In business computing, the trend is away from centralized mainframes and toward s client/server networks that handle the computing needs of an entire enterprise. The article on page 8 is about the design of a new high-end HP corporate busine ss server that had the objective of setting new standards for commercial systems performance and affordability. The design is based on the HP PA 7100 CPU chip, a superscalar implementation of HP's PA-RISC processor architecture operating at a clock frequency of 90 megahertz. (Superscalar means that a processor can issue more than one instruction--typically 2 to 4--per clock cycle. The PA 7100 can issue two instructions--one integer instruction and one floating-point instruction--per clock cycle.) The new corporate business server can have up to twelve PA 7100 processors symmetrically sharing the workload, and performanc e increases approximately linearly with the number of processors. The internal bus structure is new. The design and protocol of the processor memory bus, which interconnects the processors and the memory system, result in excellent online transaction processing performance and efficient multiprocessor workshar ing. High input/output throughput is achieved by means of high-slot-count I/O buses arranged in a two-level tree. Main memory capacity can be as high as 2G bytes (2,147,483,648 bytes) of error-correcting memory and disk storage capacity can be as high as 1.9 Tbytes (1,900,000,000,000 bytes). A dedicated service processor reduces the time it takes to correct hardware failures. Depending on which operating system it runs, the new corporate business server is designa ted the HP 9000 Model T500 or the HP 3000 Series 991/995.

While the new high-end corporate business servers were being designed, another design team was working on making symmetric PA-RISC multiprocessing available to users of midrange HP 9000 and HP 3000 servers. The article on page 31 discus ses the design of a new processor board using two PA 7100 chips. By making one processor the "monarch" and the other the "serf" and deciding that if one proce ssor failed the other would not continue to operate, the designers eliminated most of the complexity in symmetric multiprocessing and were able to provide the basic performance advantages quickly and at low cost. The midrange servers that use this board are the HP 9000 Models G70, H70, and I70 and the HP 3000 Series 982.

The HP SoftBench Framework is widely used in the software development industry to create custom software development environments by integrating common softwa re development tools such as program editors, builders, and debuggers, static analyzers, electronic mail, and others. SoftBench Message Connector (page 34) is the new user tool interaction facility of the SoftBench Framework. It allows users of the framework to customize their environments quickly with simple point-and-click actions. For example, a text editor and a spell checker can be connected so that when the user saves a file with the editor, the spelling is automatically checked and the user is notified only if errors are detected. Tool interaction branching and chaining are supported so the user can create routines that use multiple tools and execute automatically without the user's explicitly invoking each tool. Message Connector is designed to require no training.

Contrary to my initial reaction on hearing the term, cleanroom software enginee ring doesn't mean development of software for the cleanrooms used in integrated circuit manufacturing. It's a metaphor for software engineering that mimics the way processes and the environment are carefully controlled and monitored in a cleanroom to ensure that the chips produced there are free of defects. The goal is nearly defect-free software, whatever its function. The article on page 40 explains the cleanroom methodology and software life cycle, and tells about the remarkable results achieved when the methodology was applied in a limited way in a typical HP environment.

In printed circuit board manufacturing, automated high-speed assembly machines are used to place components on the boards. In a manufacturing facility that produces multiple products at low to medium volumes, the machines must be set up in different ways to produce different products. While they are being set up they aren't productive, so a major concern is how to minimize the setup time. If the facility has more than one machine, another major concern is machi ne balancing, or how to assign products to the various machines most efficiently. An exact mathematical model of these problems is too complex too solve, so engineers at HP's Colorado Computer Manufacturing Operation resorted to fuzzy logic, a mathematical tool that's becoming more widely used for dealing with the inexact aspects of the real world. Using fuzzy concepts, they developed an algorithm for assigning printed circuit boards to families that use similar setups, and an algorithm for assigning the families to machines. The article on page 51 explains the problem, provides some basic fuzzy logic theory, descri bes the algorithms, and presents results. The fuzzy family assignment algorithm outperforms the greedy board algorithm, formerly the best available method.

R.P. Dolan
Editor