website/content/museum/ibm-pc-model-5150.md

---
title: IBM PC - Model 5150
categories:
- Computers
types:
- Professional Computer
origins:
- U.S.A.
years:
- '1981'
cpus:
- Intel 8088
params:
  name: PC - Model 5150
  image: /media/museum/photos/ibm_5150_system_s1.jpg
  company: /companies/ibm
  company_name: IBM
  specs:
  - label: NAME
    value: PC - Model 5150
  - label: MANUFACTURER
    value: IBM
  - label: TYPE
    value: Professional Computer
  - label: ORIGIN
    value: U.S.A.
  - label: YEAR
    value: '1981'
  - label: BUILT IN LANGUAGE
    value: IBM BASIC (Special Microsoft BASIC-80 version in ROM)
  - label: KEYBOARD
    value: Full stroke 'clicky' 83 keys with 10 function keys and numeric keypad
  - label: CPU
    value: Intel 8088
  - label: SPEED
    value: 4.77 MHz
  - label: CO-PROCESSOR
    value: Optional 8087 math coprocessor
  - label: RAM
    value: 64 KB (The very first ones had only 16 KB), 256 KB max. (then later 640 KB max.)
  - label: ROM
    value: 64 KB
  - label: TEXT MODES
    value: 40 or 80 char x 25 lines
  - label: GRAPHIC MODES
    value: 'Optional CGA graphic modes : 320 x 200 / 640 x 200'
  - label: COLORS
    value: Monochrome / 4 among 8 in 320 x 200 CGA mode
  - label: SOUND
    value: Tone Generator - built-in speaker
  - label: SIZE / WEIGHT
    value: 50.8 (W) x 40.6 (D) x 14 (H) cm
  - label: I/O PORTS
    value: Five internal 8 bit ISA slots, monitor, Centronics, cassette (!),
  - label: BUILT IN MEDIA
    value: One or two 160 KB 5.25'' disk-drives
  - label: OS
    value: MS-DOS, CP/M-86, USCD Pascal
  - label: POWER SUPPLY
    value: Built-in 63.5W switching power supply unit
  - label: PERIPHERALS
    value: 5 expansion slots, 5, 10, 20 MB hard discs
  - label: PRICE
    value: £1736 (1 FD, monochrome monitor, U.K., 1983)
  tabs:
  - photos
  - adverts
  - software
  - links
  photos:
  - title: INSIDE PC
    subtitle: ''
    text: |-
      A modular concept which allows user to add, remove or exchange any part of the computer.

      **(1)** Expansion slots for add-on cards. There are only five of these ones, which is almost too much for the 63 Watts power supply which cannot handle high power cards.\
      **(2)** Intel 8088 microprocessor. Next to it is an empty socket intended for an Intel 8087 math. coprocessor.\
      **(3)** The power supply is equiped with a security system which automatically cut the power in case of short-circuit or overheating.\
      **(4)** Floppy-disk controler card. The first PC was equiped with full height, single sided, single density, 160 Kb disk-drives.\
      **(5)** Disk eject levers.\
      **(6)** First PC motherboards included 64 Kb. RAM. Note that each row of memory circuits is composed of 9 chips, eight for memory plus one for parity control.\
      **(7)** ROMs holding the BIOS (Basic Input Output System) and the IBM Basic written by Microsoft.
    image: /media/museum/photos/ibm_5150_inside_1.jpg
  - title: PROMOTIONAL PICTURE
    subtitle: ''
    text: ''
    image: /media/museum/photos/ibm_pc5150_prm-pic_1.jpg
  adverts:
  - title: FIRST ADVERT - NOV.1981
    subtitle: ''
    text: Courtesy of **[Attached](http://www.aci.com.pl/mwichary/)**
    image: /media/museum/pubs/ibm_5150_pub81_s1.jpg
  - title: FIRST ADVERT - JAN.1982
    subtitle: ''
    text: Courtesy of **[Attached](http://www.aci.com.pl/mwichary/)**
    image: /media/museum/pubs/ibm_5150_pub81_s2.jpg
  - title: FIRST ADVERT - FEB.1982
    subtitle: ''
    text: Courtesy of **[Attached](http://www.aci.com.pl/mwichary/)**
    image: /media/museum/pubs/ibm_5150_pub81_s3.jpg
  - title: 'CHARLIE CHAPLIN #1'
    subtitle: ''
    text: |-
      1982 - Advert said:

      Stop in a store near you. Take a look. You'll be instantly taken with some of the features that make the IBM Personal Computer so different...
    image: /media/museum/pubs/ibm_5150_pub_1.jpg
  - title: 'CHARLIE CHAPLIN #2'
    subtitle: ''
    text: |-
      1982 - It was the time when one still lacked good programs for the IBM PC...

      Advert said:

      Attention, all programmers. Here's a chance to reach the top.\
      If you've written software that's completed and runs on the IBM Personal Computer (or another computer), we could be interested in publishing it...\
      ... We select programs that will make the IBM Personal Computer an even more useful toll for modern times...
    image: /media/museum/pubs/ibm_5150_chaplinpub_2.jpg
  - title: 'CHARLIE CHAPLIN #3'
    subtitle: ''
    text: |-
      1983 - Before the IBM PC became THE universal standard, IBM was looking for good programs using all the features IBM Basic could offer.

      Advert said:

      Let your imagination take wing.\
      Think charts, Graphs, Shapes, Images.\
      Use originality, creativity and color in programs that entertain, educate, organize, analyse. And programs that get down to business...\
      ...In fact, if you are interested in licensing your software, we could be interested in publishing it...
    image: /media/museum/pubs/ibm_5150_chaplinpub_3.jpg
  - title: 'CHARLIE CHAPLIN #4'
    subtitle: ''
    text: |-
      In June 1983, IBM was still seeking independant programmers.\
      Advert said:

      There's an acceptance letter inside. And a check that could have your name on it. (If we select your program, that is.)\
      But remember. We pick our winners carefully...
    image: /media/museum/pubs/ibm_5150_chaplinpub_4.jpg
  - title: 'CHARLIE CHAPLIN #5'
    subtitle: ''
    text: Courtesy of **[Attached](http://www.aci.com.pl/mwichary/)**
    image: /media/museum/pubs/ibm_5150_chaplinpub_5.jpg
  - title: 'CHARLIE CHAPLIN #6'
    subtitle: ''
    text: |-
      From Personal Computing, July 1982 issue.

      Courtesy of **[Attached](http://www.aci.com.pl/mwichary/)**
    image: /media/museum/pubs/ibm_5150_chaplinpub_6.jpg
  - title: 'CHARLIE CHAPLIN #7'
    subtitle: ''
    text: |-
      TopView, one of the first serious multitasking tool for the IBM PC.

      Byte Magazine, July 1985
    image: /media/museum/pubs/ibm_5150_chaplinpub_7.jpg
  - title: US ADVERT (APRIL 1982)
    subtitle: ''
    text: ''
    image: null
  - title: FRENCH AD (DEC.1983)
    subtitle: ''
    text: '"Simplify your everyday life"'
    image: /media/museum/pubs/ibm_pc5150_pub_simplifiez-quotidien.jpg
  screenshots:
  - title: WRITING ASSISTANT
    subtitle: ''
    text: |-
      This word processor was a part of the 'Assistant' pack IBM offered. It was composed of:\
      \- Writing Assistant (word processor)\
      \- Filing Assistant (Database)\
      \- Reporting Assistant (Database reports)\
      \- Graphing Assistant (Graphic Charts)
    image: /media/museum/software/ibm_5150_writingassist_1.jpg
  links:
  - title: Vintage IBM
    url: http://www.vintageibm.net
    text: site is dedicated to the preservation and restoration of the IBM 5150 line of computers
  comments:
  - 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: Rogelio (México)
    date: Saturday 9th November 2013
    text: |-
      Hey, I´m into a project.\
      Looking for an old IBM 515O STYLED PC AND SCREEN.\
      Don´t need to be working, just need the enclosures: PC and the screen ones.\
      (The PC elcossures should have the floppy readers)
  - author: Willem Weijgertse (The Netherlands)
    date: Friday 13rd July 2012
    text: |-
      I have two pc''s of the model, with monochrome monitors but no original keyboards.\
      One with two 5,25 inch drives, 512kb Ram.\
      And one with a 10 Mb harddisk en a 5,25 inch drive.
  - author: Teun Raaijmakers (Netherlands)
    date: Wednesday 24th August 2011
    text: |-
      i found al lot of 5,25inch drives for this model IBM.\
      so if someone is looking for 1 or 100 i have them.\
      teun1984 (a) hotmail . com
  - author: Laura (USA)
    date: Tuesday 12th July 2011
    text: |-
      I''ve listed some old Sligh office furniture catalogs on Etsy, which have a photo of what I believe is this same computer. Can anyone confirm?

      Here''s the link to the listing. http://www.etsy.com/shop/lauraslastditch
  - author: PROCOMP_ARG (ARGENTINA)
    date: Thursday 12th May 2011
    text: |-
      This was my first PC repaired by my hands and with only basic aknowledge in electronics.\
      The 5150 was set at our Library and an memory error mesage appeared when you powered on.\
      It had a bad memory chip and I didn´t know how to fix it.\
      So I found the solution in Brenner´s book which deserve my respects at all.
  - author: Thom Anderson (USA)
    date: Saturday 18th September 2010
    text: |-
      "Jeffrey H. Ingber" is remembering history wrong. I built literally thousands of machines when working for resellers in the Los Angeles area. You could order a PC with no drives, one drive, or two drives. The XT came out of the box with a 5 1/4" drive and a 10mb hard drive. You could order them that way right out of the box, and take them home.

      Now, what alot of operations did was customize. Pull out the single drives and stack two 1/2 height floppy drives. Order the XT with no hard drive and put in a 20 or 40mb hard drive with its own controller.

      The idea that you "couldn''t" go in and get from IBM a machine ready to run out of the box is hogwash. People did it all day, every day. The biggest sellers for home use were two drive PCs from the factory, and standard XTs with the hard drive from the factory. Hughes Aircraft, Rockwell and others would order XTs without the hard drive and have third party Seagates put into them$by the THOUSANDS. Our config center would crank out hundreds of machines over a weekend, so I know what I am talking about!
  - author: Raindance Rob (UK)
    date: Saturday 31st July 2010
    text: my old man brought one of these from work back in about 93-94 for £50 i had it in my room $ spent much of my childhood using one for word processing $ playing games. in order to play a game or load a floppy you had to enter a command as they wouldnt just run otherwise. our one had on floppy drive $ i wasnt much for the screen as it would get whatever you had been doing burned onto the screen, plus it used to give me headaches which no other monitor has ever given me lol i owe alot to these PC''s as they started my interest in computers which i still have today $ has been a lifelong hobby. unfortunately when we moved house it got left behind in our old house $ i do miss it alot, i would definitely buy another one
  - author: Alessio Di Domizio
    date: Sunday 8th November 2009
    text: |-
      I''ve done some extensive research about the MS/DRI debate. As Tom Rolander (DRI) states in many interviews, DRI was indeed interested in having their OS in the IBM PC. Gary Kildall and Rolander did meet IBM executives, there were some early licensing disputes (it seems that IBM wanted to buy the whole CP/M 86, while DRI obviously preferred a licensing scheme). IBM then involved Microsoft to have an OS ready for the PC launch.

      Microsoft proceeded with buying QDOS from Tim Paterson - who wrote it in 6 weeks QDOS - many suspect it to be a CP/M ripoff.

      After some legal threats from DRI against IBM, both a completely rewritten MS'' QDOS (due to bugs, IBM had to rewrite it fron scratch), branded PC-DOS, and CP/M were given as an option to PC buyers.

      As DRI''s Rolander recalls, when the IBM PC went on sale, CP/M option was priced $ 240, while Microsoft-IBM PC-DOS was priced $ 40.
  - author: Bob Teodori (USA)
    date: Tuesday 19th May 2009
    text: |-
      I had one of these old beasts. I had the Hercules Graphics card and an Amdek amber-on-black monochrome monitor. It did indeed have the 8-bit slots but there were only 6 of them. The XT had 8. Most of the chipsets on the board were made by texas instruments although I do also remember seeing hitachi and samsung chips as well. I remember this because when I was 12, I took the thing apart right down to the screws and rebuilt it again. This computer is the reason I know how to build PCs today. (Like my Phenom II system I just built last week! LOL!) The upgradability was fantastic for its day and at the very end, I had an AdLib sound card and an ATi EGA Wonder. Ahhh, the carefree days of my youth. I actually even ran my BBS on it with a 2400bps modem for over a year. \*grin\* my BBS, Seventh Heaven can currently be found on the historic area code 416 BBS List.\
      Oh yeah, one more thing. It took a full 2 minutes for the thing to boot once you managed to get your hand to the back of the case to flip the power switch.
  - author: David E Wyant is not completely correct
    date: Saturday 4th April 2009
    text: Bill Gates didn''t have an OS so he SENT Jack Sams to see Gary Kildall about CP/M. When Gary''s wife Dorothy turned them away, Bill realized that he needed to get an OS or his deal with IBM might fall apart.
  - author: David E Wyant (USA)
    date: Saturday 4th April 2009
    text: The reason IBM did not go with CP/M is that two guys in IBM garb showed up at the CP/M location in Sunnyvale (which was a home) to discuss that IBM was going to build a PC. The husband wasn''t home and, before they would even tell the wife who they were, they asked the wife to sign a 22 page disclosure (standard for IBM when working with other OEMs). She was so overwhelmed and confused that she threw them out. They then called back to their manager who suggested that, since they were already on the west coast, they go up to talk to "that guy who wrote the basic".
  - author: T Heavey (Olympia, WA)
    date: Saturday 12th August 2006
    text: |-
      In 1983 we were a new government program and my boss, a great visionary - who none-the-less considered a pencil to be a portable printer, my boss knew this "PC Thingy" would be important. Because I had been playing around at home with TRS-99 he appointed me to be "the computer guy."

      We purchased an IBM PC with an 8086 chip. It was the second PC in the entire State Employment Agency. Two floppy drives and one 10 megabyte hard drive in the expansion chasis. (During design phase I requested a 20 megabyte hard and I was told by our "expert" - '10 megabytes is more than you will use in a life time.')\
      I later added a second 10 megabyte hard drive in the expansion chasis. dBase II was the main piece of software I ran, with some word processing with WordStar.\
      By using the PC to organize data collection we were able to demonstrate the effectiveness of our programs and we continue to serve the people 23 years later.\
      I have retired now, but thousands and thousands of young people owe a great start in their working life to vision of that one guy and the use of the IBM PC.
  - author: Jonathan Hubbard (Utah)
    date: Friday 28th July 2006
    text: I own one of these computers it has never been used and is like in prestine shape does anyone know how much I could sell it for.
  - author: SirOrlando (Utah (USA))
    date: Tuesday 25th April 2006
    text: |-
      To John Cowley:

      This reply comes a year later, but regarding "Non-System Disk or Disk Error," the answer is quite simple:

      In order to boot up properly, an operating system is required. As these computer systems only came with floppy drives (originally), you must start the computer with a "Boot Disk" in the first of the two floppy drives.

      Assuming the disk has the necessary system files on it, and it has not become corrupt, then they will allow the operating system to load into memory. If successful, you will come up with a DOS command prompt.

      During a time before the success of the mouse, the IBM PC and compatible computers ran completely from a command prompt. From here, you can swap diskettes, enter commands, and launch programs. But without a "System Disk," to tell the machine how to talk to it's hardware and peripherals, the computer is unusable.
  - author: Rick (Sussex, United Kingdom)
    date: Thursday 13rd April 2006
    text: 'Back in the early nineties I bought one of these second hand and wrote my entire four years'' worth on university work on it! Mine had a hardcard - a 30MB HDD on an expansion card - in it, which made things a lot easier. Those were the days: DOS and WordPerfect 5.1 !!!'
  - author: Renzin (USA)
    date: Wednesday 3rd August 2005
    text: My dad used to use these at his job. The drives were so primitive, so they liked to eat disks. Can you attatch a 3.5 floppy on this?
  - author: john cowley (virginia)
    date: Saturday 12th February 2005
    text: |-
      i was working with the 5150 personal computer, and every time I try to start it up it says: "Non-System or system disk error, press any key when ready."\
      Do any of you'll know whats wrong w/ it and how to fix it?
  - author: javier (canary islands)
    date: Thursday 15th July 2004
    text: this computer was the origin of the wold´s most succesfull computer architecture
  - author: Matjaz (Ljubljana)
    date: Monday 26th April 2004
    text: To Maja - IBM-PC is copyrighted, but it is very hard to prevent somebody to do some reverse-engineering and build a 100% compatible machine from scratch. In IBM's case, that was Compaq, I belive. IBM even sued them over copyright infringment of the BIOS code, but they lost, as we can all see. And rightfully so - reverse-engineering is not the same as copying and if done in the spirit of "fair use" - perfectly legal.
  - author: Maja (Ljubljana,Slovenia)
    date: Saturday 10th May 2003
    text: |-
      Hi. Does anyone happen to know, why IBM did not patent the original PC? I mean, how did it happen that everybodey started cloning the thing. Was that IBM's intent or did it happen by accident?\
      If anyone knows,I'd much appreciate the info.\
      Tnx.\
      M
  - author: Yves Mc Donald (Montreal, Canada)
    date: Saturday 7th September 2002
    text: |-
      Microsoft Flight Simulator 2 was the best hardware compatibility test software to evaluate IBM PC clones!\
      The PC keyboard had an excellent feei but was VERY noisy and CGA output in text mode was flickering when scrolling text. MDA display was eye-pleasing and character generator supported accented letters; great tought for non-English users!
  - author: Newtony (Belgium)
    date: Tuesday 12th February 2002
    text: |-
      Hi Jiri,\
      try the two links below, they have tons of old games !

      http://www.dosgamesarchive.com/download/list.php\
      http://www.theunderdogs.org/
  - author: Jiri (British Columbia, Canada)
    date: Wednesday 30th January 2002
    text: Anyone know where I might be able to find some interesting software for my IBM-PC 5150. I have DOS 3.1 and 3.3 disks but am looking for old programs and games etc. Thanks...
  related:
  - /museum/amstrad-pc-1512
  - /museum/amstrad-pc-1640
  - /museum/amstrad-ppc-512-640
  - /museum/ibm-pc-at
  - /museum/ibm-pc-portable-model-5155
  - /museum/ibm-pc-xt-286
  - /museum/ibm-pc-xt-model-5160
  - /museum/ibm-ps-1
  - /museum/micronique-hector-xt
  oc_id: 274
  source:
    url: https://web.archive.org/web/20230606185231/http://www.old-computers.com/museum/computer.asp?c=274
    date: '2023-06-06'
---

The computer which caused the death of CP/M computers.

In the early part of 1980, IBM decided to create a microcomputer (up to this date, IBM produced only mini and mainframes). They didn't really know that they wanted and they didn't think for one second that producing microcomputer was a profitable business (who would have thought!)!\
After hesitation between the Intel 8086 (16 bit) and the Motorola MC68000, they decided to use the Intel 8088 (8 - 16 bit) processor, as the two other ones were considered too powerful! Then they asked to Digital Research (the creators of CP/M) to create an operating system for their new computer, as DR was not very interested, they then asked a small company (famous for its BASIC Programming Language) to write the operating system: Microsoft.\
Microsoft wasn't capable of doing it, Bill Gates bought the rights to a small, hacked OS written by a small company called [Seattle Computer Products](/museum/seattle-computer-gazelle/): QDOS (which reportedly stood for "Quick and Dirty Operating System", which itself bears a striking resemblance to CP/M) which became PC-DOS and then later MS-DOS!\
In fact, when it was launched, three operating systems could run on the IBM-PC: PC-DOS, CPM-86, but also the UCSD D-PASCAL system.

The original IBM PC wasn't very powerful (and was certainly less powerful than lot of 8 bit computers at the time). The very first PC’s had only 16 KB RAM and no floppy disk units, they used cassettes to load & store programs (notice that the commands to handle the cassette drives were present in the operating system all the way up to MS-DOS 5!). In fact, units could also be purchased from IBM with drives and more RAM. Only the lowest cost version had no drives included (this is exactly how Apple and the other manufacturers did it as well).

The model 5150 was actually a success due to name and fame of IBM, high quality construction (especially the keyboard and monitor), great expandability and IBM's decision to publish complete technical specs. The IBM PC Technical manual included circuit diagrams and the full source code for the BIOS! The PC 5150 became a standard and IBM ran the business computer market up to the end of the 80's.

Now, we can consider that about 90% of the microcomputers are PC compatibles and run under MS-DOS or Windows (At the beginning, Windows was just a graphic interface for MS-DOS, but that’s another story).

Although the [IBM PC XT](/museum/ibm-pc-xt-model-5160/) was launched in 1983, IBM continued production of both units, in various configurations, for several years. The model types were followed by a xx version number, i.e. 5150-xx, where the xx represented the included options (amount of RAM, single or dual floppy disk drive, etc.).

Jeffrey H. Ingber reports that when these computers (PC and XT) were initially sold, they were built-to-order computers (sounds like Gateway or Dell, doesn’t it?). Retail outlets would carry the factory products, which consisted of a boxed computer with basic components such as the motherboard, power supply, floppies & floppy drives, etc. There was no official base model configurations for the PC and XT.\
Customers had a choice of RAM, display, serial ports, etc. that they could have installed on-site before the computer went home.\
One could not purchase a "new" PC/XT and run it out of the box becuase it was incomplete without additional configuration.

The PC was available with either CGA or MDA (on an MPA card). The CGA adapter actually has an RCA composite output to hook it up to your TV if you did not want the CGA monitor. The output quality was PERFECT!

Another notable great feature of the PC line was the expansion base: it added additional (I think it was eight) 8-bit slots in an external enclosure.