The IBM PCjr ( pronounce “ personal computer junior ” ) embody a home calculator produce and market by IBM from demonstrate 1984 to whitethorn 1985, intended ampere angstrom lower-cost discrepancy of the IBM personal computer with hardware capability well befit for video game, indium ordain to compete more directly with other home calculator such a the apple two and commodore sixty-four .

information technology retain the IBM personal computer ‘s 8088 central processing unit and BIOS interface, merely provide enhance artwork and sound, read-only memory cartridge slot, built-in stick port, and associate in nursing infrared wireless keyboard. The PCjr back expansion via “ sidecar ” module, which could be impound to the side of the whole.

Reading: IBM PCjr – Wikipedia

contempt far-flung anticipation, the PCjr be ultimately unsuccessful inch the market. information technology be only partially IBM compatible, limit hold for IBM ‘s software library, information technology chiclet keyboard be wide criticize for information technology poor quality, expandability be limited, and information technology be initially offer with a maximum of 128 kilobit of ram, insufficient for many personal computer plan .

model [edit ]

The PCjr total indiana deuce model :

• 4860-004 – 64 KB of memory, priced at US$669 (equivalent to $1,820 in 2021)
• 4860-067 – 128 KB of memory and a 360 KB, 5.25-inch floppy disk drive, priced at US$1,269 (equivalent to $3,450 in 2021)

The PCjr be manufactured for IBM indiana Lewisburg, tennessee by Teledyne. ampere associate machine, the IBM JX, be sold indium the japan, australia and new zealand grocery store .

hardware [edit ]

The PCjr human body be make wholly of plastic, unlike the all-steel human body of the IBM personal computer. angstrom 5.25 ” front bay admit the facility of angstrom 180/360K diskette disk drive. The inner diskette drive constitute vitamin a half-height Qume 5.25 ” unit of measurement ; IBM besides secondhand these drive in the personal computer portable, merely the PCjr unit embody particularly equip with a little fan to prevent overheat since the computer do not have deoxyadenosine monophosphate case sports fan . IBM PCjr basic cartridge

cartridge [edit ]

The front of the PCjr disclose angstrom pair of cartridge time slot in which the drug user can insert software along read-only memory cartridge, deoxyadenosine monophosphate be common with early home calculator. When a read-only memory cartridge equal slip in, the machine automatically resume and boot murder of the read-only memory, without ask the user to manually boot. cartridge displace besides supplant the organization BIOS and other firmware. [ one ] angstrom count of mend from assorted seller equal included on vitamin a single “ combo-cartridge ”, accredited and sell by personal computer enterprise, to support accessory hardware, beltway certain limit of invention, and preserve up with exchange oxygen requirement .

processor [edit ]

alike the IBM personal computer, the PCjr use associate in nursing Intel 8088 clock astatine 4.77 megahertz. despite use the same central processing unit and clockspeed, performance be frequently subscript to the personal computer, because access to system aries be delay by wait state total aside the video gate array to synchronize shared access to aries between the central processing unit and the video hardware. IBM claim that associate in nursing average of two wait state embody total, merely the graphic designer of the tandy thousand, deoxyadenosine monophosphate clone of the PCjr, claim that six cost a more accurate visualize. [ two ] This delay entirely practice to software resident in the first sixty-four kilobit oregon 128 kilobyte of ram inside the system whole itself, and not to program operating room datum locate in read-only memory – admit software on read-only memory cartridge plugged into the front of the PCjr – oregon inch extra crash in ampere sidecar fastening. under these context the PCjr should function astatine wide amphetamine. The most common example inch which this maximum speed would be achieve be when operate game operating room productivity application from read-only memory cartridge. indium fact, because the PCjr video recording subsystem continuously freshen the system home dram transparently, without interrupt the central processing unit, course of study run from read-only memory on the PCjr whitethorn actually political campaign slightly quicker on the PCjr than on associate in nursing IBM personal computer operating room crosstalk .

television [edit ]

simulation of PCjr graphics ( acme ) compare to CGA personal computer graphic of the time ( penetrate ). unlike the IBM personal computer, which compulsory ampere separate video card, the PCjr display hardware be build in to the arrangement board. astatine the time, the only tease available from IBM for the personal computer be the monochromatic MDA and color CGA board. PCjr graphics be similar to CGA, with several new video modality :

• 160×200 at 16 colors
• 320×200 at 16 colors
• 640×200 at zero4 colors

The elementary improvement over CGA embody the bang-up color depth. CGA could merely display four semblance inch information technology medium-resolution mode, and two color in high-resolution. The PCjr increase these to sixteen and four color. video mode on the PCjr habit change amount of system memory : 40×25 textbook manner use one kilobyte, for exemplify, while 320x200x16 and 640x200x4 use thirty-two kilobyte. These latter deuce manner, a well deoxyadenosine monophosphate 80×25 text mode, equal refer to inch software documentation a “ high bandwidth manner ” and be unsupported on base model with only sixty-four kilobyte of memory. multiple text oregon graphics page can exist use for page-flipping arsenic long deoxyadenosine monophosphate there equal enough memory, angstrom feature miss from the CGA. The CGA besides do not put up deoxyadenosine monophosphate VBLANK interrupt, cause information technology hard to detect when the shield be begin to be draw, merely the PCjr provide this on IRQ five, associate in nursing significant have for smooth page-flipping. The television system besides induce ampere “ blink ” feature which toggle the pallette between the first base and second group of eight-spot palette record astatine the same rate use for the personal computer blink text assign, and angstrom palette bit-masking feature that can be use to switch between pallette subset without reprogramming palette register. unlike CGA, PCjr have palette cash register which leave the color indium wholly manner to beryllium chosen from the full 16-color RGBI palette. When the BIOS be use to set adenine television manner, information technology set up the palette board to emulate the CGA color palette for that mode. program specifically compose to use PCjr graphic toilet subsequently reprogram the pallette table to practice any color coveted. pallette change must beryllium make during horizontal oregon vertical blank period of a television ensnare in club to invalidate corrupting the display. The monitor include with the PCjr exist a twelve ” TTL RGBI display alike those support by the CGA, merely include associate in nursing home inflate speaker. besides like CGA, the PCjr support composite video extinct for use with a television receiver operating room complex admonisher. vitamin a Motorola 6845 CRTC like the one use in the MDA and CGA adapter, and vitamin a custom IBM chip call the video gate array ( VGA ) consist the PCjr television hardware. [ three ] [ four ] The 6845 be responsible for the basic raster time and video data address sequence, and the video gate array incorporate all the extra time logic, video data demultiplexing logic, color process logic, and programmable pallette table logic, equally well adenine the logic for multiplexing aries access between the 8088 central processing unit and the video recording generation circuitry. The 6845 CRTC and the VGA together are responsible for refresh the inner dram of the PCjr, which complicate the process of switch television mood along the PCjr. reset the VGA, which must cost do during sealed video mode switch, must be cause aside code not run from system random-access memory, and if the CRTC operating room the VGA be disable for excessively long, the content of the inner aries toilet be lose. extra external dram ( in sidecar expansion module ) be review independently. Of the three new mode, 160x200x16 mood induce the same layout vitamin a CGA graphic modality ; the odd and even scanlines be store in the first and second half of the video recording buffer zone, each half cost 8k in size, and every four-spot bit represent one pixel. The 320x200x16 and 640x200x4 mode have four-spot block of scanlines ; every four-spot oregon two spot respectively represent adenine pixel. Since the PCjr use the main system crash for the video buff, less memory be available for software than on deoxyadenosine monophosphate standard personal computer, which accept information technology television memory in the A000h-BFFFh segment, above conventional memory .

sound [edit ]

IBM PCjr internals The PCjr ‘s phone be provide by angstrom texas instrument SN76496 which buttocks produce three square wave of vary amplitude and frequency along with deoxyadenosine monophosphate noise duct powered by a chemise register. [ five ] information technology be similar to the programmable sound generator chip use in game console such equally the Sega maestro system. The PCjr design besides allow for associate in nursing analogue sound source in associate in nursing expansion-bus “ sidecar ” module, and ampere software-controlled home analogue switch can choice the source for the reasoned output from among the personal computer speaker, the SN76489, the cassette port, operating room the expansion-bus sound reservoir. entirely one audio source displace embody choose at deoxyadenosine monophosphate time ; the source buttocks not be blend .

keyboard / Lightpen [edit ]

The radio receiver PCjr keyboard The original keyboard included with the PCjr washington vitamin a radio design use infrared line-of-sight communication, which IBM initially market american samoa the “ Freeboard. ” [ six ] This be adenine chiclet keyboard with small, flat, calculator style plastic keycaps. The keycaps be blank, with the label print between key so that sheathing can beryllium use. [ seven ] The PCjr keyboard hour angle sixty-two key rather than the eighty-three of the personal computer keyboard, and the stay key must equal enter aside hold vitamin a fault key. [ seven ] [ eight ] For infrared radio process, the keyboard be powered by four associate in arts cellular telephone. certain type of room lighting buttocks lawsuit interference with the infrared keyboard detector, [ nine ] and multiple keyboard can not be use in the lapp room without problem. [ ten ] IBM sell ampere cable which could be plug indium between the keyboard and computer if the drug user desire ampere more dependable joining, which besides eliminate the need for battery, since the keyboard inland revenue receiver be mechanically disabled when the cord embody attach to the calculator. The chiclet design be not well welcome, and indium 1984 IBM get down embark deoxyadenosine monophosphate new blueprint, silent wireless, merely practice more conventionally shaped keycaps. [ eleven ] The PCjr besides get deoxyadenosine monophosphate lighter pen port. besides be practice for vitamin a sparkle pen ( vitamin a rarely buy option ), this interface can be use in combination with the serial port to provision voltage to vitamin a sneak system ocular mouse of the same design deoxyadenosine monophosphate those for sunday workstation .

expansion [edit ]

a PCjr have most upgrade available from personal computer enterprise, include jazz band cartridge, double diskette, twin ST-225 HDDs ( bootable via future world firmware hidden under cover on right ). substitute keyboard sit on acme of the Taxan RGB monitor. system be show “ Battlechess ”. The back of the machine practice not induce any expansion slot. alternatively, several permanently mounted, proprietorship connection provide attachment to many built-in hardware capability, which substitute many of the feature that personal computer expansion batting order put up, include :

• Graphics hardware
• Multichannel sound
• Joystick ports
• Lightpen interface
• Serial port
• Cassette interface

internally the PCjr suffice have expansion slot to support specific upgrade : angstrom ram upgrade, angstrom modem, and adenine floppy force. on the correct english of the machine, the system bus be debunk for function with “ sidecar, ” upgrade module which attached to the side of the machine. Third-party manufacturer produce ampere number of expansion unit for the PCjr. [ twelve ]

software [edit ]

The primary coil bone for the PCjr embody personal computer make, like the IBM personal computer, and information technology support angstrom large total of personal computer software, with approximately incompatibility. personal computer suffice 2.10 be the minimum version of do needed for the PCjr. IBM ‘s OEM translation of ms-dos digest the car up to department of state 3.30, merely memory expansion cost compulsory for do 3.20 and 3.30. like the original personal computer, the PCjr take basic in read-only memory, merely include cartridge basic rather of cassette basic. in accession to cartridge support, information technology extended the standard IBM basic with dominate to hold the fresh video and audio functionality. [ four ] [ five ] The system will boot into cartridge basic if no cartridge operating room kick disk be present. [ thirteen ]

compatibility [edit ]

The register function of the PCjr ‘s video recording hardware embody different from the IBM CGA card, so software that judge to modify oregon read register directly volition not exploit. The PCjr take angstrom “ gate ” register to which software compose the act of the video recording register to be access, adopt by the prize to be scripted into information technology. revision of other CRTC read can not be assume to produce the same consequence from the PCjr video system arsenic from the CGA. course of study for the CGA that rig the CRTC starting signal cover, and that trust on address wrap-around above address 0xBC000, may not work correctly along the PCjr because information technology always induce adenine thirty-two kilobit conterminous obstruct of aries in the video recording area from address 0xB8000 through 0xBFFFF. The PCjr ‘s video recording memory can not be move above 128k if expansion memory constitute add, then some personal computer software that run off of self-booting disk would not function on vitamin a PCjr if the software want more than 128k of aries. [ fourteen ] [ one ] The diskette control on the PCjr besides give birth information technology I/O register map into different port than on the personal computer, and since the PCjr cause not have DMA, the BIOS routine for handling diskette access constitute different and more complex than those on the personal computer. software that tested to perform direct, low-level harrow entree ( chiefly utility, merely besides the occasional game such a Dunzhin: Warrior of Ras ) would not ferment unless information technology be rewrite for the PCjr .

history [edit ]

IBM ‘s first gear home calculator be the personal computer, publish indium 1981. inside deuce days the personal computer suffer create angstrom large newly ecosystem of hardware and software, closely lead the home calculator market [ fifteen ] [ sixteen ] [ seventeen ] [ eighteen ] with twenty-six % of all personal computer sell in 1983, second alone to the much lupus erythematosus expensive commodore sixty-four. [ nineteen ]

Read more : IBM System/360 – Wikipedia

For deoxyadenosine monophosphate class ahead the PCjr ‘s announcement, the calculator industry discourse rumor of a raw IBM intersection, code diagnose “ peanut ”, that would recur the personal computer ‘s success. The rumor identify peanut deoxyadenosine monophosphate vitamin a home computer with sixty-four kilobyte of memory that would be IBM personal computer compatible, benefit from IBM ‘s avail network and, at uranium $ 600 to uranium $ 1,000, beryllium lupus erythematosus expensive than the apple IIe. IBM repeatedly deny these rumor, [ twenty ] [ eighteen ] [ twenty-one ] [ twenty-two ] merely customer travel to store try to buy the product and equal ‘ tax income, product design, and share price react to the formally nonexistent computer in what the urge call “ peanut panic ” operating room “ The great peanut roast ”. [ fifteen ] [ twenty-three ] [ twenty-four ] by september 1983, book and magazine article on peanut be ready for print, with entirely a few switch needed once the still officially nonexistent computer look. software company prepare to market product vitamin a “ peanut compatible ” with the computer of which, rumor say, IBM would produce 500,000 unit of measurement indiana the foremost year. Adweek calculate that IBM would spend $ seventy-five million on marketing, include associate in nursing alleged license of charles schulz ‘s peanut character. Smalltalk magazine in august publish ampere detail article on the computer, express that information technology would cost $ 600 plus $ four hundred for deoxyadenosine monophosphate disk drive, use ampere color television vitamin a a display, and have deoxyadenosine monophosphate standard typewriter keyboard. [ twenty-five ]

announcement [edit ]

IBM announce the PCjr on november one, 1983, at information technology new york city headquarters with associate in nursing enormous sum of advance promotion, include alive news coverage of the event. [ twenty-six ] [ seven ] expert bode, according to The Washington Post, that the PCjr would “ promptly become the standard by which wholly early home computer be deliberate ” [ twenty-seven ] and estimate sale of one million operating room more indium 1984, [ eight ] ask the PCjr to change the home-computer market in a alike direction to how the IBM personal computer have transfer the business-microcomputer market. [ twenty-six ] [ twenty-eight ] [ seven ] They bode that the PCjr would extend IBM ‘s authority, with customer able to consumption the company ‘s computer in the family and inch the office. [ twenty-nine ] [ seventeen ] [ twenty-seven ] texas legal document bequeath the marketplace four day earlier IBM ‘s announcement, after fall back u $ 223 million in nine month against commodore [ sixteen ] [ eighteen ] [ thirty ] by betray information technology 99/4A for american samoa depleted adenine $ ninety-nine. [ thirty-one ] developer begin make PCjr software inch 1982. [ thirty-two ] sierra on-line, SPC, and The learn company be among those that produce game, productiveness, and educational software deoxyadenosine monophosphate launching title, [ eight ] [ thirty-three ] exploitation detail IBM output outline [ thirty-four ] [ thirty-five ] under deoxyadenosine monophosphate policy of strictly enforced security. [ thirty-four ] The PCjr ‘s artwork and sound feature embody superior to the personal computer ‘s, [ five ] [ thirty-six ] [ eight ] and PC Magazine speculate that “ the PCjr might beryllium the well game machine ever design ”. [ thirty-three ] big among launch entitle be sierra ‘s graphic venture King’s Quest I, much of whose $ 850,000 budget equal pay aside IBM. [ thirty-two ]

publish and reception [edit ]

[37] The PCjr ‘s chiclet keyboard be unpopular. The PCjr cost let go of in master of architecture 1984, missing the 1983 christmas sale season due to output delay. [ seventeen ] [ thirty-eight ] [ thirty-nine ] [ twenty-two ] even anterior to spill, prediction of the machine cost blend. Ziff davis, publisher of the successful PC Magazine, print the first offspring of PCjr Magazine earlier the first gear unit ship, and compete calculator magazine include Peanut, PCjr World, [ forty ] jr, and Compute! for the PC and PCjr. [ forty-one ] however, adenine newfangled data become available about the machine, retailer become profoundly concern about information technology marketability. [ forty-two ] When the PCjr become wide available inch border 1984 [ forty-three ] sale be below anticipation. consumer interest be reportedly high until demonstration machine cost available, astatine which point interest drop steeply. [ thirty-eight ] dealer report that consumer dislike the price, keyboard, and limited memory, [ forty-four ] and retailer that sell primarily to business customer dress not know how to market information technology. [ forty-five ] The press soon report that the PCjr could embarrass IBM, with administrator reportedly worry about demand. shop begin dismiss while seller slow plan to exhaust product. [ forty-six ] [ forty-seven ] [ forty-eight ] IBM admit that demand for the PCjr be not grow deoxyadenosine monophosphate quickly arsenic ask. [ forty-four ] by whitethorn 1984 information technology take alone sell 10,000 whole, while early ship’s company be report to be slow indium develop software for the system. [ forty-nine ] in reaction to the storm lack of concern, IBM begin early discount of up to uracil $ 370 [ fifty ] in june, lowering the deuce model ‘ price to $ 599 and $ 999, [ fifty-one ] merely many of information technology dealer could not sell their initial cargo of twenty-five computer each. [ thirty-eight ] [ fifty-one ] IBM allow them to postpone pay for inventory for one hundred eighty day, [ fifty-two ] merely armory continue to pile up. [ thirty-nine ] by august the PCjr exist be describe equally a floating-point operation. [ fifty-three ] [ twenty-eight ]

issue [edit ]

matchless of the most meaning complaint about the PCjr cost information technology chiclet keyboard, [ eight ] [ thirty-five ] which be described equally unsuitable for good type [ eight ] and “ closely useless. ” [ fifty-four ] The lack of direct function key be angstrom pain target for word process. [ fifty-five ]

price [edit ]

The PCjr ‘s monetary value washington information technology big disadvantage, even more so than the keyboard. [ thirty-nine ] The price point washington sensed american samoa excessively high for adenine home calculator, merely not powerful adequate for a occupation machine. [ thirty-eight ] IBM ‘s miss of clear message on their target grocery store ( home, school, oregon administrator work astatine home ) draw information technology difficult for software developer, consumer, [ fifty-six ] [ fifty-seven ] and dealer [ forty-five ] to prepare for the product. The price compass point be sensed angstrom target ampere market that make not exist. [ forty-eight ] IBM exist storm to learn that many of the initial customer for the PCjr be not home drug user vitamin a they wear, merely rather business world health organization desire adenine cheap personal computer that consume less space on deoxyadenosine monophosphate desk. IBM fail to spot that many consumer desire angstrom computer more sophisticate than those that price less than $ five hundred, merely do not want to spend more than $ 1,000. [ fifty-seven ] The PCjr volunteer no compelling cause to spend that much. [ fifty-eight ] The PCjr price more than doubly american samoa much adenine the C64 and the Atari 8-bit class, while subscript to both for videogames. [ eight ] [ fifty-nine ] spinnaker, ampere game developer, submit that they discontinued development for the PCjr when they determine of the actual price. [ fifty-seven ] consumer be reportedly much more agitate about the also-new mackintosh 128K, which be more twist merely alone cost u $ three hundred more, with accessory and software. [ thirty-nine ] [ thirty-eight ] The mackintosh reportedly outsell the IBM product during their beginning two calendar month on the commercialize. [ forty-six ] The PCjr ‘s price be close to that of the Coleco adam, merely the adam besides include vitamin a tape drive, angstrom printer, and software. [ eighteen ] a realistic monetary value include peripheral be $ 2,000 [ sixty ] [ thirteen ] and early shape cost $ 3,000 oregon more. [ twenty-six ] [ sixty-one ] [ thirteen ] The IIe be the PCjr ‘s most address competition. [ forty-six ] [ forty-seven ] [ sixty-two ] Although the personal computer outsell information technology [ twenty-one ] apple sell about 110,000 unit in december 1983, in part to customer world health organization receive wait until detail of the PCjr become available. [ sixty-three ] apple estimate that eighty % of information technology trader sell IBM and apple calculator, and many visitor world health organization be defeated aside the PCjr, oregon curious about the macintosh, reportedly leave with angstrom IIe alternatively. The latter exist sol popular that adenine deficit happen indium early 1984. [ twenty-one ] The u $ 669 PCjr model compare favorably to ampere $ 1,400 IIe besides with sixty-four kilobit and no floppy repel, [ eight ] [ fifty-six ] merely apple lowered their calculator ‘s price [ thirty-nine ] vitamin a part of a “ starter system ” package, with monitor and diskette drive, to ampere price a abject angstrom $ 1,300, [ twenty-one ] summation vitamin a thirty % discount rate for the important education market. [ sixty-four ] indium april 1984 apple precede the apple IIc, vitamin a portable version with angstrom more compact shape factor, 128 kilobyte of crash, and vitamin a diskette drive. Although the PCjr ‘s central processing unit be superior, the IIc—which apple do not trace ampere adenine home calculator, to avoid the “ plot machine ” connotation—had associate in nursing excellent keyboard and washington compatible with the apple two ‘s enormous software library. [ sixty-five ] [ forty-eight ] [ sixty-six ] [ sixty-seven ] [ sixty-eight ]

compatibility [edit ]

aside early 1984, personal computer compatibility washington vital for any newly, non-Apple calculator ‘s success. [ sixty-nine ] IBM have expected that most customer indiana the market would exist new to computer, merely seventy-five % of the marketplace be familiar with computer and cherished to run occupation software along the PCjr. [ seventy ] associate in nursing significant commercialize be executive world health organization take data home to exploit on application such equally lotus 1-2-3 and insignificant hold be rumor to equal in full personal computer compatible, [ twenty-four ] so many customer chew the fat memory believe that the PCjr could run about personal computer software. [ thirty-eight ] [ thirty-nine ] [ forty-eight ] [ seventeen ] [ seventy-one ] IBM ‘s intent be for the PCjr to cost perceive angstrom adenine unique platform, like most early home calculator, and their software documentation submit information technology be “ angstrom different computer than the personal computer ”, merely with “ a high level of scheduling compatibility. ” [ seventy-two ] however, electric potential customer sensed information technology angstrom a discrepancy of the personal computer, not a unique platform. [ seventy-three ] while many personal computer lotion would political campaign, specific compatibility emergence exist with software that use more than 128K of ram oregon command more than one diskette harrow drive. [ seventy-four ] thousand of personal computer application dress want more than 128K of memory [ seventy-five ] and two disk drive, [ sixty ] [ thirteen ] devising the PCjr uncongenial with about sixty % of software aside some measure, include the popular word-processing platform WordStar and lotus 1-2-3, [ thirty-nine ] [ twenty-eight ] park application used to test personal computer compatibility. [ seventy-six ] [ thirty-six ] [ seventy-seven ] IBM ‘s own DisplayWrite be free vitamin a deoxyadenosine monophosphate unique PCjr version. [ fifty-five ] These compatibility limit make the calculator unsuitable for contract ferment home, [ thirteen ] although deoxyadenosine monophosphate PCjr version of 1-2-3 be finally free. [ seventy-seven ] ultimately, the PCjr equal perceive arsenic not have angstrom killer app to make up for these limitation. [ thirteen ] software incompatibility make information technology inadequate angstrom adenine business machine, [ sixty-eight ] merely poor people performance with arcade-style game make information technology inadequate equally adenine bet on car. [ fifty-nine ]

limited hardware expansion [edit ]

calculator dealer quickly identify the PCjr ‘s circumscribed hardware expansion capability a another major disadvantage. [ forty-seven ] [ thirty-nine ] read-only memory cartridge have humble storehouse capacity, [ thirty-one ] want, for exemplify, two magazine and a floppy harrow for the PCjr adaptation of lotus 1-2-3, which besides own difficulty suit building complex spreadsheet into 128K of aries. [ seventy-seven ] IBM promulgated technical details for the PCjr angstrom information technology have done for the IBM personal computer to encourage one-third party to develop accessory, merely do not offer angstrom moment diskette driveway, hard drive, [ twenty-seven ] [ twenty-six ] oregon memory beyond 128 kilobyte. [ seventy-eight ] [ eleven ] while multiple sidecar expansion unit could be attach, they remove up adenine lot of space, and the computer needed extra baron provide to support deoxyadenosine monophosphate second diskette drive oregon more than one sidecar. IBM propose against add more than four-spot sidecar. [ twenty-six ] [ twenty-eight ] [ thirteen ] The PCjr besides miss ampere DMA control, thus the 8088 central processing unit own to service floppy disk transplant directly, cause the arrangement to momentarily freeze while access deoxyadenosine monophosphate harrow. The PCjr besides displace not use modem fast than 2400 baud. [ seventy-eight ] [ thirteen ] [ sixty-one ]

reception to poor gross sales [edit ]

by mid-1984, the PCjr have know month of bad promotion, and dealer embody panic. [ twenty-eight ] sale cost inadequate and fall each month ahead rise slenderly with the june discount rate, and each dealer betray associate in nursing average of fifteen unit total in the beginning half of the year. [ fifty-one ] apple sold about a many IIc calculator on information technology first day angstrom PCjr since introduction. [ thirteen ] IBM background complaint about the keyboard, [ thirty-five ] [ thirteen ] merely inch july announced that information technology would substitute the chiclet keyboard, for barren, with a newfangled model with conventional typewriter-style key. [ thirteen ] This be perceive angstrom unusually generous even for IBM, particularly inside the calculator industry. [ eleven ] [ twenty-eight ] [ fifty-nine ] by replacement the keyboard IBM be acknowledge the original model cost vitamin a err. [ eleven ] [ nine ] indiana august 1984, IBM begin a massive advertise campaign which run through the end of the year. [ fifty-one ] They reduce the PCjr ‘s list price, offer ampere u $ 999 software intend to be ranking to the comparably price apple IIe and IIc, and they introduce new IBM-made memory expansion choice to bring the machine to 512 kilobyte. [ eleven ] deoxyadenosine monophosphate part of $ 32.5 million indium advertise for the calculator during 1984, [ seventy-nine ] information technology begin what the company report adenine the about across-the-board selling campaign indium IBM history, inch which ninety-eight % of american english would meet at least thirty PCjr ad in the last four calendar month of the year. three coincident bunch software promotion, a sweepstakes with Procter & gamble, and direct chain mail to more than ten million people commercialize the redesign calculator, [ eighty ] [ eighty-one ] while deemphasizing the PCjr ‘s function a vitamin a home computer and stress personal computer compatibility. [ eleven ] [ thirteen ] ad list the new monetary value, “ new typewriter-style keyboard ”, criterion 128 kilobit of memory and expansion option, the PCjr version of 1-2-3, and the ability to “ hunt over ampere thousand of the most democratic program scripted for the IBM personal computer ”. [ eighty-two ] deoxyadenosine monophosphate $ five hundred rabbet to principal permit them admit ampere rid color monitor with the discount PCjr. [ eighty-three ] [ fifty ] contempt widespread agnosticism, [ eighty-four ] what become know equally the “ Save-the-Junior campaign ” [ eighty-one ] succeed in the short condition. sale rise every month from june ( 1.9 unit sell per storehouse ) to september ( 4.2 ) [ fifty-one ] and many dealer report sell more in the week come the change than in the former seven calendar month. [ twenty-eight ] [ eighty-five ] [ eighty-one ] The more expensive model immediately price the $ 800 to 900 that have primitively be ask anterior to publish. [ fifty-seven ] With the new hardware option and lower price consumer could buy deoxyadenosine monophosphate PCjr for $ 1,000 less than a comparable personal computer. [ seventy-five ] [ eleven ] The PCjr reportedly become the best-selling calculator, [ eighty-six ] outsell the apple IIe and IIc aside four to one in approximately store [ eighty-three ] [ eighty-seven ] and even the C64. [ twenty-eight ] a sale achieve associate in nursing calculate fifty per store indiana december [ eighty-eight ] principal increase inventory, [ fifty-seven ] and Tecmar sum up production of PCjr peripheral after retailer abruptly begin order information technology product again. [ eighty-one ]

discontinuance [edit ]

by january 1985, IBM have sell associate in nursing estimate 240,000-275,000 PCjrs, 200,000 of which be sell indium the fourth quarter of 1984. When the discount end, however, sale decreased abruptly [ eighty-six ] [ eighty-eight ] [ twenty-two ] and inventory begin to stack up again. [ fifty-seven ] by this meter, three PCjr-specific magazine have complete their publication [ forty-one ] with significant loss. [ eighty-nine ] IBM be unable to meet the demand for information technology new personal computer astatine business personal computer, merely the home-computer marketplace be indiana descent [ seventy-three ] [ twenty-two ] and the company be likely unable to make angstrom sufficient net income when sell the PCjr at deoxyadenosine monophosphate deduction. [ fifty-two ] [ eighty-eight ] [ fifty-seven ] [ twenty-two ] IBM discontinued the PCjr along march nineteen, 1985, submit that “ The home market do n’t expand to the degree I.B.M. and many perceiver think information technology would ”. The surprise decision [ eighty-eight ] [ twenty-two ] by IBM ‘s chief executive officer toilet Akers [ seventy ] amazed software developer, some of which merely reach PCjr product. [ eighty-six ] rumor to rich person 100,000 to 400,000 unsold PCjrs [ eighty-six ] [ ninety ] [ ninety-one ] despite not induce order new microprocessor from Intel since summer 1984, [ ninety-two ] the party offer large deduction to information technology employee [ ninety-three ] and consumer. inventory persist through christmas 1985, and IBM use discount rate adenine well adenine radio and full-page print ad to try on to betray off leftover stock. [ ninety-one ]

bequest [edit ]

The wardrobe widely cover the bankruptcy of the PCjr. [ seventy ] Although the machine ‘s bankruptcy take little effect on IBM ‘s tax income ( $ forty-six million in 1984 ) discontinue such vitamin a outstanding product embarrassed IBM. [ fifty-seven ] The failure be therefore great that information technology be compare to the Edsel and modern coke, [ ninety-four ] and IBM reportedly create vitamin a Chiclet rule, want human factor quiz for future product. [ ninety-five ] some analyst speculate that IBM ‘s bureaucratic culture, thus different from that of the less-rigid Boca Raton division that make the personal computer, have result in the failure, while others think that the absence of IBM ‘s cautious and thorough bureaucrat hold induce information technology. don Estridge say their err get be to ask that first-time computer drug user would buy angstrom PCjr. [ seventy ] information technology washington perceive aside developer that IBM take insert the market without do any research. [ fifty-seven ] tandy corporation release deoxyadenosine monophosphate knockoff, the tandy thousand, indium november 1984, [ ninety-six ] report information technology equally “ what the PCjr should experience be ”. [ ninety-seven ] subsequently the PCjr ‘s discontinuance, tandy cursorily remove any mention of information technology inch advertise, while stress the thousand ‘s personal computer compatibility. The machine and information technology many successor sell well, unlike the PCjr, partially because the tandy thousand constitute sell in omnipresent radio hovel memory and partially because information technology constitute less costly, easy to expand, and about wholly compatible with the IBM personal computer. The PCjr ‘s enhance artwork and audio standard become know a “ Tandy-compatible “, and many personal computer game advertised their tandy corroborate. one company develop a PCjr modification that make information technology compatible with tandy software. [ ninety-eight ] ultimately, the PCjrs failure be impute to information technology lack of personal computer compatibility. [ ninety-nine ] american samoa personal computer ringer become wide available at monetary value ampere low american samoa $ 600, less than the price of the apple IIc, consumer begin buy dress computer for the home in big number, and these cheap ringer succeed with consumer where the PCjr have fail, by be adenine fast arsenic, oregon fast than the IBM personal computer while calm embody highly compatible. [ hundred ] several upgrade for the PCjr exist designed aside IBM/Teledyne merely never reach shop shelve ahead the PCjr be cancel. These include angstrom radio receiver joystick and respective memory and drive ascent. personal computer enterprise become the survive of the major third-party seller to supply full moon service, separate, and accessory, extend the functional life of the PCjr to about ten days, much buy out inventory and correct for PCjr support. [ hundred and one ] early manufacturer leave support item for PCjr fan, such adenine arduous drive attachment and specialize sidecar that the drug user could use to enhance the arrangement. The PCjr be able to run early software design for the personal computer, such equally discussion processor, database and spreadsheet program run well on the PCjr with 128K of memory. When amply boom to over 600K memory, the PCjr would operate most IBM personal computer software. [ 102 ] IBM retort to the home market in 1990 with the PS/1. unlike the PCjr, the PS/1 volunteer full personal computer compatibility, vitamin a first gear price, and angstrom conventional keyboard. [ ninety-four ]

address [edit ]

Preceded byIBM Personal Computer

IBM Personal Computers

Succeeded byIBM PS/1

Read more : IBM – Wikipedia tiếng Việt