The first personal computers date from the mid-1970. The IMSAI 8080 belongs to the generation of microcomputers, and can be considered as the first " clone" of the computer industry. Indeed, this computer is almost identical to the successful Altair 8800, and despite having a difference in the front, both use the same microprocessor and S-100 bus. Many will remember IMSAI 8080 as the computer used David Lightman (Matthew Broderick) in the movie "War Games ."
If you read the previous article in this series dedicated to Altair 8800, remember that in mid 1970, the computer started to become somewhat popular. Until that time the cost of computers was sufficiently high that very few companies, universities or governments could afford one. But the Altair 8800-thanks to its form of marketing as " Kit to assemble" - gave rise to what became known as " PC " , a computer that almost anyone could buy and use at home. As often happens, the success of the computer made that many companies used the new market and try to keep a part of it.
The electronics industry, especially when it comes to microprocessors referred, was not particularly prolific in this period. When choosing parts to design a computer only a few alternatives existed. The Intel 8080 microprocessor was the best to assemble a computer, and its price hundreds of dollars, quite reasonable. Remember that until the appearance of the Altair computer kit " medium", built with discrete chips instead of using a microprocessor- could cost hundreds of thousands of dollars , so the 8080 price was a real temptation. That's how Bill Millard, a company called IMS associates decided that while the Altair 8800 was a fairly complete computer, had some shortcomings that should be corrected to become a team, "commercially viable " and created the IMSAI 8080.
http://www.youtube.com/watch?v=kb0EdBO_d50
Since 8080 was virtually identical to the product of competition, using the same S-100 bus and the Intel 8080 microprocessor - and that was compatible at the software level, it is considered as the first computer " clone" of history. Millard's work made it possible for holders of a IMSAI could connect up to 22 simultaneous expansion boards, thanks to a slightly larger case, could plug the S-100 bus perpendicular to the motherboard, virtually eliminating the existence of "false contacts " who suffered the Altair. To feed such a number of expansion cards IMS associates had to use a power supply more powerful, so the computer was a bit heavier than the original. The front panel, despite the limitations imposed by the lack of a display as modern, was much more aesthetically pleasing than the Altair. The Spartan " levers" were replaced with plastic keys in red and blue, while the remaining LEDs behind a clear acrylic.
had the same limitation as its source of inspiration as to how to enter and read data, you could buy an expansion card that allowed connecting a keyboard and a monitor. This allowed to forget the nightmare was loading a program using the panel switches and LEDs, of course at the expense of a little poorer. The characteristics of the team, such as shown in the advertisement appeared in the January of 1975 Byte magazine found below, were very similar to that of Altair.
As mentioned before, the Altair 8800 programs running in the IMSAI 8080. IMS sold a modified version of Altair BASIC and a version of CP / M allowing use an expansion card to connect units of 8-inch floppy . But all this was paid as "extra " basic price for the phone had only 256 bytes of RAM and you had to program the computer binary using the keys and LEDs on the front panel. The videos that accompany the text serve to give you an idea of \u200b\u200bwhat "fun " which was to use a computer in this way.
The IMSAI sold quite well, and the company claims to have shipped between 17 and 20 000 units from 1975 to 1978. had their five minutes of fame when the movie "War Games " - the same that inspired a generation of hackers - David Lightman (played by Matthew Broderick) had access to a computer through a defense phone connection using IMSAI 8080. Today can be seen only in museums or in the living-the-very lucky collectors who have managed to get one. Did you know him?
Source:
http://www.neoteo.com/retroinformatica-imsai-8080-1975.neo
0 comments:
Post a Comment