Electrophoresis refers to the movement of molecules through a fluid or gel under the influence of an electric field. It is useful for separating the components of a mixture, since different molecules move at different rates. Gel electrophoresis has become familiar as a result of the DNA spot patterns seen frequently in the news media. In capillary electrophoresis (CE), the gel is replaced by a fluid inside a capillary, a glass tube about the size of a hair in diameter and about a meter in length. Near the end of the capillary is a detector, which measures the amount of light absorbed by the fluid in the capillary. As the various molecules, now separated into bands, pass the detector, the detector output voltage describes a series of peaks that can be analyzed to determine what was in the mixture and how much of each component was present. In some cases, CE makes analyses possible that can't be done otherwise. In other cases, it provides useful confirmation of analyses done by other methods. For these reasons, CE has become an established separation method along with gas chromatography (familiar for pollution analysis) and liquid chromatography (drug testing). The article on page 6 provides a more detailed introduction to this relatively new analytical technique and recounts the history of CE research at HP, which has led to the development of the new HP G1600A capillary electrophoresis instrument described in the article on page10. The objectives for the design of this instrument were to overcome the perceived limitations of existing instruments in the areas of automation, sensitivity, reproducibility, usability, and information output. Major contributions to the sensitivity and information objectives are made by the detector and capillary designs. The detector (page 20) is a diode array detector, which measures light absorption over a range of wavelengths, thereby providing spectral information that's useful in identifying unknown compounds. Sensitivity is improved by a new optical design of the detector and an improved deuterium light source. The detector works eith with standard capillaries or with capillaries that have an extended lightpath, a bubble three to five times the diameter of the capillary, which helps increase the amount of light absorbed, thereby improving the signal-to-noise ratio. Details of this "bubble cell" technology can be found in the article on page 62. Contributions to the automation and usability objectives are made by the design of the capillary handling and sample injection techniques (pages 25 and 32 ), by the separation control electronics and firmware (page 36), and by the user interface design (page 44). Capillaries are mounted in cassettes, and all the necessary connections between the capillary and the rest of the system are made automatically when the cassette is inserted. Temperature control, vial movement and pressurization, capillary flushing, sample injection, and buffer liquid replenishment are also handled automatically under program control. The user interface is implemented in HP ChemStation software running on a personal computer. Analytical methods are developed and tested (by simulation) on the ChemStation and downloaded to the CE instrument, where they run automatically. The reproducibility of each instrument is verified by an extensive final test procedure as described in the article on page 50. CE research at HP is continuing in several areas including the treatment of capillary surfaces for protein analysis, as described in the article on page 57.

What happens if your PC's hard disk-or worse, your network server's hard disk-crashes? RAID technology (RAID stands for Redundant Array of Inexpensive Disks) offers PC-based systems cost-effective data protection against a disk failure by providing an array of disk drives under the command of a single controller. HP Disk Array (page 71) delivers RAID data protection along with other features such as predictable failure notification, automatic failure detection, and automatic disk-failure recovery. Many RAID systems are hard to install and configure and do not make it easy to recover from a disk failure. HP Disk Array comes with software utilities that address this problem. The hardware also offers ease-of-use features such as automatic identification and the ability to replace a disk drive while the system is in operation.

COBOL is still the preferred programming language for a large number of critical business applications. Many companies are now moving these applications to open systems. COBOL SoftBench (page 82) gives software developers the tools they need to make this transition without having to rewrite their applications in another language such as C or C++ (they can, if they wish, use these languages for some routines and COBOL for others). The widely used SoftBench CASE (computer-aided software engineering) environment provides a highly integrated toolset that includes a program editor, a program builder, a static analyzer, a COBOL animator, a COBOL profiler, a file comparator, and email, along with dozens of third-party tools. A mouse, a menu-driven user interface, graphical views of complex programs, and automation of repetitive tasks using the SoftBench message connector improve productivity and minimize the learning curve for novice users.

Two papers in this issue are from the 1994 HP Design Technology Conference. Designers of a custom integrated circuit needed to provide their chip vendor with documentation describing the data path and control portion of their chip. The article on page 88 explains how they used commonly available electronic schematic capture software to ensure that the documentation they provided always matched the descriptions they were using for simulation. In designing an interface between a 60-megahertz bus and a 120-megahertz bus, one HP design group chose to use standards cells and automatic place and route tools instead of a custom design (page 92 ). They recommend the approach for its reduced risk and the ease of making design changes.

R.P. Dolan
Editor