The 32 bit microprocessor-a recipe for computation

The largest microprocessors now rival early mainframe computers in computational ability, and are invading areas once considered the prerogative of mini and mainframe computers. Microprocessors with 32 bit data buses are currently the largest members of the microprocessor family and a number of different makes are now readily available. The best known are probably the Motorola MC68020, the National Semiconductor NS 32032 and 32332, and the Intel 80386, although several others types exist. The author discusses how they differ from their smaller predecessors, and describes some of the new developments in personal computing that they have brought with them. The author discusses 8 bit and 32 bit processors, segmented memory, paged memory, virtual memory, cache memory, internal architecture, instruction sets, and coprocessors     

Intelsat planning and modelling software in support of IDR

In order to plan for and integrate intermediate data rate (IDR) carriers into the INTELSAT newtork, while achieving quality service with efficient use of resources, operational planning tools and transmission system models are necessary. These computer software tools and models, which have evolved and grown in parallel with the INTELSAT network, comprise numerous applications on various types of computers, including mainframe, mini and personal computer systems. This paper presents an overview of the major planning and modelling software models used at INTELSAT in support of the use of IDR digital carriers within the INTELSAT system.     

Magnetooptics: A thermomagnetic recording technology

Erasable magnetooptic (MO) recording is viewed as a possible successor to electromagnetic recording that is used today in high-performance disk drives for mainframe computers, hard disks, and floppy disks for personal computers and magnetic tape drives. A large number of rare earth-transition metal alloys have been investigated for use as the magnetic recording material. The properties of the films are very sensitive to the film deposition processing parameters. Accelerated life tests show that there are magnetooptic materials that do have all of the necessary properties and stability for use in computer digital storage.     

Comparison of a simulation and an exact method for reliability evaluation of large networks using a personal computer

An analysis of the relative merits and demerits of a simulation and an exact method for system reliability evaluation is presented. The comparison is performed using computer programs developed on a personal computer. The networks used in the analysis are randomly generated. Although computer implementations of some system reliability evaluation methods are available in the reliability literature, the programs are not portable. Most of the programs were developed either on a mainframe or a mini computer in different software environments. Due to the recent developments in computer technology, extremely fast personal computers are available. The emphasis of this paper is on the use of a standard personal computer, such as the IBM-PC or a compatible, in order to develop and compare computerized algorithms.     

Digital signal processing

Markets have always influenced the central thrust of the semiconductor industry. Beginning in the early eighties, the personal computer (PC) market has been the dominant market influencing the semiconductor industry. Single-chip microprocessors (MPUs) enabled what became the huge PC market, which ultimately overshadowed the earlier minicomputer and mainframe computer markets. The popularity of PCs led to investments in increasingly more powerful MPUs and memory chips of ever-growing capacity. MPUs and DRAMs became the semiconductor industry technology drivers for the data processing needs of the PC. But now, DSP, as opposed to conventional data processing, has become the major technology driver for the semiconductor industry as evidenced by its market growth and the fervour of chip vendors to provide new products based on DSP technology. The increasing need to digitally process analog information signals, like audio and video, is causing a major shift in the semiconductor business. Since DSP is the mathematical manipulation of those digitized information signals, specialized math circuitry is required for efficient signal processing-circuitry that was previously confined to classical DSP chips     

电子海图与雷达背景信息叠加显示关键技术研究

现有的电子海图导航系统主要靠全球定位系统（GPS）来测量舰船的地理坐标，用雷达信号适时检验GPS的定位精度就成为电子海图系统不可少的功能。为了能对雷达的大量数据进行实时处理以及在计算机上进行显示，文章讨论了雷达背景信息的高速采集和极坐标一直角坐标高速变换的硬件实现。采用该方法，普通PC机即可对雷达回波信号进行实时处理并与电子海图进行叠加显示。     

计算机中几个热点技术的回顾与展望

通过回顾计算机CPU技术的发展，微软新视窗XP系统的应用，Internet宽带上网以及Pentium4 DDR内存 845D芯片组的PC时尚，展望未来，二十年内PC功能或许将追上人脑。最后指出，当前计算机教育要“与时俱进”。     

A scattering-type transverse resonance technique for thecalculation of (M) MIC transmission line characteristics

A scattering-type formulation of the transverse resonance technique is introduced and applied to a variety of currently practical (M) MIC configurations. By utilizing a reflection coefficient matrix representation of boundary conditions, the characteristics of open, conductor-backed and shielded microstrip, slotline, or coplanar waveguide can be calculated. Excellent agreement with measurements and theoretical data on fundamental and high-order mode characteristics is obtained. In contrast to other methods, which require mainframe support, the software based on this formulation is operational on 386-compatible personal computers     

A universal matrix solver for integral-equation-based problems

A new method has been developed for compressing the matrices that occur in most integral-equation-based computer programs. This method is easy to interface with existing computer programs, and allows them to run significantly faster and with significantly less memory. This method applies not only to electromagnetic and acoustic computation, but also to most programs involving a Green's function or any integral equation with a kernel having some smoothness properties. Our numerical computations, running on a high-end personal computer, have achieved compression ratios of fifty times, and compressed inversion of the matrices fifty times faster than by previous methods. For larger problems, solved on high-performance computers, these ratios would improve to about one thousand to one for larger moment method problems.     

High-speed sensing techniques for ultrahigh-speed SRAMs

Two high-speed sensing techniques suitable for ultrahigh-speed SRAMs are proposed. These techniques can reduce a 64-kb SRAM access time to 71~89% of that of conventional high-speed bipolar SRAMs. The techniques use a small CMOS memory cell instead of the bipolar memory cell that has often been used in conventional bipolar SRAMs for cache and control memories of mainframe computers. Therefore, the memory cell size can also be reduced to 26~43% of that of conventional cells. A 64-kb SRAM fabricated with one of the sensing techniques using 0.5-μm BiCMOS technology achieved a 1.5-ns access time with a 78-μm² memory cell size. The techniques are especially useful in the development of both ultrahigh-speed and high-density SRAMs, which have been used as cache and control memories of mainframe computers     

Millimeter-wave range for the quick evaluation of large reflector antennas with complex feeds

An automated millimeter-wave antenna range capable of measuring primary-feed structure patterns and transferring this data to a mainframe computer for secondary pattern computation is described. Its applicability to the rapid evaluation of complex feed structures as used in a Cassegrain antenna is illustrated. An example of a reflector antenna analysis is compared to a measured pattern.     

Technology 1991: PCs and workstations

Significant developments during 1990 in the areas of personal computers and workstations are discussed. Laptops and notebook-size machines composed the fastest growing segment of the personal computer marketplace. Other notable announcements including a broad range of engineering workstations, with RISC computers breaking the US $5000 barrier. Peripherals also spurred great activity. Hard-disk drives continued to get smaller while growing in capacity, floppy disks jumped up to the superfloppy arena with an order-of-magnitude boost in storage capacity, and IC memory cards were on the verge of making their mark as replacements for rotating magnetic-disk memory     

Memory systems for highly parallel computers

Some recent developments in computer memories are discussed, and proposals are made to enhance the memory systems of highly parallel SIMD (single instruction multiple data) computers. The topics covered include increases in density and speed; adding new logic functions to memory chips; local autonomy in addressing; a parallel indexed RAM (PIRAM); impact of memory on numerical computation in SIMD; routing data among processing elements (PEs); bottlenecks; iconic and symbolic processing; a mesh-interfacing memory chip; bimodal memory system; and local address autonomy using PIRAMs     

Unified alignment of isdn-relevant information communications services/applications through a cubic framework

A cubic (three-dimensional) framework is proposed for mapping various information communications services. The framework implies the important aspect of information technology (IT), or C&C (integration of computers and communications) technology as follows. The first axis is based upon the service classification made for BISDN-relevant services by the CCITT. This ‘communications’ axis covers not only the simple communication, or ‘space-wise information transfer’, but also messaging, retrieval etc. as ‘the combined space/time-wise information transfer’. The second axis represents ‘the multiplicity of media use’ in the human interface of information handling systems. The third axis represents the extent of ‘information processing/conversion’ or the level of computer technology penetration. In the latter part of this paper, the important interrelations between computer communications services and ISDN deployment are discussed using the scope of the above-proposed cubic map. The penetration of PMI (personal machine intelligence) to the same level as telephone set and television set, and the corresponding computer communications services requirements are identified as a fundamental driving force of (N)ISDN deployment.     

Price elasticity and the growth of computer spending

The price of computers is a key factor in explaining the growth of computer spending. However, it remains unclear whether the price elasticity of the demand for computers is constant over time. Findings on the pattern of price elasticity will have important implications in the study of information technology (IT) innovation diffusion. To test the hypothesis of dynamic price elasticity, we extend existing growth models to include a price factor with different elasticity specifications. Nested specifications of three growth models were tested using spending data from 1955 to 1984 adjusted by a quality price index for computers. The results indicate that three out of four competing models depict dynamic price elasticity over the investigated period. A similar pattern is also observed when the models are estimated using more recent data on mainframe computer spending. Our results underscore the dynamic behavior of price sensitivity in computer spending over time. They offer a new perspective to study innovation attributes and to examine their impacts empirically over time. Implications for information systems (IS) management and IT suppliers are also discussed     

Software workstations: one-stop shopping for utilities

To help electric utilities use their software more efficiently, the Electric Power Research Institute (EPRI) has been integrating groups of programs related to common engineering functions (for example, system grounding) into single packages. The institute calls these packages workstations, and each workstation allows a number of interdependent tasks to be performed much more efficiently. The original programs, which evolved one at a time over the years, rely on a wide variety of databases and interfaces, so users have had to develop input data for each program, and little of their experience in learning how to run one program carries over to learning another. In addition, some of the older programs were written for large mainframe computers, which are less user friendly and less accessible than the personal computes and engineering workstations now in widespread use. The benefits of this approach, which circumvents these difficulties, are discussed, and some of the packages available are described     

Compromising Electromagnetic Emanations of USB Mass Storage Devices

Universal Serial Bus (USB) has become the dominant Plug & Play interface for personal computers and continues to grow. Any digital communication source emits secondary or unwanted emissions, called compromising emanations, as they can be received and used to reconstruct the original transmitted information, thereby compromising the transmitted messages. This paper presents a number of experimental results regarding the USB communication between a personal computer and a USB memory device (USB bulk transfer) that has been performed in a specialized laboratory, and illustrates the capability of restoring information transmitted at bit level only from receiving the compromising radiation emitted by this communications bus. Comparative results for a shielded and unshielded device will also be illustrated. Finally, some TEMPEST protection methods are identified and presented against leakage of information through the compromising radiation of USB communication.

     

数据采集处理分析研究

计算机技术发展速度一日千里,在多个领域得到了广泛的应用.但从计算机的工作原理角度来说,计算机主要处理的是二进制数据,无论是存储还是计算应用,都是针对二进制数据进行的.那么计算机如何在多个领域产生作用,甚至在物联网、移动互联网络中发挥它的作用,就涉及了一个数据采集的工作环节.将外部的一些信号或者状态转换成计算机能够接收的数据,并进行相应计算处理,并最后转化成人们日常生活中需要的数据或者状态,这就是数据采集与数据处理发挥的作用.本文就数据采集、数据处理进行了相关的介绍与说明.     

DSM perspective: another point of view

Distributed shared memory computers (DSMs) have arrived (G. Bell, 1992; 1996) to challenge mainframes. DSMs scale to 128 processors with two to eight processor nodes. As shared memory multiprocessors (SMPs), DSMs provide a single system image and maintain a “shared everything” model. Large scale UNIX servers using the SMP architecture challenge mainframes in legacy use and applications. These have up to 64 processors and a more uniform memory access. In contrast, clusters both complement and compete with SMPs and DSMs, using a “shared nothing” model. Clusters built from commodity computers, switches, and operating system scale to almost arbitrary sizes at lower cost while trading off SMPs single system image. Clusters are required for high availability applications. Highest performance scientific computers use the cluster (or MPP) approach. High growth markets, e.g., Internet servers, online transmission processing (OLTP), and database systems can all use clusters. The mainframe future of DSM may be questionable because: small SMPs are not as cost effective unless built from commodity components; large SMPs can be built without the DSM approach; and clusters are a cost effective alternative for most applications to SMPs, including DSMs for a wide scaling range. Nevertheless, commercial DSMs are being introduced that compete with SMPs over a broad range