ACS
From 1965, Gene Amdahl had been working at IBM on the IBM Advanced Computer Systems project (ACS), which intended to introduce what would be the world's fastest computer. During a shake-up of the project in early 1968, Amdahl suggested that the company abandon the ACS-1 concept and instead use the techniques and circuit designs to build a System/360 compatible design. In a "shoot out" between the two concepts that spring, Amdahl's concept won. Many of the managers of the ACS left, and Amdahl was placed in charge of developing the new concept.
In July 1969, IBM sent out a memo stating that their older software was going to be released into the public domain and that new software would be sold as separate line items, not part of the purchase of a system. This was mostly due to ongoing antitrust investigations launched by 3rd party software companies like Applied Data Research, who complained that IBMs policy of giving away software was hurting the entire market. With the software now a separate product, Amdahl saw the possibility of IBM-compatible machines; if the software was sold separately, then IBM could not refuse to sell it to other computers or they would violate those same anti-trust rules.
In May 1969, Amdahl outlined a series of three machines developed from the ACS concept. This followed IBM's pricing model of offering a series of designs that were separated by about three times in performance and two times in cost, offering customers a reason to upgrade to a larger system. To make the top-end system affordable, it would have to be priced in a way that would push the prices of the smaller systems below what their current machines sold for. Management decided against the plans, and as this essentially ended the ACS effort, Amdahl suggested they shut down the lab. They did so, and Amdahl left the company shortly thereafter in early 1970, telling them of his plans to introduce compatible machines.
Foundation
Meeting with several other former ACS engineers, a new concept emerged. Instead of attempting to make the fastest computer using the most tightly packed circuit boards possible with current technology, they would instead design a much looser arrangement of five by five components on a standardized card. Although a machine using these cards would not be able to run as fast as ACS, they would be much easier to design and cheaper to build. A key concept in the system was the automated layout of the circuit board interconnections using software running on IBM 1130 computers. Looking for partners to produce the circuits, they found Motorola was interested in doing so as long as Amdahl would provide the routing software to them first. Amdahl concluded they would take the software and not deliver the chips. After talking to National Semiconductor and Texas Instruments with no result, they finally signed with Advanced Memory Systems.
The company found it extremely difficult to arrange funding for development. Much of this was due to the venture capital industry's feeling that attempting to compete with IBM was doomed; RCA had spent billions developing and marketing their Spectra 70 series and had yet to come close to a profit, while Xerox had attempted a different attack by buying Scientific Data Systems and was suffering as a result.
470 series
During this period, IBM announced their new System/370 series. These were, initially at least, System/360s with new electronics that allowed them to run faster and be less expensive in comparison to the 360s they replaced. Amdahl's new target was to offer a lower-cost version of the high-end member of the 370 family. Amdahl felt that this would trap IBM in their own pricing structure; if they lowered the cost of their high-end machine to compete, to keep their pricing structure they would be forced to lower the cost of their lower-end offerings where they made much of their profit. The new machines were given the name 470/6.
Amdahl engineers, working with Fujitsu circuit designers, developed unique, air-cooled chips which were based on high-speed emitter-coupled logic (ECL) circuit macros. These chips were packaged in a chip package with a heat-dissipating cooling attachment consisting of a cylindrical arrangement of fins, similar to the heat-dissipating fins on a motorcycle engine, mounted directly on the top of the chip. This patented technology allowed the Amdahl mainframes of this era to be completely air-cooled, unlike IBM systems that required chilled water and its supporting infrastructure.
Originally designed for a five-by-five arrangement of components on a card, during development this evolved into a six-by-seven array on multi-layer cards (up to 14 layers), which were then mounted in vertical columns in the computer chassis. The cards had eight connectors attached to micro-coaxial cables that interconnected the system components. A conventional backplane was not used in the central processing units. The card columns held at least three cards per side (two per column in rare exceptions, such as the processor's "C-Unit"). Each column had two large "Tarzan" fans (a "pusher" and a "puller") to move the considerable amount of air needed to cool the chips. Each system included a Data General
Later 470s
In February 1977, Amdahl announced the 470V/6-II, which offered 5 to 15 percent greater performance but at a slightly higher cost. The next month they announced the 470V/5, a smaller system based on the same circuitry that offered about 60 to 70 percent of the performance of the 6-II. Customers could upgrade from the /5 to the /6-II at any time for $780,000. Deliveries began in September 1977. At the same March announcement, they also introduced the 470V/7 as competition to the recently announced IBM 3033 system, a re-implementation of the 370 series using newer circuitry and incorporating some ideas from the ACS project. The first /7's shipped in August 1978.[6]
The 470V/8, first shipped in 1980, incorporated high-speed 64 KB cache memories to improve performance, and the first real hardware-based virtualization (known as the "Multiple Domain Facility").[7][8]
Amdahl also pioneered a variable-speed feature - the '470 accelerator' - on the /5 and /7 systems that allowed the customer to run the CPUs at the higher level of performance of the /6 and /8 systems, respectively, when desired. The customer was charged by the number of hours used. Some at Amdahl thought this feature would anger customers, but it became quite popular as customer management could now control expenses while still having greater performance available when necessary.[9]
580 series
In the late 1970s, Amdahl began an effort to develop a next-generation systems architecture under the 580 project. Both the Amdahl engineering teams and Fujitsu strongly suggested developing a multi-processor architecture. Gene Amdahl was against this and wanted to develop a faster single processor. Things came to a head in 1979, and Amdahl left the company in August to start Trilogy Systems. With Gene Amdahl's departure, and increasing influence from Fujitsu, Amdahl entered the large-scale multiprocessor market in the mid-1980s with the 5860, 5870 (attached processor) and 5880 (full multiprocessor) models.
In the 580 systems, the chips were mounted in an 11-by-11 array on multi-layer boards called Multi-Chip Carriers (MCCs) that were positioned in high-airflow for cooling. The MCCs were mounted horizontally in a large rectangular frame. The MCCs slid into a complex physical connection system. The processor "side panels" interconnected the system, providing clock propagation delays that maintained race-free synchronous operation at relatively high clock frequencies (15–18 ns base clock cycles). This processor box was cooled by high-speed fans generating horizontal airflow across the MCCs.
Along the way, Amdahl came to believe that its best bet at competing with IBM head-to-head was to "bulk up", in particular, executing a merger with a well-known vendor in the enterprise storage space. Most Amdahl mainframe customers would purchase storage devices (hard disk and tape drives) from IBM or its plug-compatible competitors. Amdahl first attempted a merger with one of the largest of these vendors, Memorex, in 1979. After this deal fell through, Amdahl went much further on a deal to merge with Colorado-based Storage Technology Corporation (STC). The deal was approved by the boards of both companies, and detailed plans were in place to implement the merger, when Fujitsu
Market exit
In 1987 Amdahl announced that it ended Aspen, a project started seven years earlier to create a proprietary operating system, and instead would focus on Amdahl UTS, its Unix operating system.[12]
By the early 1990s, Amdahl was suffering losses of several hundred million dollars per quarter as a result of declining mainframe sales. Management decided to lay off 900 employees in 1992, 1,100 in early 1993, and another 1,800 (out of the 7,400 remaining) later in that year, as well as canceling hardware development projects in favor of reselling computers from Sun Microsystems.[13]
Amdahl perhaps enjoyed its best success during IBM's transition from bipolar to CMOS technology in the early to mid-1990s. The first generations of IBM's CMOS mainframe processors, the IBM 9672 G3 and G4, could not perform as well as those from the Enterprise System/9000 family, which were based on bipolar technology, giving Amdahl a temporary advantage. However, IBM's CMOS strategy paid off in the long run, allowing IBM's Poughkeepsie factory to produce even faster mainframes at a lower cost as the technology matured. By the time IBM introduced its 64-bit zSeries 900 in 2000, Amdahl's hardware business could no longer compete with IBM with its Millennium and OmniFlex servers that only had
