr…
1. They used vacuum tubes (Electronic 1. CPU Ho$ Ad`dm| Ho$ ê$n _| {Zdm©V Zbr H$m Cn`moJ
valves) as CPU Components.
{H$`m J`m WmŸ&
2. They used fixed-point arithmetic. 2. `o pñWa-q~Xw A§H$J{UV H$m Cn`moJ H$aVo WoŸ&