Power PC Products

The following is a preliminary sketch of the history of the IBM-Bull alliance concluded in 1992. As this alliance is still in force, this paper does not mention the current developments in that area and limit itself to a report of the pre-Gestner period inside IBM..

the Quest for RISC

The year 1991 saw a big turmoil among the "strategists" and the engineers who were involved in Unix product lines. It appeared in 1Q 1991 that MIPS had no more the capability of fulfilling the hopes that many (DEC, Siemens, SGI) have placed in the microprocessor integrated version of their RISC architecture. MIPS strategy became somewhat confusing, they teamed with Microsoft on Windows/NT, they started to court Silicon Graphics. In fact, Bob Miller was looking for money, something that Bull that have already paid for Ridge was not ready to commit.

Bull decided that a new alliance was needed, an alliance for which, Bull's shareholders (France Télécom and the French Government) were ready to open the capital of Bull.

Edith Cresson, then chief of  government, had even her favorite: it was Hewlett-Packard and its HP-PA architecture. H-P was proposing to Bull an alliance that gave to Bull distribution rights and technical informations on HP-PA products, while Bull would commit to base its future products on that architecture.

IBM was  ready to fight the risk of having a competitor to be in the position to use Bull sales channels to attack the European medium scale market, where IBM was struggling trying to dominate with AS/400 and RS-6000. IBM identified some weaknesses in its Austin engineering operations and considered that the reinforcement of it through a joint venture with Bull could help IBM position. And IBM started to court Bull. The IBM push became stronger after the announcement of the PowerPC deal with Apple and Motorola, while Bull had never envisioned teaming with Apple on the personal computer area.
There were also discussions with DEC, in 1991 where DEC informed Bull of the coming Alpha architecture. But DEC was not yet ready to commit on products and they were still playing with MIPS. They were not interested either to take shares in Bull.
Somewhat, surprisingly, the Intel architecture was dismissed by Bull (IA-64 was yet to be heard about) and Sun Microsystems was not seriously envisioned  (Sun showing less interest to disseminate its architecture outside the company).

Bull's CEO Francis Lorentz chose IBM relatively early. IBM looked humble and respectful in that period, they agree to buy 5% of Bull, they did not limit the scope of the cooperation to sell OEM RISC systems, but they were ready to open their technology, to extend the cooperation inside the PC area by buying Zenith made laptops, to have Angers manufacturing boards for IBM... Lorentz succeeded to get the backing of the minister of Industry, Dominique Strauss-Kahn against the prime minister  and finally got the IBM alliance in January 1992 ... but was fired three months later, for having challenged the H-P deal preferred by its shareholder.


The immediate consequence of the IBM deal concluded in January 1992 and definitively signed in April was to have Bull introducing the IBM RS-6000 in its catalog. The product was manufactured in Austin and were sold under Bull logo as DPX/20.   Workstation and severs were announced, but the majority of Bull sold systems were servers replacing in Bull's offer internally produced DPX/2.


The main development undertaken under the PowerPC deal was a joint development of a SMP (up to 8-ways) version high-end server. It was code-named Pegasus and was to be sold by IBM and by Bull (the latter, under the brand name Escala). Pegasus main responsibility for hardware was assigned to Pregnana laboratory. Several models were developed, initially with IBM-Motorola 601 microprocessor, later with Motorola developed 604 microprocessor. Bull Italia (with the architect Angelo Ramolini)   designed developed the arbitration and cache management circuitry as well as board layouts with the attendance of some engineers dispatched to Milan. The I/O architecture was derived from RS-6000 (micro-channel architecture), while Bull added the attachment of a Data General Clariion subsystem. The software was a new version of AIX that included shared memory multi-processor support developed in Austin with Echirolles engineers. Bull-Echirolles also contributed to the development of prototypes and was Bull's support center for AIX.

The Escala product line was revamped in 1995, when it introduced the Intel PCI bus instead of the more expensive and less performing micro channel. PCI also gave to the system access to the peripherals designed for the PC market and allowed Escala to compete in cost with Intel based servers. This introduction reposition downwards the Escala line by limiting it to quad processors.

Bull, in Les Clayes, attempted to work on a massive multiprocessor PowerPC system, but that project went nowhere, caught between clusters of Escala and IBM SP (supercomputer based on Power architecture, not an Austin project) and unable to embark on a "proprietary" version of AIX.

Clusters of Escala have been sold, successfully,  by Bull with a customized version of AIX. Bull attempted also to sell this configuration at mainframe prices, by bundling several packages of software with a specially tuned AIX (project Sagister). The market reaction was negative and this direction was discontinued.

Motorola venture in computer market

Bull has also sold Motorola designed and manufactured workstations under AIX, named by Bull Estrella with a limited success. One possibility was that they also were able to run Windows/NT 3.1. But Microsoft abandoned the support of the PowerPC (as MIPS)  by Windows/NT and Motorola did not maintain that product line.

A Windows/NT solution

It should be noted  that Bull introduced in 1998, a new line of servers Express/5800 produced by NEC on Intel Pentium architecture under Windows/NT. Those servers were positioned slightly below Escala, but in the same SMP server market. The customers have the choice to get NT and to adopt the 5800 or to get UNIX and PowerPC systems.

Temporary conclusion

The PowerPC deal did not go as smoothly as contemplated at the beginning of 1992. Bull reduced its commitment in the PowerPC microprocessor, by taking only  a token presence in Somerset design center in Austin, and by not buying derivative rights on the architecture. A second blow happened when IBM Rochester decided to make its own version of the PowerPC instead of model 620  as initially contemplated. Michael Armstrong, who have been the chief IBM instrumentor of the agreement leaved IBM for Hughes and eventually AT&T. Lou Gerstner decided to stop the centrifugal strategy of his predecessor and to re-center IBM on mainframes, significantly decreasing the Austin hopes of seeing the PowerPC as the IBM core architecture. The disappointing sales of Apple, close to be driven away from the hardware market until 1998 iMac, also compromised the future of the PowerPC.

The strategy changes inside IBM and the Motorola's withdrawal modified somewhat the Bull AIX offer that added in 1998 IBM servers using the Rochester processors (under AIX only).


Revision : 19 février 2002.