ManaGeR
Encyclopedia
ManaGeR or MGR was an early windowing system
originally designed and developed for Sun computers in 1984 by Stephen A. Uhler, then at Bellcore.
MGR featured overlapped, asynchronous windows and an applications interface that was both machine and network independent.
Each MGR window had support for both character terminal operations as well as basic graphics operations. It was controlled by mousing pop-up menus, by keyboard interaction, and by escape sequences written on pseudo-terminals
by client software.
The system was presented at the USENIX
Fourth Computer Graphics Workshop in 1987 as "MGR - a Window System for UNIX". The entire MGR source code was posted to the comp.sources.unix Usenet
newsgroup, Volume 17, Issue 1, in January 1989.
All these features worked equally well if the client program was executing on the same computer as the MGR server or if the client was executed on a remote computer. The type of connection was insignificant. You could use telnet over TCP/IP or a modem dial-up connection equally well, for instance.
External programs such as Stephen Uhler's own MTX and Howard Chu's rmgr made it possible to multiplex several windows over a single connection to a remote host, even using a normal modem dial-up connection.
A later feature, $HOME MOVIE, made it possible to record user interaction for later display.
, Coherent
, Linux
, FreeBSD
and VSTa
.
Windowing system
A windowing system is a component of a graphical user interface , and more specifically of a desktop environment, which supports the implementation of window managers, and provides basic support for graphics hardware, pointing devices such as mice, and keyboards...
originally designed and developed for Sun computers in 1984 by Stephen A. Uhler, then at Bellcore.
MGR featured overlapped, asynchronous windows and an applications interface that was both machine and network independent.
Each MGR window had support for both character terminal operations as well as basic graphics operations. It was controlled by mousing pop-up menus, by keyboard interaction, and by escape sequences written on pseudo-terminals
Pseudo terminal
In some operating systems, including Unix, a pseudo terminal is a pseudo-device pair that provides a text terminal interface without an associated device, such as a virtual console, computer terminal or serial port...
by client software.
The system was presented at the USENIX
USENIX
-External links:* *...
Fourth Computer Graphics Workshop in 1987 as "MGR - a Window System for UNIX". The entire MGR source code was posted to the comp.sources.unix Usenet
Usenet
Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
newsgroup, Volume 17, Issue 1, in January 1989.
Features
MGR provided each client window with:- termcapTermcapTermcap is a software library and database used on Unix-like computers. It enables programs to use display computer terminals in a device-independent manner, which greatly simplifies the process of writing portable text mode applications...
-style terminal control functions, graphics primitives such as line and circle drawing; - facilities for manipulating bitmaps, fonts, iconsIcon (computing)A computer icon is a pictogram displayed on a computer screen and used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive representation of a software tool, function or a data file accessible on the system. It functions as an...
, and pop-up menusMenu (computing)In computing and telecommunications, a menu is a list of commands presented to an operator by a computer or communications system. A menu is used in contrast to a command-line interface, where instructions to the computer are given in the form of commands .Choices given from a menu may be selected...
; - commands to reshape and position windows; and a message passingMessage passingMessage passing in computer science is a form of communication used in parallel computing, object-oriented programming, and interprocess communication. In this model, processes or objects can send and receive messages to other processes...
facility enabling client programs to rendezvous and exchange messages. Client programs may ask to be informed when a change in the window system occurs, such as a reshaped window, a pushed mouseMouse (computing)In computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...
buttonButtonIn modern clothing and fashion design, a button is a small fastener, most commonly made of plastic, but also frequently of seashell, which secures two pieces of fabric together. In archaeology, a button can be a significant artifact. In the applied arts and in craft, a button can be an example of...
, or a message sent from another client program. These changes are called eventsEvent-driven programmingIn computer programming, event-driven programming or event-based programming is a programming paradigm in which the flow of the program is determined by events—i.e., sensor outputs or user actions or messages from other programs or threads.Event-driven programming can also be defined as an...
. MGR notifies a client program of an event by sending it an ASCIIASCIIThe American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...
character string in a format specified by the client program. Existing applicationsApplication softwareApplication software, also known as an application or an "app", is computer software designed to help the user to perform specific tasks. Examples include enterprise software, accounting software, office suites, graphics software and media players. Many application programs deal principally with...
can be integrated into the windowing environment without modification by having MGR imitate keystrokes in response to user defined menu selections or other events.
All these features worked equally well if the client program was executing on the same computer as the MGR server or if the client was executed on a remote computer. The type of connection was insignificant. You could use telnet over TCP/IP or a modem dial-up connection equally well, for instance.
External programs such as Stephen Uhler's own MTX and Howard Chu's rmgr made it possible to multiplex several windows over a single connection to a remote host, even using a normal modem dial-up connection.
A later feature, $HOME MOVIE, made it possible to record user interaction for later display.
Ports
MGR ran on at least these systems: SunOS on Sun workstations, the original development platform, Macintosh, Unix System V on the AT&T UnixPC, Ultrix on DECstation 3100, MiNT on Atari ST, OS-9OS-9
OS-9 is a family of real-time, process-based, multitasking, multi-user, Unix-like operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It is currently owned by RadiSys Corporation....
, Coherent
Coherent (operating system)
The Coherent operating system was a Version 7 Unix clone by the now-defunct Mark Williams Company, originally produced for the PDP-11 in 1980. A port was introduced in 1983 as the first Unix-like system for IBM PC compatible computers....
, Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
, FreeBSD
FreeBSD
FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...
and VSTa
VSTa
VSTa was an operating system with a microkernel architecture, with all device drivers and file systems residing in userspace mode. It is mostly POSIX compliant, except when POSIX compatibility got in the way of extensibility and modularity. It was conceptually inspired by QNX and Plan 9. Written...
.
See also
- History of the graphical user interfaceHistory of the graphical user interfaceThe graphical user interface, understood as the use of graphic icons and a pointing device to control a computer, has a four decade history of incremental refinements built on some constant core principles...
- Carsten Emde: "The MGR window manager", OS-9 International, I/1993, pp. 18.
- Carsten Emde: "Embedded Image Processing Under OS-9/MGR", The VITA Journal - June, 1996.