--- title: IBM PC Junior categories: - Computers types: - Home Computer origins: - U.S.A. years: - '1983' cpus: - Intel 8088 params: name: PC Junior image: /media/museum/photos/ibm_pcjr_system_1.jpg company: /companies/ibm company_name: IBM specs: - label: NAME value: PC Junior - label: MANUFACTURER value: IBM - label: TYPE value: Home Computer - label: ORIGIN value: U.S.A. - label: YEAR value: November 1983 - label: END OF PRODUCTION value: March 1985 - label: KEYBOARD value: Chicklet keyboard (full stroke keyboard was available later) - label: CPU value: Intel 8088 - label: SPEED value: 4.77 MHz - label: CO-PROCESSOR value: Texas Instrument sn76496 n (sound) - label: RAM value: |- 64k (up to 640 KB)\ Extended model : 128k - label: VRAM value: from 2k to 128k (use the conventional RAM) - label: ROM value: 24 KB - label: TEXT MODES value: 40 x 25 / 80 x 25 - label: GRAPHIC MODES value: 160 x 200 (16 colors), 320 x 200, 640 x 200 - label: COLORS value: '16' - label: SOUND value: three channels - label: SIZE / WEIGHT value: Unknown - label: I/O PORTS value: 2 cartridges ports (64 KB each), Centronics (optional), RS232, Joystick, Light Pen, video out (RCA plug) - label: BUILT IN MEDIA value: one 5.25'' disk drive - label: OS value: MS DOS - label: POWER SUPPLY value: External PSU - label: PRICE value: Unknown tabs: - photos - adverts - hardware - software - links - docs photos: - title: IBM PCJR IN ALL ITS GLORY subtitle: '' text: Picture courtesy of Verault ebay seller image: /media/museum/photos/ibm_pcjr_allglory_1.jpg - title: MAIN UNIT subtitle: '' text: '' image: /media/museum/photos/ibm_pcjr_system_s3.jpg - title: COMPLETE SYSTEM subtitle: '' text: Complete system with its massive AC adaptor and a monochrome composite monitor. image: /media/museum/photos/ibm_pcjr_withmonitor_s1.jpg - title: PRO VERSION subtitle: '' text: This model is equipped with a PC professionnal keyboard, a second disk-drive unit on top of the computer, and a RAM expansion plugged to the right of the case. image: /media/museum/photos/ibm_pcjr_4.jpg - title: SIDES subtitle: '' text: On the right side, the JrCaptain sidecar expansion provided 128 KB RAM expansion, a standard Parallel printer interface and a real time clock. image: /media/museum/photos/ibm_pcjr_sides_s1.jpg - title: PCJR COLOR MONITOR subtitle: '' text: Thanks to **Edwin Amsler** image: /media/museum/photos/ibm_pcjr_colmonitor_s1.jpg - title: ORIGINAL CHICKLET KEYBOARD subtitle: '' text: '' image: /media/museum/photos/ibm_pcjr_keyboardbox_1.jpg - title: 'SECOND KEYBOARD #1' subtitle: '' text: Below the typewriter keys, this second version also used a rubber membran. image: /media/museum/photos/ibm_pcjr_keyboard_s1.jpg - title: 'SECOND KEYBOARD #2' subtitle: '' text: The keyboard could be either connected to the main unit by a standard cord, or used without cord, from a distance up to 6 meters, thanks to its dual infrared LEDs. image: /media/museum/photos/ibm_pcjr_keyboard_s2.jpg - title: REAR SIDE subtitle: '' text: |- **(1)** Parallel connector from the JrCaptain sidecar expansion\ **(2-3)** Joystick connectors\ **(4)** Printer connector\ **(5)** Keyboard connector\ **(6)** Light pen connector\ **(7)** TV set connector\ **(8)** Conposite video output jack\ **(9)** Optional modem hole\ **(10)** IBM Colour monitor connector\ **(11)** Serial connector\ **(12)** Tape recorder connector\ **(13)** Power connector and switch\ **(14)** External audio jack. image: /media/museum/photos/ibm_pcjr_rearside_s1.jpg - title: OPENED subtitle: '' text: |- **(1)** Power supply card\ **(2)** 128 KB expansion card\ **(3)** Floppy drive controller card\ **(4)** Infrared receiver. image: /media/museum/photos/ibm_pcjr_inside_s1.jpg - title: 'MOTHERBOARD #1' subtitle: '' text: |- **(1)** Buzzer\ **(2)** Tape recorder remote control relay\ **(3)** Various I/O chips from Intel, AMD and NEC\ **(4)** Motorola 6845 display controller\ **(5)** Custom IBM memory management chip\ **(6)** Power card connector\ **(7)** Memory expansion connector\ **(8)** 64 KB RAM chips (8 x 4164)\ **(9)** Infrared receiver\ **(10)** Modem card (left) and FDD controller card connectors\ **(11)** 24 KB ROMs, hold the Cassette BASIC interpreter\ **(12)** ROM cartridges connectors\ **(13)** Bus expansion connector\ **(14)** Intel 8088 microprocessor. image: /media/museum/photos/ibm_pcjr_mainboard_s1.jpg - title: 'MOTHERBOARD #2' subtitle: '' text: Close-up view of the infrared receiver and dual cartridge connectors. image: /media/museum/photos/ibm_pcjr_mainboard_s2.jpg - title: PCJR MANUALS subtitle: '' text: '' image: /media/museum/photos/ibm_pcjr_manuals_s1.jpg - title: SAMPLER DISKETTE subtitle: '' text: |- Cover of the Sampler diskette.\ Typical pictures of the personal computer use of the time: Business, home, school, for people of all ages. image: /media/museum/photos/ibm_pcjr_samplerdisk_s1.jpg adverts: - title: 'ADVERT #1' subtitle: '' text: '' image: /media/museum/pubs/ibm_pcjr_pub_1.jpg hardware: - title: ADAPTER CABLE FOR SERIAL DEVICES subtitle: '' text: This IBM PC jr option allows many serial devices to be connected, such as printers and external modems. image: /media/museum/hardware/ibm_pcjr_serialadaptbox_1.jpg - title: ADAPTER CABLE FOR THE IBM COLOR DISPLAY subtitle: '' text: This IBM PC jr option allows you to attach the IBM Personal Computer Color Display to the IBM Pc jr system unit. image: /media/museum/hardware/ibm_pcjr_color-display-cable_box_1.jpg - title: BASIC CARTRIDGE subtitle: '' text: Thanks to **Edwin Amsler** image: /media/museum/hardware/ibm_pcjr_basiccart_s1.jpg - title: 64K RAM EXPANSION subtitle: '' text: This add-on doubles the existing RAM of the PC Jr. System and provides 80 Column text support. image: /media/museum/hardware/ibm_pc-jr_64k.jpg - title: 128K RAM ''SIDE-CAR'' EXPANNSION subtitle: '' text: The expansion is plugged on the right side of the main-unit. Several expansions could be plugged to each other like this. image: /media/museum/hardware/ibm_pcjr_128k_extension.jpg - title: 3 SIDE-CAR EXPANSIONS subtitle: '' text: Here there are 3 side-car extensions plugged into each other on the right side of the main unit (2 128k RAM extensions and 1 printer interface). image: /media/museum/hardware/ibm_pcjr_triple_extension.jpg - title: PARALLEL PRINTER ATTACHMENT subtitle: '' text: This unit is used to use any parallel printer with a PC Junior. It plugs onto the right-hand side of the computer. image: /media/museum/hardware/ibm_pcjr_parallel-printer-attachment_1.jpg - title: JOYSTICK subtitle: '' text: This joytsick is only compatible with the PC Junior image: /media/museum/hardware/ibm_pc_junior_joystick.jpg - title: JOYSTICK BOX subtitle: '' text: '' image: /media/museum/hardware/ibm_pcjr_joystick-box_1.jpg - title: JOYSTICK PINOUTS subtitle: '' text: |- 1 - +5v DC\ 2 - Res. Y-Axis\ 3 - Logic ground\ 4 - Key\ 5 - Fire button\ 6 - Fire button\ 7 - Res. X-Axis\ 8 - Shield ground image: /media/museum/hardware/ibm_pcjunior_joystick_pinout.gif - title: COMPACT THERMAL PRINTER subtitle: Model 5181 text: '' image: /media/museum/hardware/ibm_pcjr_compact-thermal-printer_1.jpg screenshots: - title: CROSSFIRE subtitle: cartridge label text: '' image: /media/museum/software/ibm_pcjr_crossfire-cart.jpg - title: MINESHAFT subtitle: cartridge label text: '' image: /media/museum/software/ibm_pcjr_mineshaft-cartridge_1.jpg - title: KING'S QUEST subtitle: cartridge label text: Thanks to James R. Skinner for this picture image: /media/museum/software/ibm_pcjunior_kingsquest.jpg links: - title: Forever70...80...90... url: http://perso.wanadoo.fr/fabrice.montupet/ibm.htm text: Nice page about the PC junior (french) - title: Mike's PCjr Page url: http://mail.magnaspeed.net/~mbbrutman/PCjr/pcjr.html text: Too much things in there to lis them all. Go & visit! - title: PC Jr Reborn! url: http://www.micro-zone.com text: Forums, Software, News, Links and more - title: PCjr.org url: http://www.pcjr.org/ text: Very complete site, worth a visit docs: - title: GUIDE TO OPERATIONS url: null cover: /media/museum/docs/couvs/ibm_pc-jr_guide-to-operations.jpg text: |- **GUIDE TO OPERATIONS**\ written by IBM  compiled/archived by Eric Bylenga\  type of document : PDF\  source : www.old-computers.com comments: - author: Cuvtixo (Colorado/USA) date: Sunday 25th October 2020 text: Yan touches on some good points, but... the first point about "incompatibilities" misses a lot about the market it cam out in. Compaq would not bring out its successful Deskpro 386 until the next year, 1986. Apple II, Comodore64, Atari, TRS-80 and other computers of the time were all incompatible and idiosyncratic. Even when they had 5.5'' disks, the formats were incompatible. In truth having IBM DOS 2 and not CP/M made them weird at the time (IBM offered CP/M for an additional price on the day the 5150 came out) But yes, they did fear PCs eating into business computers, that''s why they accepted Microsoft''s OS and left them free to licence. From the beginning they thought they could make their own later (OS/2) and crush M$. Also with PS/2 line they would put out a new MCA architecture and crush the new ISA standard their clone competitors made. Also their was a lot of criticism about the awful "chiclet" keyboard. It was so bad, PC makers avoided the style for years afterwards. Basically until Apple came out with the Magic keyboard, in the 2000s which won acclaim and is still sold at premium prices. It''s an irony many seemed not to realize. Above all, was IBM''s arrogance. Picking out the smaller faults sometimes misses this larger point. - author: Jay (Washington State USA) date: Tuesday 22nd September 2020 text: Email is jaya.buckwheat@gmail.com - author: Jay (Washington State USA) date: Tuesday 22nd September 2020 text: I am looking for one of these at a cheap price, I will pay up to 100$ including shipping if I have to pay for it - author: Yan date: Monday 2nd December 2019 text: with so many oddities in comparison with the standard PC is not surprise that it has failed. I don''t see the point of a company picks a successful product, make a worse version of it and expect that people will swallow it. They could simply put the very same hardware into a cheapo and more compact case and sell it for less - surely it would be a better way of hooking the home users, and, of course, work hard developing a plethora of cool games (it always was the main attractive for computer home users by that time). I believe that they thought about this but feared that the corporate customers noticed the similarity and buy the JR for office use instead the regular version. Anyway, it is only history now and we all know that it was just a matter of small time until people start buying the "big" PC to use at home! $) - author: Don (Virginia USA) date: Saturday 2nd February 2019 text: I have a PCjr for sale - original boxes, 2 keyboards, 2 joy sticks, 8 games, 10 magazines and all original books - guide to Operations, Basic book, Hands on Basic, IBMPCjr sample disk. - author: dlblake (usa) date: Sunday 2nd April 2017 text: I had an IBM JR and added the racore side extension and a 20MB hard drive with 640K ram. I used it up to 1992. It worked quite well. I finally had a power problem with house 60A service and it finally died. - author: CharonPDX (Cascadia) date: Thursday 15th September 2016 text: |- Mike from Rochester, I was gong to point out to you the somewhat recent jrIDE, then I realized who you were, well, duh, of course you know about it now, you helped make it happen! (For those who are curious, here is the thread on Mike''s own forums detailing the creation of an ATA adapter for the PCjr: http://www.brutman.com/forums/viewtopic.php?f$1$t$180 - author: computer guy date: Saturday 4th February 2012 text: |- Here is a section from computerhope.com:\ In 1822, Charles Babbage purposed and began developing the Difference Engine, considered to be the first automatic computing engine that was capable of computing several sets of numbers and making a hard copies of the results. Unfortunately, because of funding he was never able to complete a full-scale functional version of this machine. However, in June of 1991 the London Science Museum completed the Difference Engine No 2 for the bicentennial year of Babbage''s birth and later completed the printing mechanism in 2000. And, the first electrical computer was the Z1, built by Konrad Zuse from 1936 to 1938. - author: Dan (Minnesota) date: Sunday 4th December 2011 text: My mom uses our PCjr to save cooking recipes at least up till the past few years. I don''t know how well the disks are holding up though. I''ll ask her next time I see her. - author: Mike (Rochester, MN) date: Wednesday 8th August 2007 text: |- Hardcard in a Jr? Probably not ... People did graft hard drives onto the machines in many different ways so I wouldn't rule it out, but no company did a HardCard type of solution for a PCjr. Now, grafting an MFM controller from an XT onto a Jr, that we can help you with. ;-) Or maybe SCSI instead? :-) - author: Guyy (Upstate Ny) date: Friday 22nd June 2007 text: I never got to test this, but as I rambled through some later computer junk I noticed I had some 20mb HardCards with pinsets that matched those in the PCjr. I never had a monitor so I dont know if it worked but if anyone knows what Im reffering to, could the HardCards have actually been supported by the PCjr? Just want to settle the idea in my head. - author: william pociengel (wisconsin) date: Monday 30th April 2007 text: |- I just got rid of the monitor for mine. I still have the machine. I also (somewhere) have a case of sidecars (memory or ports I don't recall which) unopened. stock this was FASTER than a PC and you could add an 8087 by piggybacking a chip and then tying one pin (I forget which) that made it active. I still have an 8087 I bought as an extra. I also have a cartridge which provided encryption (it's marked as not for export) I believe it's identified as a munition. I'll try to remember to get photos and such if someone reminds me ;-) - author: David Blake (USA) date: Thursday 4th January 2007 text: I believe I bought the JR for around 1000.00 with a printer. I added the side card with 512K memory and a 20 mb hardrive this all put the total up to about 1500. I ran it for about 8 years with all dos and up to windows 95. It really worked well and just as good as other machines. a Power failure in home took out part of the power supply and it was replaced with P2 MOB and machine - author: Bettina (Bay Area) date: Monday 27th November 2006 text: Hello, I am interested in buying a PC junior that works from someone. Please e-mail me. - author: Jeffrey H. Ingber (FT. Lauderdale, FL) date: Wednesday 18th December 2002 text: The jr is still one of my favorite machines, and I still collect jr hardware and software that I happen to come across. This was one of the most interesting machines from the early PC period. - author: Brandon Higa (USA) date: Thursday 15th August 2002 text: |- Actually, the Function keys on the PCjr worked a little differently from the Control key-combination. Function (Fn) didn't need to be held down - you pushed it once, then pushed the other key (PgUp, PgDn, Home, End were the cursor keys) to get the desired result. A few games didn't like this, since the way Fn was handled created different Make/Break sequences from a "normal" keyboard. If using the chiclet keyboard, the keyboard cable was a must because it ate batteries like crazy. One cool thing was the auto Diagnostics you get from Control-Alt-Insert. If you had a 'standard' (83-key) keyboard like I did you could test that too.\ Also, you could shift the entire screen left/right with Control-Alt-LeftArrow and Control-Alt-RightArrow. Since the PCjr didn't have NMI, you couldn't enter keystrokes into the keyboard buffer while disk access was occuring. It resulted in an annoying "beep" - there were some third-party devices that you could get to avoid this. I had a cartridge which had a small buffer to "emulate" NMI, and also had keyboard status lights (CapsLock, ScrollLock, and something else I can't remember). I don't have my PCjr anymore, but I have lots of good memories from the time. I had 768k of RAM, a 720K floppy drive (PC Enterprises), had done the Tandy graphics mod, had the "thin font" ROM modification installed, NEC V20 9.54Mhz CPU upgrade, and had the status/NMI cartridge I mentioned above. I once wrote a small utility called JrSound that would switch one of the registers to make certain Tandy 1000 games that played without sound on the PCjr actually have sound. Unfortunately, I can't find it on the 'net anywhere... If someone happens to have this utility, I'd appreciate you sending me an email. I'm just feeling nostalgic... Cartridge BASIC ruled... though it saved files in a strange IBM-only way unless you saved with ,A (I think that was the switch...) I ran DOS 2.1, 3.1, 3.3, and 3.33 on my PCjr.\ I had a Mouse Systems optical mouse that required a special metal mousepad that had a grid of red/blue lines on it and PCjr ColorPaint cartridge. Had two PCjr joysticks too. The PCjr joysticks had little switches that would disengage the auto-centering for each axis. I had some football game cartridge that used the PCjr's 3-voice sound for speech synthesis too. It'd say "It's good" or "Touchdown" and have some simulated crowd applause. It was so high-tech at the time. =) - author: Robert Luther (Earth) date: Sunday 12th May 2002 text: I own 5 still working PCjr's. one was fixed up and has a external 4.3 gig hard drive and a CD-rom. it even boots from the hard drive. also the speed of this computer has been speed up to 9.54 mhz. also i have a large colection of software that runs on the jr including WINDOWS 3.0. I also have converted my 5.25 360k drive over to a 3.5 720k systemi am still aquireing old hardware for the jr and am looking for a mega board. this brings the PCjr's memory up to 1736kram ( most of the memory can be used for a ram disk) - author: GriffJon (USA) date: Tuesday 5th March 2002 text: The PCjr could handle most DOS of it's era that you put on the floppy during boot. I ran 1.1, 2.1 and 3.1 on it at various stages (to support various games). It could also take an analog joystick. oc_id: 186 source: url: https://web.archive.org/web/20230130041031/http://www.old-computers.com/museum/computer.asp?c=186 date: '2023-01-30' --- After launching the [IBM PC](/museum/ibm-pc-model-5150/) (and its great success), IBM tried to stand out a standard for home computers, it created then the PC junior, which itself is a "light" version of the PC especially designed for home activities. Despite its qualities, the PC jr had few success and never managed to replace the established home computers like [Commodore 64](/museum/commodore-c64/), [Apple II](/museum/apple-ii/) or [Atari 800](/museum/atari-400/). Two IBM PC junior models were available: a basic one and a enhanced one (supplied with 128k, 30 programs, a 5.25" floppy disk drive \[360 KB\] and its controller). Contrary to the IBM PC, the power supply is not integrated to the case, but is external. The keyboard is linked by infra-red to the CPU, though there was a RJ11 (standard phone jack) plug that could be used instead to save batteries. It is impossible to connect a 8087 math co-processor. The RS232 connector is not a standard one. To use a standard RS232 device, the user has to buy a special adapter ("Berg" style connector breakout -> D25 connector). The PC Jr runs under MSDOS 2.1 (the same version as the PC) and handles a hard disk when it is not possible to connect hard disk on the PC Jr (go figure)! There was an internal modem available that ran at 300 bps sold by IBM. Third party modems were also available at 1200bps. A cartridge containing enhanced basic (with special graphics instructions) was also available. To get a 80 column text display, the extra 64k RAM expansion is needed. Many IBM PC programs would not originally run on the PCjr because it did not include a DMA controller. This was available through a memory side-car add-on from Tecmar Systems. Many people were able to then run the PCjr as a competent business type of system as well.