Amdahl 470 | 1970

Amdahl 470 

 In the early 1970s, IBM announced its new System/370 series. Initially, it had improved performance due to new electronics added over the System/360, and it was also more cost-effective. These changes allowed IBM to replace its older systems. Amdahl saw this as an opportunity and planned to create a low-cost version that could replace the high-end models of the 370 series. Amdahl anticipated that if IBM lowered the price of the high-end models, it would be forced to lower the prices of the lower-end models as well, and thus, IBM would be trapped in its own pricing structure.

Amdahl's goal was to create a product that could replace IBM's high-end systems, which led to the development of the "470/6." Amdahl's engineers worked with Fujitsu to develop a unique air-cooled chip based on high-speed emitter-coupled logic (ECL) circuits. These chips had cooling devices equipped with cylindrical pins that helped with heat dissipation, in contrast to IBM's systems, which were cooled with cold water. Amdahl's system, on the other hand, could be entirely air-cooled.

The system was initially designed for a 5x5 array per card but was later changed to a 6x7 array, evolving into a multi-layer card structure with a maximum of 14 layers. These cards were vertically arranged inside the computer chassis, and each card was connected by micro-coaxial cables. The CPU did not use a typical backplane, and each card column had three cards installed, with some exceptions having only two cards.

The system featured two large "Tarzan" fans—one blowing air out and the other pulling air in. These fans were essential for circulating large amounts of air to cool the system's chips. Each system also supported a CRT console with a Data General Nova 1200 and offered compatibility with IBM’s 3066 channel instructions.

At the time, the 370 series lacked virtual memory, which was criticized in the computer press. IBM announced in 1972 that it would introduce virtual memory, called Dynamic Address Translation, into the new 370 series. In response, Amdahl modified the design and released the 470V/6 model. This system, which took shape in 1974, offered double the performance of IBM's 370/168 at a similar price. Furthermore, it took up only a third of the space and had no water-cooling system, making installation and maintenance much easier.

The first 470V/6 system was delivered in June 1975 to NASA’s Goddard Space Flight Center, with installation and activation completed in just five days. This was significantly faster compared to the two to three weeks it would take to install a similar IBM system. The second system was delivered to the University of Michigan, and later to Texas A&M University and various computer companies. By August 1977, 55 systems had been installed, and the production line was expanded to produce four to six systems per month.

Amdahl and IBM fiercely competed in the high-end mainframe market, with Amdahl achieving a market share of up to 24%. One of Amdahl's key successes was due to the antitrust agreement between IBM and the U.S. Department of Justice. This allowed Amdahl's customers to use IBM's mainframe software on reasonable terms, and Amdahl’s systems were compatible with IBM’s 360 systems, allowing them to use 360's peripheral devices. Although IBM initially refused to provide maintenance for hardware connected to Amdahl’s systems, it eventually had to acknowledge this after Amdahl started benefiting from IBM's hardware maintenance.

In February 1977, Amdahl announced the 470V/6-II. This system had only 70% of the performance. Customers could pay $780,000 at any time to upgrade from the /5 model to the /6-II model. This system began shipping in September 1977.

Additionally, Amdahl introduced a "470 Accelerator" feature for the /5 and /7 systems, offering variable speed functionality that allowed customers to use the higher performance of the /6 and /8 systems when needed. This feature allowed customers to pay based on their usage time, managing costs while adjusting performance. Initially, it was expected to anger customers, but it turned out to be very popular, with customer managers able to easily adjust performance to meet their needs.