IMSAI 8080
Announced:August 1975
How many:Around 20,000
Price:US $931 assembled
US $599 as a kit
CPU:Intel 8080A, 2.0 MHz
RAM:64K max
Display:front panel LEDs
Controls:front panel switches
Expansion:card-cage w/ S-100 bus
Storage:optional cassette or
floppy drive
OS:CP/M, BASIC





Built by IMS Associates, Inc. of San Leandro, California, the IMSAI 8080 is one of the first consumer computers available.
True, there were other, earlier computers, but most were available in kit-form only, requiring long and complicated assembly. The IMSAI was certainly the best-looking of the early micro-computers, and was sold as both a kit or already-assembled and tested. The kit version was hundreds of dollars cheaper, but it took many long days of careful soldering and assembly to create a (hopefully) working IMSAI.

In its simplest configuration with only a CPU (Central Processing Unit) card, you enter your program using the front panel switches, while reading the results on the LED indicator lights. No keyboard or other display is necessary. This type of programming is very slow and tedious - any mistake could corrupt the system and you'd have to start over again. Only true hackers were successful at efficiently operating an IMSAI 8080.


Like all early S-100 based systems, the IMSAI is really just a large metal case with a power supply, and numerous slots to insert the expansion cards. But due to the limitless expandability afforded by the S-100 bus design, an actual keyboard, monitor, printer, data storage, and other peripherals can all easily be added to make this a very useful system.

Some call the IMSAI the first clone of another computer system, in this case, of the MITS Altair 8800, a similar computer which was release just a few months earlier. It will even accept the same cards as the Altair, because of the S-100 bus design. The IMSAI was not the only computer to copy MITS' S-100 bus scheme, but it may have been the first.



This was the true beginning of 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!".

Unfortunately, these early computer systems were very difficult to program and operate for the general public, and there was very little software available. Within just a year or two, more user-friendly computers appeared on the market, and IMS Associates, Inc. filed for bankruptcy in 1979.


Fans of the movie Wargames may remember seeing the IMSAI 8080. Look for it next time you watch!

Related Links

  • The official home page of IMSAI
  • IMSAI 8080


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