Category Archives: Computers

The first Cray-1® system by Cray Research (originally Control Data Corporation) was installed at Los Alamos National Laboratory in 1976 for $8.8 million. It boasted a world-record speed of 160 million floating-point operations per second (160 megaflops) and an 8 megabyte (1 million word) main memory. The Cray-1’s architecture reflected its designer’s penchant for bridging technical hurdles with revolutionary ideas. In order to increase the speed of this system, the Cray-1 had a unique “C” shape which enabled integrated circuits to be closer together. No wire in the system was more than four feet long. To handle the heat generated by the computer, Cray developed an innovative system using freon.

The MITS Altair 8800 was built by Ed Roberts, who founded MITS in the early 1970s. Originally producing lights for electronic hobbyists, they were heavily in debt by 1974. Roberts had a new idea, a computer affordable for the average person, and managed to make a deal with Intel to buy their processors for $75 a piece. Intel saw no market in the microcomputer game, but sold the chips to Roberts anyway.

With chip in hand, Roberts and colleague Bob Yates set about designing a “microcomputer” around it. Naming it after an episode of Star Trek, it was called the Altair. Roberts arranged a story in Popular Electronics magazine about the project, and readers discovered the first personal computer on the cover in January 1975. Computer hobbyists flooded MITS with orders, and the flabbergasted company scrambled to satisfy the demand. And despite the fact you couldn’t really do anything with it, techies all over enjoyed having a real computer to tinker with at home.

The Altair came with no monitor, keyboard or disk drive and in fact had no way to input/output information. It’s significance is that it spawned the microcomputer revolution as others began writing software and creating hardware to work with it. Microsoft was formed by Bill Gates and Paul Allen after writing the operating software for the Altair, which was a form of BASIC.

In 1974, Railway Express Railroad Co. lost Roberts’ only prototype on a trip to New York for review and photos with Popular Electronics.

Scelbi aimed the 8H, available both in kit form and fully assembled, at scientific, electronic, and biological applications. Designed by Nate Wadsworth and Bob Findley in 1973,  it was based on the Intel 8008 processor, and was the first microprocessor based kit to hit the market. It came with 1KB of RAM for It’s advertised price of $565. It had 4 kilobytes of internal memory and a cassette tape, with both teletype and oscilloscope interfaces. In 1975, Scelbi introduced the 8B version with 16 kilobytes of memory for the business market. The 8H was the first commercially advertised microprocessor-based computer in the U.S. The company sold around 200 machines, losing $500 per unit.

The Xerox Alto was designed at Xerox PARC in 1973. It was the first personal computer with a desktop/GUI. Designed by Chuck Thacker, it had 128kb of memory that was expandable to a whopping 512kb. It also held a hard drive with a 2.5mb cartridge, all inside a small refrigerator-size housing. It boasted a black and white CRT display, an Ethernet connection, three button mouse, keyboard, and chord keyset borrowed from the oNLine System. The Alto was also capable of input from a variety of devices, such as a tv camera, daisywheel printer, and sported a parallel port. It also had the ability to control external disk drives, making it a file server.

The Micral was the earliest commercial, non-kit personal computer based on a micro-processor, the Intel 8008. Thi Truong developed the computer and Philippe Kahn the software. Truong, founder and president of the French company R2E, created the Micral as a replacement for minicomputers in situations that didn’t require high performance.

The TV Typewriter was designed by Don Lancaster. It used $120 worth of electronics components, as outlined in the September 1973 issue of Radio Electronics. The original design included two memory boards and could generate and store 512 characters as 16 lines of 32 characters. A 90-minute cassette tape provided supplementary storage for about 100 pages of text.

Begun in 1969 by Allen-Bradley, MOS Technology originally was a supplier for Atari, but in 1975 they joined with ex-Motorola engineers to design and build low cost CPUs that performed better than leading CPUs like the Motorola 6800. The first MOS chip, the 6501, was four times faster than the 6800 thanks to it’s simpler design. Using an innovative way to reduce the errors in their manufacturing process, they were able to build the CPU at a much lower cost with a success rate of 70% or more.

Motorola sued MOS and effectively stopped sales of the 6501, but MOS released the 1 Mhz 6502 in September at the astounding price of $25. It was essentially the 6501 but with a different pin-out, and Motorola was not able to stop sales. Outperforming the 6800 and the Intel 8088, it eclipsed Motorola later and both companies reduced the price of their own chips to compete. Eventually the 6501 became one of the most popular chips on the market and a number of models were produced up to the 6507. The company continued to produce numerous chips and were bought by Commodore Business Machines after the collapse of the calculator market by Texas Instruments. MOS operated under the same name for several years even after being purchased outright by CBM. This merger eventually led to Commodore’s successful line of personal computers, but CBM went bankrupt in 1994. Although CBM had purchased the company, CPUs were produced with the MOS label stamped on them until 1989.

The Interface Message Processor (or IMP), was essentially the first router, as routers would eventually become known. It was the first device built with the purpose of switching packets across a network and was intended for use with the ARPANET. It was created by BBN in the early 1960s using a Honeywell 516 minicomputer with special interfaces and software. Later the Honeywell 316 was used.

The first IMP arrived at UCLA on Aug. 30th, 1969 and was connected to an SDS Sigma-7 computer. The second IMP was delivered to the Stanford Research Institute on Oct. 1st, 1969 and attached to an SDS-940. On Oct.29th, the first communication between the two systems took place. IMPs connected the ARPANET until it was decommissioned in 1989, with the last one shut down at the University of Maryland.

IMPs were the grandfathers of today’s network devices such as routers and switches, which carry network traffic to their destinations across the internet and networks. They were the first generation of gateways to interconnect the different networks connected to the ARPANET. Without such pioneers as BBN and ARPA, the internet as we know it today would not exist.

Edson deCastro was a former product manager at DEC, creators of the PDP series of computers. He left the company to form Data General and in 1968 they produced the Nova, competing directly with deCastro’s former employers. Although considered crude in comparison, the system was fast for it’s day and offered 16 bits over the PDP-8’s 12. One of it’s biggest innovations was the reduced manufacturing costs by being built on only two printed circuit boards that could be produced without any manual wiring. In contrast the PDP had many boards that had to be wired together. It was popular in industrial and lab settings.

Data General followed up with the SuperNova, then the SuperNova SC, both improving on the performance of the machine. The SC model was the fastest minicomputer of it’s day because of it’s 3.3 Mhz speed. The 1970s saw the Nova 1200, Nova 800, along with a few others. They later followed up with a slew of faster systems including the Eclipse series. The Nova influenced the design of the Xerox Alto, the Apple line from Apple Computer, and the MITS Altair.

The Apollo Guidance Computer was the first recognizably modern embedded system. It was developed by Charles Draper and the MIT Instrumentation Laboratory. Each flight to the moon had two of these computers. They ran the inertial guidance systems of both the command module and LEM.

The Apollo flight computer was the first to use integrated circuits. The computer consisted of roughly a thousand identical integrated circuits, NAND gates. They were interconnected by a technique called wire wrap, in which the circuits are pushed into sockets, the sockets have square posts, and wire is wrapped around the posts. The edges of the posts bite the wire with tons of pressure per square inch, causing gas-tight connections that are more reliable than soldered PC boards. The wiring was then embedded in cast epoxy plastic.