Berkeley Unix Research Articles

A distributed programs monitor for berkeley UNIX

AbstractWriting and debugging distributed programs can be difficult. When a program is working, it can be difficult to achieve reasonable execution performance. A major cause of these difficulties is a lack of tools for the programmer. We use a model of distributed computation and measurement to implement a program monitoring system for programs running on the Berkeley UNIX 4.2BSD operating system. The model of distributed computation describes the activities of the processes within a distributed program in terms of computation (internal events) and communication (external events). The measurement model focuses on external events and separates the detection of external events, event record selection and data analysis. The implementation of the measurement tools involved changes to the Berkeley UNIX kernel, and the addition of daemon processes to allow the monitoring activity to take place across machine boundaries. A user interface has also been implemented.

Implementation of an interpreter for abstract equations

AbstractThis paper summarizes a project whose goal is the implementation of a useful interpreter for abstract equations that is absolutely faithful to the logical semantics of equations. The interpreter was first distributed to Berkeley UNIX VAX sites in May 1983. The main novelties of the interpreter are strict adherence to semantics based on logical consequences, ‘lazy’ (outermost) evaluation applied uniformly, an implementation based on table‐driven pattern matching, with no run‐time penalty for large sets of equations, and strict separation of syntactic and semantic processing, so that different syntaxes may be used for different problems.

General-purpose crossassembler for 8-bit microprocessors

A study of microprocessor instruction sets is presented. The techniques devised to implement a general-purpose crossassembler for 8-bit machines are described. The program has been implemented on a VAX-11/750 under Berkeley Unix 4.1 BSD.

Wsh—a new command interpreter for unix

AbstractWSH is a window managing command language interpreter (shell) for the UNIX operating system. This interface increases a user's power to communicate with UNIX by providing a process management environment based on an integrated virtual terminal‐shell design. Unlike conventional shells, WSH affords its user the ability to monitor and communicate with multiple processes within a single display context. Windows represent virtual terminals in the WSH design, and as such are device‐independent abstractions of real terminals. Since the design of the virtual terminal environment is based on UNIX's TERMCAP terminal database facility, WSH is portable across all versions of UNM supporting this feature. WSH requires neither alteration of existing UNIX facilities nor special display devices. The current implementation runs on a Digital VAX 11/780 under Berkeley UNIX 4.1 environment.

An icon-driven end-user interface to UNIX

Some aspects of the end user interface are considered and an icon-driven system recently developed by us, called UNICON (after “UNIX-icon”), is described. UNI-CON uses colour graphic icons, instead of commands, as the means by which a user and operating system interact. It is designed, as far as is possible, to be independent of graphics devices and to be portable between different operating systems. The current version, which runs under Berkeley UNIX ™ 4·1 bsd, is an implementation of a minimum kernel of filestore management commands relevant to all applications. Various problems and potential applications highlighted during the project are also discussed.

The Poe language-based editor project

Editor Allan Poe (Pascal Oriented Editor) is a full-screen language-based editor (LBE) that knows the syntactic and semantic rules of Pascal. It is the first step in development of a comprehensive Pascal program development environment. Poe's design began in 1979; version 1 is currently operational on Vax 11s under Berkeley Unix and on HP 9800-series personal workstations. Poe is written in Pascal, and is designed to be readily transportable to new machines. An editor-generating system called Poegen is operational, and much of the language-specific character of Poe is table-driven and retargetable.

The Poe language-based editor project

Editor Allan Poe (Pascal Oriented Editor) is a full-screen language-based editor (LBE) that knows the syntactic and semantic rules of Pascal. It is the first step in development of a comprehensive Pascal program development environment. Poe's design began in 1979; version 1 is currently operational on Vax 11s under Berkeley Unix and on HP 9800-series personal workstations. Poe is written in Pascal, and is designed to be readily transportable to new machines. An editor-generating system called Poegen is operational, and much of the language-specific character of Poe is table-driven and retargetable.

IDEOSY

IDEOSY is an experiment in the use of a formal semantics as the basis for a programming system and in use of an ideographic language as the primary means of user-computer communication. The important characteristics of our system are that it uses an ideographic syntax, has a syntax-directed editor, supports the definition of various equivalence properties and the proofs of such equivalence, and has an interpreter. It currently runs on Apollo workstations and on VAXes running Berkeley UNIX@ using any of a variety of high-resolution color displays. Our formalism is based on Milner's Calculus of Communicating Systems ( CCS ) [1]. We have found CCS to be a convenient formalism for describing programs and have even used it for describing the UNIX operating system [2]. Its algebraic properties are very useful for building descriptions out of components and for proving the equivalence of descriptions. Since CCS is an operational semantics, we may directly interpret descriptions written in CCS.

IDEOSY

IDEOSY is an experiment in the use of a formal semantics as the basis for a programming system and in use of an ideographic language as the primary means of user-computer communication. The important characteristics of our system are that it uses an ideographic syntax, has a syntax-directed editor, supports the definition of various equivalence properties and the proofs of such equivalence, and has an interpreter. It currently runs on Apollo workstations and on VAXes running Berkeley UNIX@ using any of a variety of high-resolution color displays. Our formalism is based on Milner's Calculus of Communicating Systems ( CCS ) [1]. We have found CCS to be a convenient formalism for describing programs and have even used it for describing the UNIX operating system [2]. Its algebraic properties are very useful for building descriptions out of components and for proving the equivalence of descriptions. Since CCS is an operational semantics, we may directly interpret descriptions written in CCS.

GKS for imaging

By adopting the Graphical Kernel System (GKS), groups who manipulate pixelated images can take advantage of device independent graphics without giving up the functions which have traditionally been hardware dependent. Most of these functions, including image I/O, zoom, pan, lookup table manipulation, and cursor reading, are supported within GKS; several other functions, such as the use of multiple image planes and multiple look up tables, are accomodated by the GKS Escape and the Generalized Drawing Primitive (GDP). Because GKS has powerful inquire capabilities, it's possible to tightly customize applications code to a particular hardware display device. The inquire functions also can be used by an applications program to determine the hardware display size and thus avoid resampling of a pixelated image. GKS thoroughly separates applications programs from device- dependencies; however, device drivers must still be written. The time and effort of writing device drivers can be largely eliminated by using a single programmable device driver, which is tailored to each device by a GRAPHCAP configuration file, in much the same way as TERMCAP is used by Berkeley Unix implementations.