The Original IBM PC 5150 - the story of the world's most influential computer

  • Published on Jul 18, 2018
  • This is the story of the first IBM PC - the computer that's the original ancestor of one you probably still own. Today, nearly 40 years after its introduction, modern PC's are used for everything from the kinds of business applications the system was originally designed for, to scientific work, to high-end gaming. But it all started back in 1981 with the IBM 5150.
    If you're looking for a more personal take on this computer, watch for my upcoming review of this IBM 5150!
    If you want your own IBM PC, they're not cheap but they are plentiful on Ebay, and I'd love it if you used my affiliate link:
    Some credits for some of the images and other things used in this video:
    buckling spring: By Shaddim - Own work, CC BY-SA 3.0,
    Pet: By Photograph by Rama, Wikimedia Commons, Cc-by-sa-2.0-fr, CC BY-SA 2.0 fr,
    Atari 400: Evan-Amos
    Atari 800: Evan-Amos
    TI 99/4 Tocchet22
    Vic 20: Evan-Amos
    Heathkit H88: Arthur G Korwin Piotrowski
    CGA card: Malvineous
    Datamaster ad: Adtari
    PC ad(s): La Mazmorra Abandon
    5120 ad: Adtari
    5100 ad: Magdy Ragab
    PC XT photo: Ruben de Rijcke:
    PC AT photo: MBlairMartin
    Model F AT: daedelus
    PowerPC 601: Dirk Oppelt
    Portable PC: Hubert Berberich
    There You Go by Audionautix is licensed under a Creative Commons Attribution license (
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  • Science & TechnologyScience & Technology

Comments • 711

  • Modern Classic
    Modern Classic  Year ago +97

    Hey guys - one quick clarification about something that's getting a few comments. In the video I say that the PC was 2-4 times faster than its competitors at tasks important to businesses. Keep in mind that I was not comparing clock cycle vs. clock cycle of the CPU alone against only certain other CPU's (I showed more than CPU speed in the chart); I was comparing overall performance in real-world tasks. As we all know even today, there's more to a computer than just its CPU, and the fact that the PC had a very advanced graphics subsystem, support for massive amounts of RAM (for the day) that reduced or eliminated the PC's need to access a disk while within an application, a fast system bus, math co-processor support and a faster floppy and hard drive interface than its competitors, made it much faster overall than those machines at tasks important to businesses (for example, large spreadsheets or relational databases).
    Of course, that doesn't mean that some of the machines on my list weren't better at certain other tasks - I'm a big Atari 8 bit and Apple II fan, personally (and am an Apple II owner since 1985), and would choose either of those machines to play games on before the early PC. In fact, I actually made that choice - I chose my Apple IIc at a time when the PC AT was already available!

    • AIO inc.
      AIO inc. Month ago

      The PC's graphics subsystem was terrible - Monochrome text or extremely low resolution color. It's only advantage was 80 columns, which the Apple // could also do.

    • Daishi5571
      Daishi5571 Month ago

      @Scali Bohemiq LOL I read your post but was a bit confused, then I re-read what I wrote, opps! I wrote "it was a majority of the 16K" and I have know Idea why I wrote that, It's not even a spelling mistake. I knew that it didn't use a majority of that memory (perhaps if I had used a little of my own) I have edited the post to reflect what I should have written. I guess my mistake was writing it while tired enough that I went directly to bed once sent (I don't normally do that) thanks for the correction and the extra detail.

    • Scali Bohemiq
      Scali Bohemiq Month ago +1

      @Daishi5571 The boot ROM only need a few kb to store some basic state variables. I believe it requires less than 2k (and the first 1k of that is the interrupt table that any x86 system needs). In theory you could create your own bootable floppy, without DOS. So a 16k machine with floppy could theoretically work. You can't boot from cassette though. You'd need to boot into BASIC first, and then you can use the cassette. BASIC also only needs just a few kb.

    • Scali Bohemiq
      Scali Bohemiq Month ago

      @Daishi5571 The 16k base model did not have a floppy drive, because it couldn't run DOS anyway. For DOS you required 32k at least, and a floppy drive obviously. The first versions of DOS took about 20-25k of memory. I believe the most basic DOS configurations were sold with 64k.

    • Scali Bohemiq
      Scali Bohemiq Month ago +1

      @Crescendo I disagree. For people who want to play games (or use a GUI), these things do matter. They may not understand the technicalities in the way the programmers do. But they can surely tell which platform has the better sound and music and general performance in games. As for your comparison with the Amiga, I have no idea where that came from (I specifically talked about 8-bit, and the Amiga is not an 8-bit machine)... Firstly, the Amiga is from 1985, not 1990, and the IBM PC/XT 5160 was introduced in 1983, and still sold until 1987. So it did in fact compete with the Amiga to some extent. However, the main competitor would have been the C64 obviously (which has raster interrupts, custom character sets, hardware sprites and scrolling). Again, I was merely responding to the phrase "the PC had a very advanced graphics subsystem", which simply isn't true. Only a fanboy would then argue about how you don't need any kind of graphics hardware. Is the poor graphics hardware acceptable to certain users? Certainly. History has pointed out as much. What is your point?

  • Arie
    Arie Day ago

    This was the first "Real" computer that I used in the 80's. Our neighbor had one with this very same monitor and the local library had one with a CGA monitor and people could sign up for it for an hour. That keyboard still feels better than many computers today. During the 90's I found one in the dumpster and cleaned it up and used it to get on BBSes and found a "modern" 486 to buy from someone online and then ended up throwing the IBM back in the dumpster because it was so old but I really wish I hadn't. It deserved better.

  • Jerry S
    Jerry S 3 days ago

    Mary Gates, Bill's mother sat on the board of United Way with John Opal. Bill had a small software company, and IBM originally gave "Mary's boy" the job of writing the Basic interpreter for the new system. After difficulties negotiating with Gary Kildall, Bill got the operating system too. He bought and modified a DRI clone called QDOS for the new PC.

  • Benjamin Brady
    Benjamin Brady 6 days ago +1

    We need more Steins; Gate comments, so I'll just leave this here

  • George Mavrommatis
    George Mavrommatis 8 days ago

    Amazing video :)

  • Craig Manning
    Craig Manning 28 days ago

    I worked on the system 36, then the system 38, and then the first AS/400. Still plenty of I-Series in use to this day.

  • Phil P
    Phil P Month ago

    What a wonderful piece documenting the origination of the PC! Bravo!

    SHADOW FOX Month ago +1

    Nice to meet you, it is Japanese. Was first seen, this is the beginning of IBM's personal computer.
    I also once had be using a personal computer called Aptiva560.

  • Icy The Fox CK
    Icy The Fox CK Month ago

    the computer is wuus liked bank 2:32

  • Crescendo
    Crescendo Month ago +1

    One of the best introductions to the PC I've seen.

  • Programmatic Modeling Consultants

    The first desktop personal computer (as marketed) was more like a programmable calculator and appeared in 1968:

  • Ray Brown
    Ray Brown Month ago +1

    I disagree. The Apple II was more influential.

    • Modern Classic
      Modern Classic  Month ago +1

      Which is why we're all still running Apple II compatibles!

  • Hugh Moore
    Hugh Moore Month ago +1

    Backward Compatibility ? ! ?
    Is that anything like 20/20 hindsight ? ? ?
    Reverse Engineering ? ? ?
    Or is it just plain . . . should of . . . would of . . . could of ? ? ?

  • Charles B
    Charles B 2 months ago +1

    I worked for a software company that got a beta version in late 1980 to port our apple and commodore software over. I stil have one today. They were grand times, we felt like masters of the universe.

  • Hugh Moore
    Hugh Moore 2 months ago +1

    The 5150 was often referred to as the . . . XT
    and there were a lot of them out there . . .
    Mine came with only one 5.25 floppy drive . . .
    but I quickly added a second . . .
    I blew it up by plugging in a card that was probably built for some other device but happened to fit the card slot . . . 8(
    It was an amazing machine by any standard and I sometimes wish I still had one ! ! !

  • Jack Headroom
    Jack Headroom 2 months ago


  • willrsan
    willrsan 2 months ago +3

    This history is utterly fascinating because my dad had one of the original IBM XT "portable" machines which was my formative computer experience and now I am watching this on a descendant of the original PC. The keyboard I am using came with a NEC server and is obviously a direct clone of the IBM model M keyboard in layout and color. As to the PC I am using - it is running Windows 10 ( descended from MS DOS) has an Intel CPU ( a XEON X5650) has an ASUS ROG motherboard with Intel X58 chipset, all 10 year old tech but still works great - basically a mix and match of components conforming to some loose standard. If I could travel back in time to the late 70s and early 80s I would tell those early computer designers from Commodore, Atari, Apple and whoever that a successful computer has to be open and expandable and upgradeable in order to be successful as I am from the future and have seen what works. The PC lives on!

  • Lorenzo Marini
    Lorenzo Marini 2 months ago +1

    Programma 101 by Olivetti was the First personal computer

  • Prog Metal Musician
    Prog Metal Musician 2 months ago

    Absolutely fantastic historical video. Thanks!

  • Banzuko OGK
    Banzuko OGK 2 months ago

    Where its " Mark Dean" name in any of this??

  • Robert Jensen
    Robert Jensen 2 months ago

    At the time Apple was going to introduce the Lisa computer there was an assembler also named 'LISA' written by Randy Hyde, for the Apple ][. So Apple gave Randy one of those $10,000 Lisa computers in exchange for the rights to use the name, Lisa. I believe Randy taught computer science at UC Riverside. He was one of the founding members of the Original Apple C.O.R.P. the first Apple computer club which met at CSULB and later moved to UCLA. (I was one of the very early members)

  • pulesjet
    pulesjet 2 months ago +1

    I'm typing on a POS Lenovo at this moment. Built Nothing like the old Think Pads. They too have gone with the Built in battery and unObtainium Spare Parts. Zero Chances of Memory or any other Upgrades. Zero Provisions to do so. No I won't be buying another.

  • pulesjet
    pulesjet 2 months ago +1

    Unlike Apple IBM maintained the Open Architecture and you could do stuff with them.. Apple shot them selves in the Foot Going Absolute Proprietary EVERYTHING. Hell you can't even change the battery any more.

  • christian gibson
    christian gibson 2 months ago +1

    Back in 1974 as a young software engineer I switched jobs from Philips in the Netherlands to the University of Leiden, Centraal Rekeninstituut. Shortly after joining the CRI I was allowed to take home our first acquisition to try it out. I didn't realize that this was historical! It was an IBM 5120 portable computer (programmable in Basic). It was a real PC - and probably the first PC in the world, coming as it did around 6 years before the famous IBM PC which launched in August 1981...

  • Ian Joyner
    Ian Joyner 3 months ago

    Saying the IBM PC is the world's most influential computer is giving it way too much credit for a machine that could be designed by any two kids in a garage and one for which they completely forgot about software, especially an OS. There has been much else happen in the computing industry that has been as or more influential. Videos like this try to ignore the true history.

    • Ian Joyner
      Ian Joyner 2 months ago

      ​@willrsan "There was Jobs and Wozniak" you answered your own question.
      No, the IBM PC was completely underwhelming. What sold it was the three letters "IBM" on the front. IBM took the slot idea from the Apple II. It was based on the 8088, not 8086 like many other machines that were available (as one Convergent Technologies/Burroughs C/B20 which really were impressive machines).
      IBM's goal for this machine was to put Apple and other competitors out of business. It did not have to do that technically - IBM could use its market clout. That does not make for a technically good or impressive machine.
      "The PC remains possibly the most important computer in history."
      That statement is laughable.
      "That I am using a machine right now descended upon the original PC proves this to me."
      That is very flimsy evidence. You are more using a computer now that descends from the Macintosh. Computing is about software not hardware - and let's see, IBM completely forgot about software and got DOS from Gates who bought QDOS (Quick and Dirty OS) from Seattle Computer Systems. This proves my point that the IBM PC was really some kind of sick joke that in fact derailed many of the good things going on.
      That so many people - like you - believe the IBM PC to be the most important computer in history is rather sad.

    • willrsan
      willrsan 2 months ago

      So where were "those 2 kids in a garage"? There was Jobs and Wozniak and they did their thing and we now have the Apple line but where were the other "2 kids". Just because a computer of the original PCs complexity could be designed today relatively easily does not mean the original was not a feat of engineering, skill, timelyness, luck and whatever . The PC remains possibly the most important computer in history. That I am using a machine right now descended upon the original PC proves this to me.

    • Ian Joyner
      Ian Joyner 2 months ago

      @Modern Classic And Windows would not be Windows without the Macintosh. When you use Windows you are using something based on Macintosh, so Macintosh has been more influential than the IBM PC. The IBM PC Brough you MS-DOS based on QDOS (Quick and Dirty OS from Seattle Computer Systems) hardly good breeding. It was only influential because of IBM's market dominance.

    • Modern Classic
      Modern Classic  2 months ago +1

      And yet most of us are using IBM-compatible computers today (except for the 9.71% using Macs). So...

  • BitVolt
    BitVolt 3 months ago

    you really don't like apple I see.

    • Modern Classic
      Modern Classic  2 months ago

      You haven't watched any of my other videos I see.

  • TubiCal
    TubiCal 3 months ago

    What a great summary....i was given (!) a IBM XT around the early 90s...and when i opened it, it had a paradise VGA installed...this VGA card alone must have cost a fortune...sadly i needed its space back and also gave it to another computer freak, as we call us...i still use a model M keyboard right now to type this survived 4 PCs and still have the best feel compared to all these newer and newest gaming "blinky-blinky" flimsy keyboards. During my programming days (mainly C) i hit its keys with my fist, really hard, the only thing happened was that my hand hurts badly...the keyboard seems to not even sensed at some point i simply quit doing that...;)

  • WillieRants
    WillieRants 3 months ago

    Excellent video for what must be the most under rated channel on RU-clip. Sub, Like, Share. Let's get the word out!

  • Patti Brooks
    Patti Brooks 3 months ago

    I love how computers run and work !! Have a deep interest in computers !!

  • Jonatan Søgaard
    Jonatan Søgaard 3 months ago +4

    Good and very informative video. I am way to young to have experienced the dawn of personal computers, but I of some reason, I just cannot stop wanting to learn more about old computers...

  • Russell Thompson
    Russell Thompson 3 months ago

    bIs there any truth to the oft told story that originally the PC was going to be a smart terminal replacing the 3278 et al terminals?

  • intel386DX
    intel386DX 3 months ago +1

    IBM used INTEL CPU,
    Apple used IBM CPU,
    Logic hahha

  • Phantom Phlier
    Phantom Phlier 3 months ago

    The IBM open architecture was the key to success.

  • Phantom Phlier
    Phantom Phlier 3 months ago

    Forgot Altar 8800

  • Sean Cunningham
    Sean Cunningham 4 months ago

    Something that seems to go by without any commentary is the model number. Yes, "5150" puts it in an established family but somehow I'm thinking, even though it's IBM, that it's more than coincidence that this is also the police code for "insane".

  • echopathy
    echopathy 4 months ago

    you're a great writer, man.

  • Nml45
    Nml45 4 months ago

    Excellent!!! Thank you, yea I was a user too.

  • Patti Brooks
    Patti Brooks 4 months ago

    I hear the IBM computers were the very first computers !

  • -p Catalano
    -p Catalano 4 months ago

    Glad you mentioned the PC jr. I had one of these as a kid and used it until about the mid 90s.

  • Ponk 80
    Ponk 80 4 months ago

    These iBeem devices were revolutionary, and changed the world for ever :)

  • Lancelot Xavier
    Lancelot Xavier 4 months ago +1

    I had one as a kid.
    Solid and great quality.
    But sooooooooooo slow.
    And Compuserve over dialup was also slow (and expensive).
    I felt it was not much more useful than a calculator.

  • Henry Pitts
    Henry Pitts 4 months ago

    Just for fun I bought a 5150 IBM styled case built for an Apple II mother board. Put in an Apple II+ clone board and 2 full size 5 1/4 floppy drives. I called it the Crab apple. I still have it in the attic somewhere. In the early 80's I would go to an event in Atlanta called the Hamfest. A huge flea market of electronics.

  • Michael Jordan
    Michael Jordan 4 months ago +3

    Memories... I was there for (almost) the whole ride - my first computer was a Mod I Level 2 TRS-80 with 4K of RAM. What IBM brought to the table was legitimacy. What had been a geek's toy, now became a legitimate business machine.

  • Francis Maxino
    Francis Maxino 5 months ago

    Hey, what about the ZX81 !

  • Francis Maxino
    Francis Maxino 5 months ago

    Pretty much a copy of an Apple II.

  • Orochii Zouveleki
    Orochii Zouveleki 5 months ago

    I'm kind of happy for IBM's mistakes, and even grateful for Microsoft existence (what would have happened if DOS was acquired by IBM?). I mean, all that pretty much contributed to the PC dominance and proliferation. If DOS wasn't available, there would had been another barrier for a standard. Or so I think.

  • laughingalien
    laughingalien 5 months ago

    Brilliant. Thank you, sir.

  • Ghost
    Ghost 5 months ago

  • Quaalude Charlie
    Quaalude Charlie 5 months ago +1

    Thank You , Great Content on the PC . Shared and a Thumbs Up :) QC

  • John Beaudette
    John Beaudette 5 months ago

    Is this the pc that works differently than all other PCs made before and after , that the supposed John titor came back n time for ? Lol Cheers

  • Dean Mires
    Dean Mires 5 months ago

    This is one of the most accurate and balanced PC computer history videos done.

  • Fit Fogey
    Fit Fogey 5 months ago +1

    Still the best form factor for a PC. IBM had it figured out at the beginning.

  • Computer History Archives Project

    Lots of great info, very well presented. Nice research too. Enjoyed this bit of microcomputer history. : )

  • David Kobza
    David Kobza 5 months ago


  • M L
    M L 6 months ago

    How time flies!

  • Pretoriano
    Pretoriano 6 months ago

    In that time the evolution was like light speed now we just have expensive and slow computer. We need a new revolution.

  • Harold McBroom
    Harold McBroom 6 months ago +1

    You forgot the AT&T 6300 640K ram, 1200 baud modem, dual floppies, CGA monitor
    That was a fantastic machine. I cried when that machine died. I had inherited it from my dad, and it gave me many, many years of service, without needed any maintenance.

    • Harold McBroom
      Harold McBroom 4 months ago

      +VideoTape Thanks, good to know... Regardless of who made it, it was a fine machine, well built, sturdy and reliable.

    • VideoTape
      VideoTape 4 months ago

      The real name of that machine is Olivetti M24 :) Italian engineering.

    • grant johnson
      grant johnson 4 months ago

      Harold McBroom if it broke then maybe it could have benefitted from some maintenance

  • kaczan3
    kaczan3 6 months ago

    From the earliest days, the computers were marketed to women, yet women complain gow this is a boys club and women are excluded.

  • Jason Bratcher
    Jason Bratcher 6 months ago

    Not to make it complicated, but to make is simple.
    Most software houses can't do that, especially if your software inadvertently gets used by:
    Someone with a visual/otherwise physical disability?

  • Jason Bratcher
    Jason Bratcher 6 months ago

    Model F keyboard.
    did you need some blunt-force weaponry?
    This beast can proudly deliver the necessary blunt force trauma you need; - in War... And Peace!