IBM PC 5150: Everything You Need To Know

Three Facts About IBM PC 5150

• The IBM PC 5150 originally cost less than $1,600, which was far less than the $9 million price tag of older computers.
• Despite the term “Personal Computer,” the IBM PC 5150 was designed primarily for business use.
• This IBM PC was introduced as part of the 5000 microcomputer series, but its architecture was significantly different from the IBM 5100.

The History of IBM PC 5150: What To Know

The biggest computer manufacturer in the world — IBM, was in a difficult situation in the 1970s. Despite IBM’s multimillion efforts to get into the small computer market, the market was dominated by the Commodore PET, Atari 8-bit family, Apple II, and Tandy Corporation’s TRS-80, as well as various CP/M machines.

The IBM PC was created in about a year by a team of 12 IBM engineers and designers under the direction of Don Estridge of the IBM Entry Systems Division in Boca Raton, Florida. After hesitation between the Intel 8086 and the Motorola MC68000 (16 bit CPUs), they decided to use the Intel 8088 (8/16 bit) processor.

Then they asked Digital Research (the creators of CP/M) to create an operating system for their new computer. Digital Research declined, so IBM asked a small company (known for its BASIC Programming Language, first used in Altair 8800) to write the operating system: Microsoft.

IBM PC 5150 Versions: Each Edition

IBM chose the name 5150 for this successful personal computer, which referred to the 5100 series of IBM computers. These two versions were the only computers introduced in this series.

IBM 5100

IBM’s first desktop microcomputer, the IBM 5100, was introduced in 1975. It was a complete system with a built-in monitor, keyboard, and data storage. Unfortunately, it was very expensive—up to $20,000, so it didn’t achieve market success.

IBM 5150

Far more affordable, portable, and practical, the IBM 5150 became a commercial success. It sold far more than the IBM 5100, being more convenient for home use. The IBM PC 5150 microcomputer included the following specs:

• Starting at 64 KB RAM
• Intel 8008 CPU
• Full-stroke, 83-key keyboard
• Monochrome display
• Five internal I/O ports
• One or two 160 KB, 5.25-inch disk drives
• Three OS options: MS-DOS, CP/M-86, and USCD Pascal

IBM PC XT

Although the IBM PC XT was launched in 1983. This version was an improvement on the PC 5150 design. It was the first IBM PC to come with an internal hard drive as standard.

IBM AT

IBM AT was launched in 1984. It used the new Intel 80286 CPU and other improved specs. IBM continued production of the original PC in various configurations for several years. The model types were followed by an xx version number, i.e. 5150-xx, where the xx represented the included options, such as the amount of RAM and single or dual floppy disk drive.

IBM PC 5150: Historical Significance

IBM PC 5150 became a commercial success due to the 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. While the original IBM PC technology is largely obsolete by today’s standards, many are still in service.

Factors that have contributed to the 5150 PC’s longevity are its flexible modular design and open technical standard making information needed to adapt, modify, and repair the microcomputer readily available. It also didn’t use many special, nonstandard parts and came with a rugged IBM design.

This provided for exceptional long-term reliability and durability. Most newer PCs, by contrast, use special-purpose chips (ASICs) implementing trend-driven technology, which becomes obsolete in a few years typically after the parts become unavailable.

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