Terminal Emulators

More FYI !!!

This post is about video terminals produced by Digital Equipment Corporation (DEC) from 1970 to 1995. The most famous of these is the VT100, a name which is recognized most often today as a setting in terminal emulation programs.

The real video terminals discussed on this web site ( http://vt100.net/ ) were dedicated devices which are connected to a computer (host) with a serial line. They usually consist of a screen and keyboard, with very little processing power and no local storage. Characters typed on the keyboard are transmitted to the host computer, and characters output from programs running on the host are sent to the terminal to be displayed on the screen. Why would we use devices this simple? Well, their simplicity makes them reliable. There is no operating system and no downloaded software, so they are pretty much impervious to user meddling and viruses. Before PCs put computing power on every desk, a central computer would support tens of users. Now that PCs are as powerful as old mainframes and can run capable multi-user operating systems (take a bow, Linux), there is a resurgence of interest in these low bandwidth, low cost and low maintenance devices.

AWESOME !!!

Terminal Emulators 2

From:
http://www.cs.utk.edu/~shuford/terminal_index.html
By ...Richard S. Shuford
Welcome to my Archive of Video-Terminal Information concerning character-cell video-display terminals, serial-line remote-graphics terminals, and software that emulates them. When I say character-cell terminal, I mean some keyboard-possessing device that is connected to a host computer by a serial cable and typically (if not exclusively) is used to display textual information arriving in the form of ASCII (or perhaps EBCDIC) characters. It is the thinnest possible thin client.

A serial-line remote-graphics-protocol terminal is also connected by a serial (usually RS-232-C) cable to a host, and it may display both ASCII text and graphics images sent to it by the remote host. Protocols for transmitting images include Tektronix vector graphics, DEC's ReGIS and Sixel protocols, and NAPLPS (North American Presentation-Level-Protocol Syntax).

X terminals in their own right are beyond the scope of this collection. An X terminal (such as one of these products still sold by NCD and Wyse Technology, or formerly made by Human Designed Systems/Neoware or Tektronix or Hewlett-Packard) speaks the X protocol, displays graphics in a completely bit-mapped fashion, and prefers to communicate over high-speed connections such as Ethernet. (Another variation on a thin-client is the "Network Computer".) I do, however, keep some small amount of X information here, but focusing on how the xterm application emulates a character-cell terminal.

Note that the information here does not include much coverage of the so-called "Terminal Services" functions in Microsoft Windows, which use the proprietary Remote Desktop Protocol (RDP). (As the computer industry has come to expect, adopting a Microsoft protocol forces you to buy Microsoft software and stay in lockstep with the Redmond upgrade cycle.)

This information started as a collection of discussion articles from Usenet newsgroups, especially comp.terminals but including other groups, but with some effort to organize the postings broadly by topic. However, resources from other sources have been added over time. The information in the collection varies in quality, and I personally wrote only a small part of it, but many people, who still have reason to use a terminal, have found it useful. There are no guarantees of applicability or fitness implied.

You should be able to access almost everything via HTTP. If you have trouble, let me know. If you possess information that you'd like to contribute to this collection, send me e-mail. Thanks.
...Richard S. Shuford

What is Gopher?

Just FYI !!

A type of Internet protocol from the early 1990's. Gopher presents a hierarchy of menus like a tree or graph of links. The links can be to documents, runnable programs, or other gopher menus arbitrarily far across the Internet.

From University of Minnesota March 1993
The Internet Gopher Protocol
(a distributed document search and retrieval protocol)

A simple protocol for burrowing through a TCP/IP internet. The Internet Gopher protocol and software follow a client-server model. This protocol assumes a reliable data stream and TCP is assumed. Gopher servers should listen on port 70 (port 70 is assigned to Internet Gopher by IANA). Documents reside on many autonomous servers on the Internet. Users run client software on their desktop systems, connecting to a server and sending the server a selector (a line of text, which may be empty) via a TCP connection at a well-known port. The server responds with a block of text terminated by a period on a line by itself and closes the connection. No state is retained by the server. Servers return either directory lists or documents. Each item in a directory is identified by a type (the kind of object the item is),user-visible name (used to browse and select from listings), an opaque selector string (typically containing a pathname used by the destination host to locate the desired object), a host name (which host to contact to obtain this item), and an IP port number (the port at which the server process listens for connections). The user only sees the user-visible name. The client software can locate and retrieve any item by the trio of selector, hostname, and port.

Quoted from ftp://ftp.isi.edu/in-notes/rfc1436.txt

More info:
http://www.savetz.com/yic/YIC03FI_20.html
gopher://gopher.floodgap.com/1/new/
http://gopher.floodgap.com/overbite/relevance.html

Happy New Year

Welcome to everyone at TMCC, especially all the staff, faculty, and students in the Computer Technology department!! I look forward to being of service to anyone who needs help.