Altair 8800

Altair 8800
Swtpc6800 en:User:Swtpc6800 Michael Holley · Public domain · source
Name	Altair 8800
Developer	MITS
Manufacturer	Micro Instrumentation and Telemetry Systems
Release	1975
Discontinue	1977
Units sold	~5,000 (kits)
Cpu	Intel 8080
Memory	256 bytes–64 KB (expandable)
Storage	Paper tape, later floppy
Os	CP/M, Altair DOS, custom monitors
Predecessor	None
Successor	IMSAI 8080

Altair 8800 The Altair 8800 was a microcomputer kit released in 1975 that catalyzed the personal computer movement. It combined a backplane chassis, Intel 8080-based central processing, and a expandability philosophy that influenced firms such as Apple Computer, Microsoft, Commodore, Radio Shack, and IBM. Enthusiasts from communities around Homebrew Computer Club, Stanford University, Massachusetts Institute of Technology, and Harvard University engaged with its open architecture, sparking software and hardware ecosystems involving firms like Digital Research, Intel, Zilog, and National Semiconductor.

Development and Design

MITS, led by Ed Roberts (computer entrepreneur), conceived the design amid hobbyist markets served by companies such as Heathkit, Popular Electronics, Byte (magazine), and distributors including Radio Shack (Tandy) dealers. The product used a standardized bussing approach derived from earlier minicomputer practices at organizations like DEC and influenced contemporaries such as Fletcher-Terry clones. Its front panel switches and LEDs echoed control panels from machines at NASA, MIT Project MAC, and Bell Labs, while permitting expansion via S-100 compatible cards later adopted by firms like Processor Technology and Morrow Designs.

Hardware Specifications

The chassis featured a passive backplane with edge connectors supporting CPU, memory, and I/O cards. The board-level design centered on the Intel 8080 microprocessor and compatible components from suppliers including Intel Corporation and Mostek. Base memory began at 256 bytes and was expandable through modules developed by third parties such as Southerland Engineering and Altair-compatible vendors. I/O included serial interfaces for terminals like the Teletype Model 33 and storage adapters later enabling media from IBM-compatible floppy subsystems. Power was supplied by an internal supply influenced by switching regulator research at institutions including Stanford Linear Accelerator Center.

Software and Operating Systems

Early firmware consisted of monitor programs and bootstraps developed by in-house engineers and community contributors, paralleling efforts at Microsoft Corporation and Digital Research, Inc.. The platform enabled development of interpreters and compilers such as BASIC dialects, assemblers, and early operating systems including CP/M ports and disk operating systems influenced by Gordon Bell and Ken Thompson-era software practice. Third-party vendors provided language toolchains used in academic settings at MIT, University of California, Berkeley, and Carnegie Mellon University.

Impact and Legacy

The machine's market entry precipitated ventures by entrepreneurs like Bill Gates, Paul Allen, Steve Jobs, and Steve Wozniak, and influenced corporate strategies at IBM, Hewlett-Packard, and Sony. It prompted standards discussions involving IEEE committees and helped spawn trade shows and publications such as COMDEX, Computer History Museum exhibits, and issues of Byte (magazine), Compute!, and Popular Electronics. The hobbyist-driven model informed later platforms produced by Commodore International, Tandy Corporation, and Apple Computer, Inc., while inspiring academic research at MIT Media Lab and policy attention from legislators interested in emerging information industries.

Commercial Reception and Sales

Initially marketed via Popular Electronics and direct mail order, the kit sold thousands of units to hobbyists, labs, and small businesses, drawing interest from retailers like Radio Shack and distributors used by Heathkit. Sales performance encouraged competitors such as IMS Associates, Inc. and companies producing S-100 peripherals. Review coverage from publications including Popular Electronics, Byte (magazine), and Compute! highlighted both innovation and limitations, affecting purchasing decisions within user groups at Homebrew Computer Club chapters and university computing labs.

Community and Hacking Culture

A vibrant community formed around user groups, bulletin boards, and publications, with notable participants from Homebrew Computer Club, Stanford Artificial Intelligence Laboratory, and hobbyist chapters in Silicon Valley, Boston, and Seattle. The ethos combined experiments from makers influenced by Do-it-yourself culture exponents, collaborations with software outfits like Microsoft, and hardware modding reminiscent of exchanges at conferences such as SIGGRAPH and DEF CON. Hackers and engineers contributed monitor routines, peripheral designs, and language implementations that proliferated via newsletters, meetups, and early online services that later evolved into networks run by organizations like USENET and universities.

Category:Microcomputers