Glossary

...of technical terms relevant to terminal emulation and file transfer. This was written in 2011 as a supplement to the Kermit 95 manual, but it is also useful for C-Kermit in general on all platforms.

ANSI

The American National Standards Organization, which issues standards for everything from screw threads to computer languages and character sets. In 1979 ANSI published standard X3.64, Additional Controls for Use with American National Standard Code for Information Interchange, which became the basis for the majority of today's terminal emulations, including the DEC VT100 terminal and its successors. Prior to X3.64, terminals were referred to as either full-screen (such as the IBM 3270 and IBM 5250 series) or ASCII (such as the Wyse 50/60, Televideo 9xx, Data General, Hazeltine, Honeywell, and many others). Terminals based upon the X3.64 standard became known as "ANSI" terminals. Like "ASCII terminals", they used the ASCII character-set, but unlike ASCII terminals, they also used a new well-defined and standard format for escape sequences which allowed a X3.64-compliant terminal to distinguish between commands and data unambiguously, even if it did not understand the commands. This allowed the X3.64 terminals to support a subset of the X3.64 standard and/or add extensions without breaking other terminals that implemented different subsets or extensions.

With the introduction of the IBM PC and MS-DOS in 1981 came a console device driver, ANSI.SYS, that implemented a very small portion of the X3.64 standard (11 commands and 3 extensions). This driver and the IBM PC BIOS and video architecture became the basis for the early PC Bulletin Board Systems. Users of these BBSs were told they needed an "ANSI" terminal, by which was meant an IBM PC running ANSI.SYS or an emulator for it, characterized by:

• The requirement for a fully transparent 8-bit data path (no parity)
• The use of color combined with IBM PC line- and box-drawing characters (CP437)
• The use of 25 screen lines (instead of the 24 lines on most commercial terminal)
• The use of PC-specific keys

As versions of UNIX and other operating systems were developed for the IBM PC they inherited similar requirements. Unfortunately, the developers of these new systems consistently called their terminal drivers "ANSI", even though each differed from the other, and this has led to a great deal of confusion for current users of their systems (SCO ANSI is a case in point).

Here is a list of all Kermit 95's terminal types that are based on the X3.64 standard. ANSI.SYS identifies a system based on the IBM PC console driver; VT identifies those terminals derived from the DEC VT terminals; and X3.64 are those terminals that most closely follow the original ANSI X3.64-1979 standard:

AIXTERM

The native terminal type for IBM AIX (X3.64)

ANSI-BBS

For accessing most BBSs (ANSI.SYS)

AT386

For accessing Unixware and Interactive UNIX systems (X3.64)

Avatar0+

A windowing system built on top of ANSI-BBS (ANSI.SYS)

BETERM

For accessing the BeBox (X3.64)

HFT - IBM High Function Terminal

Used to access IBM AIX and other systems (X3.64)

Linux

Used to access linux systems (VT)

QANSI

For accessing QNX systems (X3.64)

SCOANSI

For accessing SCO Xenix, SCO UNIX, SCO ODT, and SCO OpenServer. SCO refers to this terminal type as ANSI (X3.64)

SNI-97801

For accessing Siemens-Nixdorf Unix (Sinix) systems (X3.64)

VT100, VT102, VT220, VT320 (etc)

The DEC terminal family. Used to access VMS, Unix, and countless other systems. The most popular terminal in the world. (VT)

Wyse 370

A superset of the DEC VT320 terminal. (VT)

Only ANSI X3.64-1979 terminals are capable of processing APC command sequences.

ANSI X3.64-1979 was withdrawn and replaced by an international standard, ISO 6429.

APC

Application Program Command. The name of an escape sequence used in ANSI X3.64 emulations, in which the host computer can embed one or more commands for Kermit, the same commands that would be typed at the Kermit command prompt. An APC starts with ESC and Underscore and ends with ESC and backslash (ESC is Escape, ASCII character 27). K95/CKW do ignore these by default for safety, but they can be enabled by SET TERMINAL APC ON for running trusted host applications that depend on them.

API

Application Program Interface. The collection of subroutines or functions provided by the operating system or library, and their calling conventions. In Windows 95 and later Kermit 95 uses the Win32, Winsock, and TAPI APIs, among others.

ASCII

(1) The ANSI American Standard Code for Information Interchange, identical to the ISO 646 International Reference Version. Since 1967, ASCII has been the one-and-only universal character set, and will remain so for some time to come. ASCII has only 95 printable characters, and is therefore not suitable for representing languages other than English, Latin, Dutch, and a handful of others. Many schemes -- PC code pages, ISO Latin Alphabets, proprietary character sets of vendors like Hewlett Packard and Data General, etc -- have been devised to extend ASCII for other languages, but these are incompatible with each other, thus ASCII will remain the only universal character set for years to come, until and unless it replaced by a truly universal character set such as Unicode or ISO 10646. CLICK HERE for a table of the ASCII character set.

(2) In classifying computer systems, ASCII-based systems are those that use character sets based on ASCII for text files, as opposed to (say) IBM Mainframes, which use a different system called EBCDIC.

(3) In classifying terminal emulations, ASCII terminals are those, like Wyse 50, Wyse 60, Televideo, HPTERM, Data General, etc, that used the ASCII character-set and are not based upon the "ANSI" X3.64-1979 terminal specification.

(4) The "word" ASCII is sometimes used to mean plain text, as distinguished from binary. For example, "an ASCII file", "transfer in ASCII mode", etc.

BBS

Bulletin Board System. A multiuser computer system hosting chat rooms, software downloads, and the like. Typically accessed via dialup with ANSI terminal emulation, with a (usually colorful) text-mode menu-driven user interface.

CJK

The Chinese, Japanese, or Korean writing system.

Control Character

An ASCII character in the range 0 to 31, or ASCII character 127, contrasted with the printable, or graphic, characters in the range 32 to 126 (see the ASCII Table). Produced on an ASCII terminal by holding down the Ctrl key and typing the desired character. Standard 8-bit character sets such as ISO Latin-1 also have room for 32 additional control characters in the range 128 to 159, but names and uses of these characters are not specified by the Latin Alphabet standards. The 7-bit control characters are also known as the C0 set. The 8-bit control characters are also known as the C1 set. CLICK HERE for further details.

Console

In general, the keyboard and display with which a computer is controlled. On a PC, this is generally the PC's keyboard and screen. In Windows and OS/2, there are two kinds of programs: GUI (Graphical User Interface), and Console (text mode). Many people mistakenly believe that all Console-mode programs are 16-bit DOS programs, but that is not true. It is especially not true of Kermit 95. However, Console windows impose certain restrictions on the applications that use them -- even fully native 32-bit applications: the font and character-set choices are severely restricted, there is no convenient way to resize them, scroll bars can't be used by the application, etc.

CRLF

The two ASCII control characters, Carriage Return (13) and Line Feed (10), in sequence.

DDE

Dynamic Data Exchange, a feature of OS/2 and Windows allowing applications to exchange data. This is the sort of "standard" that changes about once a week, and/or replaced by succeeding generations such as VBX, OCX, OLE, COM, and other TLAs.

DNS

Internet Domain Name Service. An Internet service that translates a hostname, like kermit.columbia.edu, into a numeric Internet address, like 128.59.39.2.

EBCDIC

Extended Binary Coded Decimal Interchange Code. The text character set used on IBM mainframes and midrange systems. EBCDIC is entirely different from, and incompatible with, ASCII. All communications between IBM mainframes and the outside world involve ASCII/EBCDIC conversion.

Escape Sequence

A sequence of characters within a data stream that selects a certain function, for example, controlling the appearance of a terminal screen.

Graphic Character

A character that you can see, such as a letter, digit, or punctuation mark. A character that "puts ink on the page" or pixels on the screen. Exception: the Space character can not be seen but is considered a graphic character. Characters that are not graphics characters are control characters.

GUI

Graphical User Interface. There is a sharp distinction between GUI applications (such as Netscape, Internet Explorer, and the Kermit 95 Dialer) and Console applications (such as Kermit 95 itself) in terms of what resources (such as fonts, window-sizing controls, scroll bars, etc) they are allowed to access. In a future release, Kermit 95 will be available as a GUI Win32 application. There is as yet no firm date for this release. Check the Kermit 95 Website for news.

Host

In this manual, "host" is a shorthand way of referring to any computer or service that Kermit 95 can connect to via dialup, direct serial connection, or network. When discussing the Internet, "host" means a computer that has an Internet address and that can accept incoming connections.

HTML

HyperText Markup Language. The language of the World Wide Web, and the language in which this manual is written. You can see it in HTML form by choosing "View Source" in your browser. HTML files are plain text.

IP

Internet Protocol. The network layer of the Internet. An IP address lets one computer find another on the Internet.

IP Address

Internet Protocol Address. An IP address can be numeric, like 128.59.39.2, or symbolic, like kermit.columbia.edu. Symbolic host names are resolved by local host tables or network Domain Name Servers into numeric addresses. A numeric address includes four parts, separated by periods. Each part should contain only decimal digits with no leading 0's.

ISDN

Integrated Services Digital Network. A digital telephone service that allows simultaneous voice and data connections, and perhaps other services too.

ISO

The International Standardization Organization, which issues international standards in many areas, including computer technology. ISO standards relevant to Kermit 95 include:

ISO 646

7-bit character sets for many languages (national character sets)

ISO 6429

The international standard for terminal command sequences. This standard replaced ANSI X3.64-1979.

ISO 8859

8-bit character sets for many languages (the Latin Alphabets)

ISO 10646

The multibyte universal character set (UNICODE)

ISO 4873

Character set and escape sequence structure

ISO 2022

The use of escape sequences for character-set switching

ISP

Internet Service Provider. Most commonly, a company that provides you with an Internet presence through your modem and telephone line through a terminal server via PPP, allowing you to use a Web browser and to make ftp and telnet connections.

LAT

Local Area Transport, a proprietary Digital Equipment Corporation terminal oriented protocol used over Ethernet connections between terminal servers or PCs and VMS systems (or other Digital hosts, such as Ultrix or Digital UNIX). You can make LAT connections with Kermit 95 only if you have a separate LAT networking product installed, such as Digital PATHWORKS, or Meridian Technology SuperLAT. For more about LAT, CLICK HERE.

OEM

Original Equipment Manufacturer.

PBX

Private Branch Exchange. A private telephone system used within a company, school, building, etc, with a connection to the public telephone network that requires dialing a special prefix to "get an outside line".

Plain Text

The term "plain text" refers to information encoded in a character set such as ASCII, a PC code page, or Unicode that does not contain any additional application-specific markup, such as font information, boldfacing or italics, clickable links, photographs, etc. Plain text files are portable (except for any non-ASCII characters that might be used) among different platforms. They do not depend on a specific application to interpret them. Examples include command files, shell scripts, batch files, computer program source code, and (to an decreasing extent) most newsgroup postings and email messages. In Windows they may be created or edited using EDIT, NotePad, or WordPad. In OS/2, they may be created or edited using EDIT or ED. Files created by word processors such as Word Perfect or Microsoft Word are not plain text, at least not unless you go to extraordinary lengths to "export" them.

PARITY

This is explained HERE

PPP

Point to Point Protocol, used for connecting to a TCP/IP, IPX, NETBIOS, or other network through a dialup connection. More advanced than SLIP, and once in wide use by dialup Internet Service Providers (ISPs). In the typical scenario, your TCP/IP stack has a dialer that makes the connection to a terminal server at your ISP, which implements the PPP protocol. In some cases there is a text-mode login phase (often scripted so you are unaware of it) and then the connection switches to PPP mode. In other cases, the connection is always in PPP mode and a protocol such as CHAP is used within the PPP session for authentication. After authentication the PPP dialers are often crude and primitive, and users often ask if Kermit can be used instead. In OS/2, the answer is Yes, but in Windows it is No because Windows provides no way for an application like K95 to hand the connection, once made, over to the TCP/IP stack.

RFC

Request For Comments. What Internet standards are called (when they aren't called something else, like Internet Standards). RFCs are identified by number, for example RFC854 describes the very basic original Telnet protocol. CLICK HERE to visit the RFC archive.

SCOANSI

The form of ANSI X3.64 terminal emulation used by SCO operating systems including XENIX, UNIX, ODT, and OpenServer (SCO Unixware uses AT386). Note that SCO systems refer to this terminal type as ANSI (which outside of the SCO world refers to BBS ANSI, which is a different emulation), not SCOANSI. Therefore when making a TELNET connection from Kermit 95 to an SCO system, you must set Kermit 95's Terminal Type to SCOANSI, but you must also set its Telnet Terminal Type (the terminal name that is sent to the host during Telnet protocol negotiation) to ANSI.

SLIP

Serial Line Internet Protocol, used for connecting to a TCP/IP network through a dialup connection. Older than PPP, very simple, and dwindling in popularity.

SSH

Secure Shell. A public-key based security method.

SSL

Secure Sockets Layer. A public-key based security method. Also known as TLS. Unlike SSH, SSL/TLS includes provisions for revocation of compromised keys.

TAPI

Microsoft's Telephony Application Program Interface. The subsystem of Windows 95 and later and Windows NT 4.0 and later, through which modems are accessed. TAPI devices are listed and configured in the Modems entry of the Windows Control Panel. TAPI devices are an abstraction embodying both communication port and modem, and are referred to by their "long modem name" such as "US Robotics Courier V.34", rather than a device name like "COM1". Kemit 95 picks up all your TAPI modem configurations automatically, which means you don't have to configure them again in Kermit 95. For more about TAPI, CLICK HERE. TAPI is not available in OS/2.

TCP

Internet Transmission Control Protocol, which is used between two applications (typically client and server) across an IP connection.

TCP/IP

TCP over IP, the networking protocol combination that is the basis for the Internet, and over which most Internet applications (Telnet, FTP, Web browsers, etc) run.

Telnet

Short for Teletype Network (really!). The original Internet protocol for making interactive terminal connections from one computer to another.

TES

Terminal Emulation Services. TES-32 is a product of Interconnections / Attachmate allowing terminal connections to VMS hosts on Novell networks.

TGT

Kerberos Ticket Granting Ticket. A special ticket that lets its owner obtain additional tickets within the same realm. A TGT is obtained during the initial authentication process.

TLA

Three Letter Acronym. (The use of three letter acronyms to describe new computer APIs and services has gone to the extreme with Microsoft now using case-sensitive acronyms.) An XTLA is an "extended three-letter acronym", i.e. one having more than three letters.

TLS

Transport Layer Security. A public-key based security method.

Toggle

A key combination or mouse event that turns something off if it is on, and turns it on if it is off; e.g. "Alt-x toggles between the Terminal screen and the Command screen."

UCS

The Universal Character Set: Unicode (ISO 10646). UCS-2 is the simple (original) 16-bit two-byte-per-character representation of Unicode. Contrast with UTF-8.

Unicode

The Universal character set. A 16-bit (double-byte) character set encoding all of the world's major scripts. Unicode is gradually becoming the standard way of encoding text on the Web, in Windows, and eventually in most of the world's computer systems and databases. CLICK HERE to visit the Unicode Consortium website (if your computer is connected to the Internet).

UTF-8

Unicode 8-bit Transformation Format. A variable length encoding for Unicode in which ASCII is preserved unchanged. Thus ASCII is a proper subset of UTF-8, and all ASCII data is, by definition, also UTF-8 data. The same is not true of UCS-2 (q.v.), in which each ASCII character corresponds to a 16-bit UCS-2 character.

URL

Universal Resource Locator, used by Web browsers as the address of Web page or other resource. A typical URL is:

  http://www.kermit-project.org/

Win32

The 32-bit Application Program Program Interface (API) for 32-bit versions Microsoft Windows, including (at the writing) Windows 95 and later. A software program for Windows, such as Kermit 95, that uses only Win32 APIs is a native 32-bit Windows application, as opposed to (say) a 16-bit DOS application.

Winsock

A variation on the Berkeley Sockets API, the interface between an application program (like Kermit 95) and the TCP layer of the Internet, for use in Microsoft Windows.

WWW

World Wide Web.