...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.
- 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
With the introduction of the IBM PC and MS-DOS in 1981 came a
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:
- The native terminal type for IBM AIX (X3.64)
- For accessing most BBSs (ANSI.SYS)
- For accessing Unixware and Interactive UNIX systems (X3.64)
- A windowing system built on top of ANSI-BBS (ANSI.SYS)
- For accessing the BeBox (X3.64)
- HFT - IBM High Function Terminal
- Used to access IBM AIX and other systems (X3.64)
- Used to access linux systems (VT)
- For accessing QNX systems (X3.64)
- For accessing SCO Xenix, SCO UNIX, SCO ODT, and SCO OpenServer. SCO
refers to this terminal type as ANSI (X3.64)
- For accessing Siemens-Nixdorf Unix (Sinix) systems (X3.64)
- VT100, VT102, VT220, VT320
- The DEC terminal family. Used to access VMS, Unix, and almost every
other system. 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,
- 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).
- 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.
- (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.
- 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.
- 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.
- 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.
- The two ASCII control characters, Carriage Return (13)
and Line Feed (10), in sequence.
- 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.
- Internet Domain Name Service. An Internet service that translates a
hostname, like kermit.columbia.edu, into a numeric Internet address,
- 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
- 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
- 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.
- 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
- 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
22.214.171.124, 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
- Integrated Services Digital Network. A digital telephone service that
allows simultaneous voice and data connections, and perhaps other services
- 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
- 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.
- 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.
- Original Equipment Manufacturer.
- 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.
- This is explained HERE
- 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.
- 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
CLICK HERE to visit the RFC archive.
- 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.
- Serial Line Internet Protocol, used for connecting to a TCP/IP network
through a dialup connection. Older than PPP, very simple, and dwindling in
- Secure Shell. A public-key based security method.
- Secure Sockets Layer. A public-key based security method. Also known
as TLS. Unlike SSH, SSL/TLS includes provisions for revocation of
- 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
CLICK HERE. TAPI is not available in OS/2.
- Internet Transmission Control Protocol, which is used between two
applications (typically client and server) across an IP connection.
- 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.
- Short for Teletype Network (really!). The original Internet protocol
for making interactive terminal connections from one computer to another.
- Terminal Emulation Services. TES-32 is a product of Interconnections /
Attachmate allowing terminal connections to VMS hosts on Novell networks.
- 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.
- 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.
- Transport Layer Security. A public-key based security method.
- 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."
- 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.
- 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).
- 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.
- Universal Resource Locator, used by Web browsers as the address of Web
page or other resource. A typical URL is:
- 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
- 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.
- World Wide Web.