Altair 8800

Altair 8800
source
Name	Altair 8800
Caption	An Altair 8800 computer with front panel visible.
Manufacturer	MITS
Designer	Ed Roberts
Type	Microcomputer
Release date	January 1975
Price	US$439 (kit), US$621 (assembled)
Cpu	Intel 8080
Memory	256 bytes (standard), expandable to 64 KB
Storage	Paper tape
Display	Front panel LEDs and switches
Input	Front panel switches
Os	Altair BASIC

Altair 8800. The Altair 8800 is a microcomputer designed by MITS based on the Intel 8080 microprocessor. Its January 1975 release, notably featured on the cover of Popular Electronics, is widely considered the catalyst that sparked the microcomputer revolution. The machine's kit form, affordable price, and open architecture inspired a generation of hobbyists, including the founders of Microsoft, and established the S-100 bus as an early industry standard.

History and development

The Altair 8800 was conceived by Ed Roberts, founder of MITS, a company previously known for calculator kits. Facing financial difficulties, Roberts bet the company on creating an affordable computer kit for hobbyists, selecting the newly released Intel 8080 as its central processing unit. The design was finalized by Roberts and William Yates, with the name reportedly chosen by the daughter of a Popular Electronics editor after the star Altair. The landmark article in the January 1975 issue of Popular Electronics, authored by technical editor Les Solomon, presented the machine as a project anyone could build, creating unprecedented demand. Initial production struggled to meet orders, famously leading to shipping delays and quality control issues, but the fervor it generated was undeniable.

Technical specifications

At its core, the system utilized an Intel 8080 microprocessor running at 2 MHz. Standard memory was a mere 256 bytes of static RAM, expandable via the proprietary backplane to 64 KB. The defining feature of its architecture was the 100-pin S-100 bus, which became a *de facto* standard for early microcomputers. Input and output were primarily accomplished through a front panel of toggle switches and LED indicator lights, with no built-in keyboard, monitor, or storage. Data and programs were loaded and saved using an optional paper tape reader connected via a serial interface. The power supply was a substantial component, and the entire system was housed in a distinctive blue metal case.

Impact and legacy

The release of this machine is credited with launching the personal computer industry. It demonstrated a viable market for microcomputers, inspiring the creation of numerous computer clubs, most famously the Homebrew Computer Club in Silicon Valley. The coverage in Popular Electronics directly motivated individuals like Steve Wozniak to design what would become the Apple I, and it provided the first major business opportunity for Paul Allen and Bill Gates, who founded Microsoft to provide a BASIC interpreter for the platform. The open S-100 bus fostered a thriving third-party expansion market, with companies like Processor Technology and Cromemco producing compatible hardware, establishing an ecosystem that propelled the industry forward.

Software and programming

Initially, programming was an arduous, machine-level process entered via the front-panel switches in hexadecimal code. The pivotal software development was Altair BASIC, the first product from Microsoft (then Micro-Soft), which made the machine accessible to a much wider audience. This interpreter was delivered on paper tape and later on floppy disk when storage systems evolved. Other early languages included Tiny BASIC and a version of the Forth programming language. The CP/M operating system, developed by Gary Kildall of Digital Research, later became the dominant software platform for S-100 bus systems, enabling a vast library of business and utility software.

Clones and derivatives

The success of the design spawned an immediate market for compatible systems and peripherals. The IMSAI 8080, introduced shortly after, became a major competitor and was famously featured in the film WarGames. Companies like Processor Technology with its Sol-20 and Cromemco built sophisticated S-100 bus computers that evolved beyond the original kit concept. The S-100 bus architecture itself was widely adopted and formalized later by the IEEE as a standard. Even IBM examined the machine during early research that would eventually lead to the IBM Personal Computer, cementing its indirect influence on the entire computing landscape.

Category:Microcomputers Category:American inventions Category:History of computing hardware