Assemblers for micro-computers

An assembler which provides facilities for programming in assembly language for the Intel 8080A micro-computer is described. This assembler is a single pass self-assembler and it requires a storage of 2K bytes. The assembler has been designed to be operated from a keyboard to develop programs in assembly language. It allows subroutine calls and nesting of subroutines to any depth. It flashes syntax errors, if any, while an instruction is being keyed in. The most important feature of the assembler is that it does not require costly peripherals such as floppy discs, cassette tapes, etc. It operates through a keyboard with letters (A-Z), Arabic numerals (0–9) and some special characters to accommodate mnemonics used in label, opcode and operand fields of programs in the assembly language. A display facility will be greatly helpful. In this paper, design and implementation details of assembler are presented. The authors have the view that assemblers for other micro-computers can be designed and implemented on similar lines. Though implementation may slightly differ from one micro-computer to another, the design details will mostly remain the same.     

Macro-Based Cross Assemblers

The problem of implementing cross assemblers by means of a macro expansion technique is addressed. Various problems caused by the implementation technique proper, as well as the target machine instruction set, are identified.     

Microsystems Microprogram Assemblers for Bit Slice Microprocessors

Designers of high-speed microprocessors need good software to help them construct the microprogram, but the seven bit-slice assemblers surveyed here remain essentially low level and even primitive.     

工作流管理规范综述

一、引言近几年来,工作流管理(Workflow Management)技术的研究与应用都取得了快速发展,许多软件开发商推出了自己的工作流产品。产品的繁多推动了技术应用的进步,使开发商可以把注意力集中到特殊的应用功能上,但同时也带来了技术的不兼容性,使得各种工作流产品之间、工作流系统同其他应用系统之间难以实现互操作。因此,必须要有一套规范化的工作流管理标准。工作流管理联盟(WfMC)正是在这样的形势下于1993年成立的。     

The Specification of Computer Graphics Systems

Specification techniques for computer graphics systems should emulate those employed in the specification of computer communication protocols and software systems, not the specification of programming languages.     

The Larch Family of Specification Languages

Larch specifications are two-tiered. Each one has a component written in an algebraic language and another tailored to a programming language.     

工作流过程定义规范

1 引言工作流过程定义规范定义了一个通用的交换格式,对业务流程进行形式化的说明。这种通用的交换格式,可支持不同产品间过程定义的传送。规范也内在地包括了开发环境和运行环境形式上的分离,这使得由建模工具生成的过程定义,能作为许多其它WFMS运行时产品的输入,符合了用户所要求的建模和产品运行的独立性。     

The Graphical Specification of Similarity Queries

Image databases will require a completely new organization due to the unstructured and ‘perceptual’ structure of the data they contain. We argue that similarity measures, rather than matching, will be the organizing principle of image databases. Similarity is a very elusive and complex judgment, and typical databases will have to rely on a number of different metrics to satisfy the different needs of their users. This poses the problem of how to combine different similarity measures in a coherent and intuitive way. In this paper we propose our solution, which is loosely based on ideas derived from fuzzy logic in that it uses the equivalent in the similarity domain of theand, orandnotoperations. The approach is much more general than that, however, and can be adapted to work with any operation that combines together similarity judgment.With this approach, a query can be described as a Directional Acyclic graph with certain properties. We analyse briefly the properties of this graph, and we present the interface we are developing to specify these queries.     

开放地理数据互操作规范综述

1 引言地理信息系统(Geographical Information Sys-tem,简称GIS)的研究,是当前世界上最热门、最具应用前景的课题之一。其研究所涉及的地理数据直接或间接地关联于地球表面的位置(时间,方位)。GIS广泛地应用于许多方面,如资源管理、土地规划、环境监测、防灾减灾、电力线架设、交通管理、城市导游、科研、教育和国防等。在我国国民经济的许多领域,GIS也有应用并日益发挥着越来越重要的作用。地理信息系统需要处理的地理数据,一般来说是非常巨大的,并且这些地理数据的类型种类也非常多。粗略地分,这些地理数据通常包括栅格数据、向量数据以及与时间有关的空间/时间数据等。随着卫星技术和全球定位系统技术的发展,使用地理信息系统的人员在迅速增加,数据的采集量也在迅速地增长。由于地理信息系统的复杂性,它所处理的地理数据的表述范围和表述形式都非常复杂。虽然许多获取、储备、处理、分析、观察地理数据的方法已经得到了发展,但这些数据之间的互操作往往是非常困难的。     

网络教育标准体系中的企业接口规范研究

企业接口规范(即TMS Enterprise）是IMS全球学习联合公司提出的一项最新的技术规范,在网络教育标准体系中占有重要的地位。它定义了一套适用于不同系统间数据交换的标准化信息结构,从而为标准化的数据绑定提供了基础,为不同软件开发商保证了独立开发系统的互操作性,并实现了基于异构系统间互操作上的流程建立及管理。详细介绍了企业接口标准的产生背景、涉及范围、技术支持,并具体讨论了该标准的实际应用。     

Specification

The specification and implementation of computational artefacts occurs throughout the discipline of computer science. Consequently, unpacking its nature should constitute one of the core areas of the philosophy of computer science. This paper presents a conceptual analysis of the central role of specification in the discipline.     

开放地理数据互操作规范综述

1 引言地理信息系统GIS的研究,是当前世界上最热门、最有应用前景的课题之一。它需要处理的地理数据,一般来说是非常巨大的,并且这些地理数据的类型种类也非常多。粗略地分,这些地理数据通常包括栅格数据、向量数据以及与时间有关的空间/时间数据等。随着卫星技术和全球定位系统技术发展,使用地理信息系统的人员在迅速增加,数据的采集量也在迅速     

Object—Z规格说明的SQL动画模拟

软件规格说明的确认在软件开发阶段占有举足轻重的地位。形式规格说明的动画模拟技术是一种规格说明的确认方法。本文研究了Obiect-Z规格说明的SQL动画模拟方法，设计了从Object-Z到SQL的转换规则，并提出了模块封装的思想，即用存储过程表示类、对象和模式等模块，用户通过调用执行存储过程确认规格说明是否满足其需求。     

一个支持规约获取的形式规约语言

该文介绍了形式规约语言LFC设计的一些主要方面，并通过例子说明了LFC的一些特色。形式规约语言LFC是为支持软件形式规约的获取工作而开发的。该语言以一种新的递归函数，即定义在上下文无关语言上的递归函数为基础，以上下文无关语言为数据类型，在语言级支持规约获取。LFC语言已被用作形式规约获取系统SAQ的一部分。使用表明，LFC是一个能力强、易使用的语言，适合软件形式规约获取之用，并且适合其它一些用途。     

The Formal Specification of Level la of GKS

In this paper the formal specification of a part of level la of GKS is given in the algebraic specification language OBJ. It shows that it is possible to produce a formal specification of a substantial part of GKS which is of manageable size and complexity specifying the appropriate level of abstraction of the system and using a suitable formal technique.     

通过CORBA规范访问数据库的方法和途径

文章提出了通过CORBA 规范访问数据库的途径，探讨了通过CORBA开发应用程序的基本步骤。     

Software Specification

Abstract

The notion of ‘specification’ is generally held to be crucial to the process of software production and the anchor point for the science of computing. It has, however, no simple, well-defined meaning. There are a variety of interpretations and usages of the term. This paper surveys the field of possibilities, both to display this varietal profusion, and to make the point that no one interpretation has a sound claim to be the best.     

Specification of iterators

Iterators are defined, and previously published methods for defining their meanings are outlined. It is shown how to use trace specifications to define a common form of iterator module (Alphard-style iterators). A form of specification for an iterator is shown which can capture the key differences between a set and a sequence at a few particular places in the specification. The trace specification of a sequence iterator is compared to an algebraic specification. It is concluded that the algebraic specification is possible but somewhat clumsier. Traces are used to give partial specifications of iterator construct that make sequences of calls on procedural parameters