MITS Altair 8800
Introduced:January 1975
Available:February 1975
Prices:US $395 as a kit
(prior to March)US $650 assembled
How many:estimated 2000+
CPU:Intel 8080, 2.0 MHz
RAM:256 bytes, 64K max
Display:front panel LEDs
Controls:front panel switches
Expansion:Altair-bus card-cage
Storage:paper tape, cassette or
floppy drive

The Altair 8800 from Micro Instrumentation Telemetry Systems (MITS) of Albuquerque, NM, is considered by many to be the first "personal computer" - a computer that is easily affordable and obtainable.

At this point in time, there were no computer or electronic stores to buy your own computer. The only options were to build your own system from plans and designs published or sold in magazines and other sources. It was the individual owner's responsibility to find and acquire all the parts necessary to assemble it.

The Altair 8800, was first featured in the January and February 1975 editions of Popular Electronics magazine, although this early design bore little resemblance to the finalized version released just a few months later. Up until this point, MITS was known for selling calculators and model rocket components (telemetry).

For just $439, the Altair 8800 for the first time included everything in one kit - assembly instructions, metal case, power supply, and all of the boards and components required to build "the most powerful computer ever presented as a construction project in any electronics magazine".

It took many days and nights of careful soldering and assembly to hopefully create a working Altair. Only true hackers would undertake such an endeavor.

Ed Roberts, the owner and president of MITS, is also the designer of the Altair 8800.

Roberts was able to acquire the new and powerful Intel 8080 CPU for $75 each in large volume, when they normally sold for over $300 each. These cosmetically blemished chips worked just as well as the more expensive ones, and allowed the Altair 8800 to be released at a very low price.

The system seen here on the right has two additional circuit boards installed, but the CPU card is the only one required to have a working system.

The entire Altair 8800 system is comprised of a metal case, a power supply, a front panel with switches, and a passive motherboard with expansion slots. All of the circuitry - the CPU and memory, are on cards which plug into the expansion slots, which MITS called the "Altair Bus".

This became a very easy and popular method of designing computers, and numerous other systems from competing manufacturers were released utilizing the same Altair Bus - the IMSAI 8080 was the first - the first computer clone. The Altair Bus became an industry standard, but MITS didn't appreciate it being renamed as the S-100 bus (it has 100 pins).

Since no keyboard or monitor was cheaply available, users initially had to flip switches on the front panel, writing their own programs in machine language, and watching the LEDs on the front panel light up in response to their commands.

Due to the flexibility of the S-100 bus, numerous expansion cards were soon released, including a keyboard interface, TTY, monitor, printer and data storage, adding greatly to the Altair's usefulness.

Additional Altair cards available from MITS:
Functionkit priceassembled
1K static RAM$97$139
2K static RAM$145$195
4K dynamic RAM$195$275
Serial interface$119$139
Parallel interface$92$114
Cassette interface$128$175

Bill Gates and Paul Allen saw an opportunity and wrote Altair BASIC, a true programming language. Monte Davidoff contributed maths routines, including the floating-point routines for Altair 4K BASIC. Altair BASIC was very expensive at $500, but only $75 when purchased with an Altair computer, an interface board, and 8K of memory.
Soon after, Gates and Allen formed their own company - Micro-Soft, and sold Altair BASIC as their first product.

Why was the computer named "Altair"? The name was decided upon by Popular Electronics magazines, but there are two versions of the story:
  1. The first and most popular, that the name came from Star Trek the TV series, is apparently false, but it sounds good. The story is, that Les Solomon, the (then) technical director of Popular Electronics magazine (and a great story teller), asked his daughter about a name, and she suggested "Altair", because "that's where the Enterprise is going in this episode" - she was supposedly watching Star Trek, the science fiction TV series. Altair was mentioned in only one Star Trek episode: "Amok Time", episode 34 - original airdate: 9/16/1967.

  2. Alternately, Forrest M. Mimms III states in the November 1984 issue of Creative Computing that the Altair was originally going to be named the PE-8 (Popular Electronics 8-bit), but Les Solomon thought this name to be rather dull, so Les, Alexander Burawa (associate editor), and John McVeigh (technical editor) decided that "It's a stellar event, so let's name it after a star." McVeigh suggested "Altair". Actually, there really is a star called Altair - it's the 11th brightest star in the sky.
In January 2005, John McVeigh wrote me a message confirming the second account, and reminiscing on the good ol' days at Popular Electronics!

This was the true beginning to the computer age!

In September 1975, the very first issue of BYTE magazine was issued. On the cover they proudly state: "Computers: The worlds greatest toy!".

Even though MITS developed additional and more advanced models, and shipped thousands of Altair computer systems a month, the company was sold to Pertec in 1976. Pertec continued producing Altairs, but did a very poor job of it, and within a few year, the Altair line of computers disappeared into history.

Related Links

  • The Virtual Altair Museum
  • Altair 8800 from Obsolete Computer Museum
  • Altair 8800 documents from Pat and Randy Wilson
  • Altair 8800 from System Source Computer Museum
  • The Stan Veit story
  • InfoWorld - Feb 1980
  • "The Altair story; early days at MITS"

  • Return to the Obsolete Technology Homepage