The IBM Personal Computer

The year is 1977. Apple Computer, a newly-formed company founded by Steve Jobs and Steve “Woz” Wozniak, is selling their Apple II computer. Meanwhile, other companies – such as Commodore and Texas Instruments – join the young Apple Computer to get a slice of the microcomputer market. Microcomputer Mania! is in full swing.

Meanwhile, IBM – a company who dominated the computer market thanks to their mainframe and miniframe systems (such as the 1401, System/360, System/370, 1130, and System/3x) – was loosing significant market share to small companies and their microcomputers. Microcomputers were marketed to small businesses and home use, allowing home users to own their own computer.

IBM’s earliest attempts at releasing a microcomputer – such as the 5100 and 5120 (released in 1975 and 1980, respectively) – were not successful. So, as they say, the third time is the charm.

In 1981, IBM released the Personal Computer – or PC. The PC started an industry standard, retained IBM’s position as a household name, and more.

Releasing the PC

IBM assembled a small team of engineers to work on the PC in Boca Raton, Florida. The team, lead by Don Estridge, hunkered down in their work space (the “Skunkworks”) to produce the PC from pre-made components.

Making a computer from off-the-shelf componentry wasn’t like IBM, a company who basically made everything from scratch before. The company had to use off-the-shelf components in order to release a machine quick enough to compete with other companies that were quickly developing new equipment. IBM had also reduced the bureaucracy and red tape. Instead of taking the “nine months to ship an empty box”, IBM released the PC almost as soon as it was complete.

Public Reactions to the PC

The PC was released with some fanfare and some disgust.

On one hand, people in the microcomputer hobby and industry already were angry. A giant corporation like IBM had stepped into their territory, which was dominated by people under the age of 30 and relatively small, new companies.

However, people in the business community were excited. As the saying went: “nobody ever got fired for buying an IBM.” IBM was a large company with a long history to back themselves up, offering support on their own equipment. Therefore, businesses no longer felt the uncertainty that came with doing business with small companies.

Under the Hood

As previously mentioned, IBM used off-the-shelf components in the making of the Personal Computer. Everything, from the processor to the operating system, was off-the-shelf.

The brains of the PC was an Intel 8088 clocked at 4.77 MHz. The original model (5150) was offered with anywhere between 16kb and 64kb of memory. The 5150 didn’t include or have the option for a hard disk drive; instead, it had two 5.25″ floppy disk drives.

Video display of the original 5150 was monochromatic through a “MDA” video card. The IBM 5151 monitor was the infamous “green screen” CRT monitor which often accompanied the IBM PC. (The green color is from the phosphor used in the screen.) The IBM PC (5150) could be upgraded to use the 5153 color CRT monitor, which used the CGA video card.

Marketing the PC

Charlie Chaplin’s “The Little Tramp” was used to market the IBM PC and “give it a face.”

IBM decided to use Charlie Chaplin’s “Little Tramp”, a silent-film era star, in the advertisements for the IBM PC line. Chaplin was played by Billy Scudder, and, according to Time Magazine, gave the PC “a face.” Others used Chaplin, with his trademark bowler hat and cane to represent or even satirize the company. The use of Chaplin was somewhat ironic, given that Chaplin (with his “Little Tramp” character) starred in Modern Times, a movie which expressed the star’s opposition to big business and technological efficiency, whereas the PC was produced by one of the world’s largest companies. The “Little Tramp” became a “warm cuddly” – according to Creative Computing – mascot for IBM and the PC line, much like how Tux the penguin became a mascot for Linux-based operating systems, and how Clippy, the paperclip which was found as an assistant in Microsoft Office 97-2003), was a mascot for the Microsoft Office suite.


By 1983, the IBM PC enjoyed much success. In March 1983, the first update to the original 5150 PC had been released. The PC-XT (Xtended Technology) came standard with 128kb of memory – which is the same amount that the original Macintosh shipped with nearly a year later. The PC-XT also came with a 10MB Seagate hard drive, a 5.25″ floppy drive, and the same Intel 8088 clocked at 4.77MHz.

Over one year later, another update was released. The PC-AT (Advanced Technology) featured an entire overhaul. The PC-AT featured the Intel 80286 clocked at 6 MHz and standard 256kb of memory (although it could be configured up to 16MB.) The AT also originally featured 2 5.25″ floppy drives, and a 20MB hard drive. (Although a 30MB hard drive was sold in 1986.)  The AT also featured a real-time clock chip with battery backup.


While IBM’s PC family was successful, it wasn’t immune to failures.

The PCjr, released in March 1984, was created in an effort to bring the PC into the home. Manufactured for IBM by Teledyne in Lewisburg, Tennessee, the machine featured an Intel 8088 clocked at 4.77MHz, 64kb of memory, one 5.25″ floppy drive, and no floppy drive. The PCjr could easily be expanded through the use of “sidecars.” Another feature of the PCjr was the use of a wireless chicklet keyboard, known as the “Freeboard.”

In an essence, the PCjr was a total flop. (Click here to read more about the PCjr.)

PC Convertible

Two “portable” PCs were released: the Portable PC, and the PC Convertible.

The IBM Portable was a luggable, released in February 1984 as a response to the Compaq Portable. Tipping the scales at 30 pounds, the machine resembles a sewing machine more than a computer.

The second machine, the PC Convertible, was IBM’s first attempt at creating a truly portable PC. The PC Convertible weighed a respectful 13 pounds (light compared to the luggables of the time), and used the Intel 80c88 processor – clocked at the usual 4.77MHz. The PC Convertible used a LCD monochromatic display and featured 256kb of memory. The machine had no hard drive; rather, it used two 3.5″ floppy disk drives. (The PC Convertible featured two firsts in the IBM line of personal computers: the use of 3.5″ floppy drives, and it could run on battery power.)

Unfortunately, the PC Convertible was released very late in the PC family’s lifespan. The PC Convertible was released in April 1986. One year later, in April 1987, the PS/2 family was released.

The Clones are Here!

The IBM PC created an industry standard. The basic structure for modern PCs – from the name to the way they work – was a result of the IBM PC.

However, since the original PC was made using off-the-shelf components, it was fairly easily to “clone.” The operating system, MS-DOS, was readily available to clones. The only thing that needed to be made was the BIOS (Basic Input/Output System) – which was replicated by companies such as Phoenix, Award Software, and American Megatrends.

The PC cloning industry gave rise to many companies producing “IBM PC-clones” or “PC-compatibles”. Out of the PC cloning industry came Compaq (one of the earliest clones making luggables), PCs-Limited (later Dell), and others. Some of IBM’s competitors from the mainframe days joined in – such as Hewlett-Packard, DEC, and NCR.

This, over time, would prove to be a large problem for IBM. In April 1987, the Personal System/2 (PS/2) family officially replaced the PC family in an effort to regain some of IBM’s lost market share.


These are the specifications which were standard; they do not include add-ons and expansions which could be done by the owner.

IBM PC (5150) – August 1981

Processor (with clock speed) Intel 8088 (clocked @ 4.77 MHz
Standard RAM 16kb – 64kb
Floppy Disk Drives 2 (5.25″ floppy diskette drives)
Hard Disk Drives 0 (standard)
Display Output CGA / MDA Monochromatic (used with display #5151 or #5153, color)
Other unique features Cassette tape port on rear
Cost (1981 – 2016 with inflation)*
[cheapest configuration: 0 floppy diskette drives, 16kb RAM, no monitor]
$1,565 ($4,143.15 in 2016)

IBM PC-XT (5160) – March 1983

Processor (with clock speed) Intel 8088 (clocked @ 4.77 MHz)
Standard RAM 128kb
Floppy Disk Drives 1 (5.25″ floppy diskette drive)
Hard Disk Drive 1 (10 MB Seagate ST-412 MFM)
Display Output MDA Monochromatic, CGA, EGA, PGC
Other unique features 130-watt power supply, socket for optional 8087 math coprocessor/FPU
Cost (1983 – 2016 with inflation)* ???

IBM PCjr (4860) – March 1984

Processor (with clock speed) Intel 8088 (clocked @ 4.77 MHz)
Standard RAM 64kb
Floppy Disk Drives 1 (5.25″ floppy diskette drive)
Hard Disk Drive 0
Display Output Video Gate Array/Tandy Graphics Adapter (TGA) – not modern Video Graphics Array (VGA)
Other unique features Wireless chiclet-style keyboard “Freeboard”; manufactured by Teledyne in Lewisburg, TN for IBM
Cost (1984 – 2016 with inflation)*
[cheapest config.: 64kb RAM]
$669 ($1,549.50 in 2016)

IBM PC-AT (5170) – August 1984

Processor (with clock speed) Intel 80286 @ 6 MHz
Standard RAM 256kb – 16 MB
Floppy Disk Drives 2 (5.25″ floppy diskette drive)
Hard Disk Drives 1 (20 MB)
(30 MB model introduced in 1986)
Display Output CGA, MDA, EGA, PGA
Other unique features Real-time clock with battery backup
Price (1984 – 2016 with inflation)
$6000 ($13,896.84 in 2016 with inflation)

IBM PC Convertible – April 1986

Processor (with clock speed) Intel 80c88 (CMOS version of 8088) @ 4.77 MHz
Standard RAM 256kb – 640kb
Floppy Disk Drives 2 (3.5″ floppy diskette drives – first computer by IBM to use 3.5″ floppy disk drives)
Hard Disk Drives 0
Display Output Built-in monochromatic LCD
Other unique features Featured a “docking station” with a full-size monitor, to overcome the horrible (nearly unreadable) LCD screen built into the computer. Replaced by the PS/2 L40 SX (laptop) in 1989.
Price (1986 – 2016 with inflation) $2,000 ($4,391.37 in 2016, with inflation)

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