IBM 5150 (Original PC)
[vin29]
The IBM 5150, introduced on August 12, 1981, was IBM’s first microcomputer and the machine that defined the modern personal computer standard. Built around the Intel 8088 processor running at 4.77 MHz, the 5150 combined a 16-bit internal architecture with an 8-bit external data bus, helping keep costs down while delivering strong performance for its time. It featured five ISA expansion slots, support for 16 KB to 256 KB of RAM (expandable to 640 KB), and options for cassette storage or one to two 5.25-inch floppy drives. Users could choose between monochrome or color graphics adapters, making the system adaptable for both business productivity and home applications.
A defining characteristic of the 5150 was its open architecture and reliance on off-the-shelf components. IBM published extensive technical documentation, which allowed third-party developers to create compatible hardware and software, from expansion cards to complete clone systems. The machine ran PC DOS, developed by Microsoft, establishing DOS as the dominant operating system platform for years to come. Its BIOS was eventually reverse-engineered, accelerating the rise of IBM-compatible computers throughout the 1980’s.
The 5150’s impact was immediate and profound. IBM sold 65,000 units within its first four months and had taken 100,000 orders by Christmas 1981, extraordinary numbers for the young microcomputer industry. More than just a successful product, the IBM PC 5150 launched the “PC revolution” creating the IBM-compatible standard that would dominate personal and business computing for decades and shaping the trajectory of the entire computer industry.
- Manufacturer: International Business Machines (IBM)
- Type: Desktop Personal Computer (PC)
- Release Date: August 1981
- Cost at release: USD $1,565 (CAD ~$6,100 adjusted for inflation)
- Cost with peripherals: USD $6,000 (CAD ~$23,500 adjusted for inflation)
- MIPS: 0.33 (330 KIPS)
- Hardware Specifications
-
- CPU: Intel 8088 @ 4.77 MHz (16-bit internal, 8-bit external bus)
- Memory: 16 KB (base) to 256 KB on motherboard; expandable to 640 KB with add-on cards
- Expansion: 5 ISA (Industry Standard Architecture) slots
- Storage: One or two 5.25″ floppy drives (160 KB or 320 KB each); cassette tape interface (rarely used)
- Graphics: Choice of Monochrome Display Adapter (MDA) or Color Graphics Adapter (CGA), MDA: 80×25 text only, CGA: Up to 320×200 in 4 colors, or 640×200 in monochrome
- Sound: Simple internal speaker (single programmable-frequency square wave)
- Keyboard: 83-key Model F keyboard
- Ports: Parallel, serial, cassette, expansion slots
- Power Supply: 63.5W internal
- Physical: 24–30 lb (11–14 kg); two full-height drive bays
- Operating System & Programming Languages
-
Operating System: IBM PC DOS (developed by Microsoft, later known as MS-DOS), but also supported CP/M-86 and the UCSD p-System
-
Supported Languages: Languages available included IBM BASIC (in ROM and disk versions), Microsoft BASIC, Pascal, FORTRAN, COBOL, and C, among others
- Notables
- IBM’s first microcomputer and set the standard for personal computing with its open architecture and published technical specifications enabled a booming market for third-party hardware and software, spawning the entire IBM-compatible PC industry.
- The IBM PC was developed in just one year, an incredibly short time for IBM which was known for taking years to create new products.
- It was unveiled on August 12, 1981, at the Waldorf Hotel in New York.
- The project to create the PC was codenamed “Project Chess”.
- The system’s massive popularity and influence led to the term “PC” becoming synonymous with personal computers in general, and its architecture remains foundational for modern PCs.
- IBM’s advertising campaign featured Charlie Chaplin’s “Little Tramp” character, making the PC a cultural icon.
- The 5150 was not the first personal computer, but it was the first to achieve mainstream business and consumer adoption, outpacing competitors like Apple, Commodore, and Atari.
- The original IBM PC keyboard is still renowned for its tactile quality and durability.
- The model number “5150” has no special meaning beyond IBM’s internal numbering scheme.
- Many IBM PCs remained in use for decades, including in specialized roles such as weather data processing by the U.S. National Weather Service.
- It created the standards that dominated personal computing for the next 40 years
- The open architecture led to a booming market of IBM PC-compatible computers
- “Colossal Cave Adventure” was the first video game available for the IBM PC
- Some original IBM PCs from 1981 still function today, over 40 years later, due to their modular design and high-quality manufacturing
Video
Share: Twitter, Facebook
Short URL:
https://carleton.ca/scs/?p=20285
The IBM 5150, introduced on August 12, 1981, was IBM’s first microcomputer and the machine that defined the modern personal computer standard. Built around the Intel 8088 processor running at 4.77 MHz, the 5150 combined a 16-bit internal architecture with an 8-bit external data bus, helping keep costs down while delivering strong performance for its time. It featured five ISA expansion slots, support for 16 KB to 256 KB of RAM (expandable to 640 KB), and options for cassette storage or one to two 5.25-inch floppy drives. Users could choose between monochrome or color graphics adapters, making the system adaptable for both business productivity and home applications.
