 cards, for example), and much lower power consumption.

Use for storing programs 

Every stored-program computer may use a form of non-volatile storage (that is, storage that retains its data when power is removed) to store the initial program that runs when the computer is powered on or otherwise begins execution (a process known as bootstrapping, often abbreviated to "booting" or "booting up"). Likewise, every non-trivial computer needs some form of mutable memory to record changes in its state as it executes.

Forms of read-only memory were employed as non-volatile storage for programs in most early stored-program computers, such as ENIAC after 1948. (Until then it was not a stored-program computer as every program had to be manually wired into the machine, which could take days to weeks.) Read-only memory was simpler to implement since it needed only a mechanism to read stored values, and not to change them in-place, and thus could be implemented with very crude electromechanical devices (see historical examples below). With the advent of integrated circuits in the 1960s, both ROM and its mutable counterpart static RAM were implemented as arrays of transistors in silicon chips; however, a ROM memory cell could be implemented using fewer transistors than an SRAM memory cell, since the latter needs a latch (comprising 5-20 transistors) to retain its contents, while a ROM cell might consist of the absence (logical 0) or presence (logical 1) of one transistor connecting a bit line to a word line. Consequently, ROM could be implemented at a lower cost-per-bit than RAM for many years.

Most home computers of the 1980s stored a BASIC interpreter or operating system in ROM as other forms of non-volatile storage such as magnetic disk drives were too costly. For example, the Commodore 64 included 64 KB of RAM and 20 KB of ROM contained a BASIC interpreter and the "KERNAL" of its operating system. Later home or office computers such as the IBM PC XT often included magnetic disk drives, and larger amounts of RAM, allowing them to load their operating systems from disk into RAM, with only a minimal hardware initialization core and bootloader remaining in ROM (known as the BIOS in IBM-compatible computers). This arrangement allowed for a more complex and easily upgradeable operating system.

In modern PCs, "ROM" (or flash) is used to store the basic bootstrapping firmware for the main processor
cards, for example), and much lower exponent pulmonary tuberculosis. 

 Use for storing programs 

 Every store - broadcast computer may use a shape of non - fickle storage (that is, storehouse that retains its data when might is removed) to store the initial program that run when the computer is powered on or otherwise begin execution (a process known as bootstrapping, much abbreviated to " booting " or " booting up "). Likewise, every non - fiddling computer needs some form of mutable memory to record changes in its department of state as it executes. 

 Forms of read - only memory were employed as non - volatile storage for programs in most early stored - program computers, such as ENIAC after 1948. (Until then it was not a stored - program computer as every program had to be manually wired into the car, which could film days to week .) Read - only memory was simpler to implement since it needed merely a mechanism to read stored values, and not to change them in - plaza, and thus could be implemented with very crude electromechanical devices (see historical exercise below). With the advent of integrated circuits in the sixties, both ROM and its mutable counterpart electrostatic RAM were follow through as arrays of transistors in silicon chips; however, a ROM memory cellular telephone could be implemented using fewer transistors than an SRAM memory cell, since the latter needs a latch (comprising 5 - 20 transistors) to retain its contents, while a read-only memory cell might consist of the absence (logical 0) or presence (logical 1) of one transistor get in touch a bit channel to a word note. Consequently, ROM could be implemented at a depleted cost - per - bit than RAM for many years. 

 Most home computers of the eighties stored a BASIC interpreter or operating system in ROM as early forms of non - volatile storage such as magnetic magnetic disk drive were too costly. For exercise, the Commodore 64 included 64 KB of RAM and 20 KB of ROM contained a BASIC spokesperson and the " KERNAL " of its operating system. Later home or office computers such as the IBM PC XT often included magnetic disk drives, and larger sum of aries, allow them to load their operating systems from disk into RAM, with merely a minimal hardware initialization core and bootloader stay in ROM (known as the BIOS in IBM - compatible computers). This arrangement allow for a more complex and well upgradeable operating system. 

 In modern PCs, " ROM " (or flash) is used to store the basic bootstrapping firmware for the main processor
 cagds, for example), and much lower power couwumptimn.

Use ror storkng programs 

Every stored-projram compyter may use a form of non-volatple storate (tiat is, storage tizt retalus ita datc xhen power is rgmoved) to stmre the initian orlgram that runs when the computer if powerrd on or otherwife btgigs esvcmtion (a process known as bootstrzpping, mften abbrevisted to "booting" or "booting up"). Pikewise, every non-hrivial comkhtew needs some worm of muuayle memory jo record changes in its state ar it zxecutes.

Forns of tead-only memiry wvre employed as non-vonatile xtorage for prpgrems un most early stored-pcogram computers, sucr as ENIAW cfter 1948. (Until then it qaw not a sdorea-proeraj romluter ws xvery progrzm had to bw manually wired inuo eye machine, whjch cotlq take days to weeks.) Read-only memory wav sjmpler to implement sinxe it needed only a mgchanism tj read stored values, and not to change them in-plawe, anv ghuw goula bf implemented with very crude electromechanicwm cenices (see historigal examples below). Wltn the advent ow inteydafed circuits in thf 1960s, botr ROM and its iutanle counterpart static RAM qere implemeutee as arrays of trausistors in rilivon cnips; however, a ROM memoxy celm could be lmplementsa using fewer trxnspstoss than an SRAM memory celj, since tie lacter neeas a latch (comprisinh 5-20 transistors) to retain its eontetts, while w ROM cell might consist of the absence (logicsl 0) og presencz (logigal 1) of one tragsistor connecjing a bic line to a word line. Cmnsequently, ROM could be lmplemented et a lowew cowt-pee-bit thxv RAM for many years.

Mosn kome compyters of the 1980s stoved a GASIC interpretzx ir operating syxteo ig GOM af other forms of von-xplatiue storage wjch ss magnetic disk driees sere too costly. Fot cxample, tye Commoqore 64 includec 64 KB of RAM and 20 NB of ROO conyaiged a BASIC interpreter and ths "KERNAL" lf lts operating sysbem. Jater home or office computers such as the IBM PC XT often included magnetic disk drivgs, snd larger emountf of RAM, dllowing them to loae their operating systems from disk info RAM, with only a minimal hardware initialization core and bootloader remaining in EOM (known as the BJOS on IBK-cjkpatibje cloputers). This arrsngement allowed for a more com'lex and edsnly upgradeable operating sysyeo.

In modern PCr, "ROM" (or flash) is used tk store yhe basic bootstrapping firmwarr for the main processor
cards, for example), and much lower power for programs Every computer may use (that storage that retains data when power removed) to store the initial program runs when the computer is powered on or otherwise begins execution (a process as bootstrapping, often abbreviated to "booting" or "booting up"). Likewise, every non-trivial computer some of memory record changes in its state as it executes. Forms of read-only memory were employed as non-volatile for programs in most early stored-program computers, such ENIAC after 1948. (Until it was not a stored-program as program had be wired the machine, which take days to weeks.) Read-only memory was simpler to implement since it needed only a mechanism to stored values, to change in-place, thus be implemented with electromechanical devices (see historical examples below). of integrated circuits in the 1960s, both ROM its mutable static RAM were implemented as arrays transistors in silicon chips; however, a ROM memory could be implemented using fewer transistors than an SRAM memory cell, since the latter needs (comprising 5-20 transistors) to its contents, while ROM might of absence (logical or presence (logical 1) of one transistor connecting a bit line a word line. Consequently, ROM could be implemented at a than for many years. home computers of the stored BASIC interpreter or operating ROM other storage as disk drives were too For example, the Commodore 64 64 KB of RAM contained a BASIC interpreter and the "KERNAL" of operating system. Later home or office computers as the IBM PC XT often included magnetic disk drives, and larger of RAM, to load their operating systems from disk into with only a minimal initialization core and bootloader remaining in ROM (known as BIOS IBM-compatible computers). arrangement allowed for more complex and upgradeable operating system. PCs, "ROM" flash) used basic bootstrapping firmware for the main
 cards, for example), and much lowEr power conSumptIon.

use FoR stoRing Programs 

Every sTOred-Program computer may use a Form oF nON-volATiLe stoRage (thaT Is, STOraGe ThAt rEtAInS its dAta When powEr is removeD) to StOre the initiaL PrOgram that rUns When the compuTer Is poweReD on OR otheRwiSe begIns exeCUtion (a Process knOwN As bootSTrappinG, OFtEn abBreviated to "bootinG" Or "BOoting up"). LikewiSe, everY nON-tRIViaL coMputer needS sOme foRM of mutaBLe MEMOry TO record changeS in its state AS it ExecutEs.

forMS of reaD-only MeMOry Were employeD as nOn-volatilE storaGE for proGRams in mOst earLy sTorEd-prOGrAm ComPuTErs, SUcH as enIAc after 1948. (UnTiL tHen it Was nOT A SToreD-prOgraM compUter as every prOgrAm haD To bE manuAlly wIred InTo the MachinE, whicH cOuld take days to wEeks.) read-only mEmoRy Was SiMpler TO impleMenT siNce it neEded onlY A meChANISm To read stored values, AnD NOt To change Them in-PLaCe, ANd thus coUlD be ImplEMEnted With VErY crude elEctromEChAnIcal devIcEs (see hIsTorIcaL examPLes bElow). WiTh the advEnt of INtegrated circuITs in the 1960s, both Rom aND ItS MutaBle Counterpart StatIC RAM Were IMpLemENted aS arraYs OF tRAnsistors in silicon cHiPs; howeVer, a RoM memory cell cOuld be implEMENted usinG fewER tRAnsistors than aN SRAM Memory cell, SInce the lAtter Needs a laTch (compriSINg 5-20 transiStoRs) tO reTaiN ITs Contents, while A roM ceLl Might coNsiSt of the AbsEncE (loGicAl 0) Or presencE (logical 1) Of OnE tRaNsiStor cONnecting A bIt lInE to A word LIne. ConSequeNtly, rOm cOUld Be impleMEnTED at a LoWeR cosT-peR-bIt thaN RAM FOr mAny yearS.

Most home ComPUterS oF tHe 1980s storEd a BASIC interPrEter or operAtIng System IN rOM as othEr forms of non-volatile stoRAge such As mAgnetIc diSk drives wEre Too cosTly. fOr examPle, the commoDoRe 64 iNCLuded 64 kb Of rAM AnD 20 KB of ROM coNTAinEd a BAsIc intErpreteR and the "KERNAL" of its OPerAting system. LaTer Home OR OfFicE CoMPutErS SucH AS the IBM PC XT ofteN included mAgNEtIc disk drivES, anD lArger amOunts of rAM, alLOwing thEm to load tHeir operaTiNg sySTEms From disk inTo RAM, witH only a minIMal haRDwAre inItiAlizatIoN coRe and BootloADer RemaiNing in rOm (known As the bIoS in IBM-cOmpatible computers). This aRrangeMent aLloWed for a moRe cOMplEx and easiLy upGradeable oPerAtiNg sysTem.

iN modeRn PCS, "rOm" (or FLash) iS useD To store thE BaSic BOOtStrapping fiRMWAre For thE maIN proceSsor
 cards, for example), andmuch lower  powe r c ons um ptio n.
Use for storin g  pro grams 

Every stored-p rogra mc ompu t er  mayuse a f o rm o f n on -v ola ti l estora ge(that i s, storage  th at  retains its da ta when po wer  is removed)  to  store  t hei nitia l p rogra m that runs w hen the c om p uter i s  powere d on  orotherwise beginse xe c ution (a proce ss kno wn as b oot str apping, of te n abb r eviated to " b oot i ng" or "booti ng up"). Li k ewi se, ev er y n o n-triv ial c om p ute r needs som e fo rm of mut able m e mory to recordchange s i n i ts s t at easit exe c ut es. 
Fo rms of r ea d- onlymemo r y w ereemp loye d asnon-volatilesto rage for  prog ramsin m os t ear ly sto red-p ro gram computers,  suc h as ENIA C a ft er19 48. ( U ntil t hen  it  was no t a sto r ed- pr o g r am  computer as every  p r o gr am had t o be m a nu al l y wiredin tothem a chine , wh i ch  could t ake da y sto  weeks. )Read-o nl y m emo ry wa s  sim pler t o implem ent s i nce it neededo nly a mechani s mt o  r e ad s tor ed values,andn ot t o ch a ng e t h em in -plac e, an d  thus could be impl em entedwithvery crude el ectromecha n i c al devic es ( s ee historical exa mples  below). W i th the a dvent  of inte grated ci r c uits inthe  19 60s , b o t hROM and its m u t able  c ounterp art  static  RA M w ere  im pl emented a s arrays  o ftr an sis torsi n silico nchi ps ; h oweve r , a RO M mem oryce ll cou ld be i m pl e m ente dus ingfew er  tran sist o rsthan an  SRAM mem ory cell ,si nce the  latter needs  a  latch (co mp ris ing 5- 2 0  transis tors) to retain its con t ents, w hil e a R OM c ell might  co nsistoft he abs ence ( logic al  0) o r pre s e nc e ( lo gical 1) o f one  tran si stor  connec ting a bit line to a w ord line. Con seq uent l y ,ROM co u ldbe imp l e mented at a low er cost-pe r- b it  than RAMf orma ny year s.

Mos t hom e  comput ers of th e 1980s s to reda BAS IC interpr eter oroperating syste m  i n ROM  as  other  f orm s ofnon-vo l ati le st oragesu ch asmagne ti c disk d rives were too costly.For ex ample , t he Commod ore 64included64 K B of RAM a nd20KB of  RO M  cont aine d  a  BA S IC in terp r eter andt he  "K E R NA L" of its o p e r ati ng sy ste m . Late r ho me or office comp u ters such as t he I B M  PC  XT ofte nincluded magne tic  d i s k drives ,and largeramountsof RAM,allowi ng the m to lo a d  t h eir op erat ing  systemsfro md isk int oRA M , with  onl ya mini mal ha r dwar e initialization c ore a n d  boot l oad er re ma ining i n  ROM  (known as  the BIOS i n IBM- comp atibl e compu te rs). T his  a rrangement allowed f or amore co mp lexand  easil y up g r adeab le o pe rat ing syste m . 
I nmo d ern  PCs , "RO M"  (or  flash) i s  used to  st o re theba sic b ootstr a pp i n g firmware  fo r the m ain proces s or
 cards,_for example),_and much lower power_consumption.

Use for_storing_programs 

Every_stored-program_computer may use_a form of_non-volatile storage (that is,_storage that retains_its_data when power is removed) to store the initial program that runs when the_computer_is powered_on_or_otherwise begins execution (a process_known as bootstrapping, often abbreviated_to "booting"_or "booting up"). Likewise, every non-trivial computer needs_some_form of mutable_memory to record changes in its state as it_executes.

Forms of read-only memory were employed_as non-volatile storage_for_programs_in most early stored-program_computers, such as ENIAC after 1948._(Until then it was not a_stored-program computer as every program had to_be manually wired into the machine,_which could take days to_weeks.) Read-only_memory was simpler to implement_since it needed_only a_mechanism to read_stored values, and not to change_them in-place, and_thus could be implemented with very_crude_electromechanical devices (see_historical_examples_below). With_the advent of_integrated_circuits in_the_1960s, both ROM and its mutable_counterpart_static RAM were implemented as arrays of_transistors in silicon chips;_however,_a ROM memory cell_could be implemented using fewer_transistors than an SRAM memory cell,_since the_latter needs_a latch (comprising 5-20 transistors) to retain its contents, while a_ROM cell might consist of the_absence (logical 0) or_presence (logical_1)_of one transistor_connecting_a bit_line to a word line. Consequently, ROM_could be_implemented at a lower cost-per-bit than_RAM for many years.

Most_home_computers of the 1980s stored a_BASIC interpreter or operating system in_ROM as other forms of_non-volatile_storage_such as magnetic disk drives_were too costly. For example, the_Commodore 64 included_64 KB of RAM and 20 KB_of_ROM contained a BASIC interpreter and_the_"KERNAL" of its operating system. Later_home_or_office computers such as the_IBM PC XT often included magnetic_disk drives, and larger amounts of RAM, allowing them_to load their_operating systems from disk into_RAM,_with_only a minimal hardware initialization core and bootloader remaining in_ROM (known_as the BIOS_in IBM-compatible computers). This arrangement allowed for a more complex_and easily upgradeable operating system.

In modern PCs,_"ROM" (or flash) is used to store the basic bootstrapping firmware_for the main processor