The importance of testing complex electronics
The increasing functionality of modern electronics systems is being achieved through more complex integrated circuits, dense surface mount assemblies and increasingly through the use of multiple complex ICs interconnected to form multi-chip modules, all of which have progressively increased the cost of testing and its share of production cost, so that test costs are dominant today. Initiatives taken in Europe by leading corporations and recently adopted as IEEE standards for logic circuit testability, are now enabling electronic access for in-circuit testing and diagnostics at IC and board and MCM level, thereby improving quality and throughput in the manufacture of electronics. various proprietary solutions are also being introduced very effectively for analogue circuits, and for specialised computing and telecommunications systems, some using expert systems to aid diagnostics and improving the quality and throughput of testing. The solutions are most cost-effectively introduced at the design stage when maximum impact can be achieved on subsequent life-cycle costs.
Chip Carrier Based Systems and their Testability
Testing has become one of the dominant costs in the process of bringing a product from initial conception to the market place. Because of this, it is now imperative that the impact of any technology change on the test process is considered at an early stage. In this light, the increasing trend towards the use of surface‐mounting techniques in the fabrication of electronic systems is examined, with particular emphasis on the consequences on product testing during design validation, manufacture and repair. The aim is to highlight areas in which new attitudes and replacements for traditional solutions will be needed if surface‐mounting techniques are to be as cost‐effective as possible.
Diskless linux system with unionfs for an educational computer center
The total cost of ownership is a major concern for computer centers that maintain hundreds of PCs. From our experience, it would be most important to reduce hardware faults, particularly the troubles of hard disk drives. This paper describes how we built our educational computer system using diskless PCs. Before constructing our system, the following items were listed as the objectives of client PCs: (1) run Linux, (2) work without local HD, (3) deploy a single OS image to all PCs, (4) be easy to update the OS image, (5) be applicable to as many device configurations as possible, (6) become clients for unix servers (Linux, Solaris, AIX, etc.), and (7) use open sources. We chose Vine Linux 3.1, which is a derivative of RedHat Linux and is well organized for Japanese language environment. To satisfy (3) and (5), we introduced unionfs which has stackable file system feature. The system directories and files dependent on each PC such as /tmp, /dev, /var, /etc/mtab, and /etc/fstab are generated as memory files systems in the boot procedure, and are stacked on the common OS image using unionfs. Since this stack mechanism was implemented only by adding some hook codes to /etc/rc.d/rc.sysinit, our idea, we believe, is applicable to other Linux distributions. Our educational computer system consists of 8 servers, 12 boot servers and 500 diskless PCs, and is now in operation.