ProfitPress Mega CDROM2 …eeware (MSDOS)(1992)(Eng)/ProfitPress-MegaCDROM2.B6I/MAGAZINE/MISC/MNJAN91.ZIP/GLOSS02

Text File | 1990-11-11 | 16.8 KB | 377 lines

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║                                  GLOSSARY                                ║
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MegaLink: The goal of this protocol is to design and implement a protocol that
     is fast, reliable and inexpensive. Megalink is a full streaming protocol.
     It uses a block of 512 bytes and a CRC-32 error correction to improve the
     performance.

Microcomputer: A small computer system, usually used by only one person.

Microprocessor:     An integrated circuit, or chip, that contains the circuits
     the computer needs to calculate and to communicate with the other parts of
     the system.

MNP: (Microcom Networking Protocol). A hardware-based modem error checking
     method. MNP converts asynchronous data to a synchronous bit stream,
     allowing the two framing bits normally required for each async character
     to be dispensed with.

Modem:    A device that permits the transmission of computer data over tele
     phone lines. Contraction of modulator-demodulator.



Modem7:   Modem7 is a relative of Xmodem. It passes the filename before
     starting the transfer. It is common on CP/M systems. This protocol allows
     more than one file to be sent at a time.

Monitor:  A device that displays computer input and output; usually used
     synonymously with display.

Monochrome Display Adapter (MDA):  A printed-circuit card in the system unit of
     a computer that controls the display. Shows text only at medium resolution
     in one color.

Monochrome:    A term used to describe a computer display capable of displaying
     one color (usually white, green, or amber).

Multicolor Graphics Array (MCGA):  A printed-circuit card in a computer that
     controls the display. MCGA shows both text and graphics at low to medium
     resolution in up to 256 colors, and is used in IBM PS/2 model computers.

Multilevel filing system:     A computer filing system that lets you define
     directories within other directories, creating a structure with many
     levels.  Also called a tree-structured or hierarchical filing system.

Network:  A group of computers that share resources, such as disk drives and
     printers.  The computers are linked together by printed-circuit cards,
     cables, and network software.

Null Modem:    A cable used to connect the serial ports of two computers in
     such a fashion that each thinks it is "talking" to a modem. Very fast
     serial data transfer may be acheived with a null modem.

Parity:   A computer data checking method using an extra bit in which the total
     number of binary 1's (or 0's) in a byte is always odd or always even;
     thus, in an odd parity scheme, every byte has eight bits of data and one
     parity bit. If using odd parity and the number of 1 bits comprising the
     byte of data is not odd, the 9th or parity bit is set to 1 to create the
     odd parity. In this way, a byte of data can be checked for accurate
     transmission by simply counting the bits for an odd parity indication.  If
     the count is ever even, an error is indicated.

Operating system:   A program that coordinates the operation of all parts of a
     computer system.

Output:   The result of a program's processing its input data.

Parallel communications: A communications technique that uses multiple inter
     connecting wires to send eight bits of a byte at once (in parallel).
Parallel port: The port to which the printer is usually attached.

Parameter:     A qualifier that you include with a command to define more
     specifically what you want DOS to do; also called an argument or an op-
     tion.

Parity:   An error-detection technique used for accuracy in data communica tion
                                                                           s.

Path name:     The portion of a file specification that defines the path to the
     file; can include a drive letter followed by a colon.

Path:     The list of directory names that defines the location of a directory
     to DOS.  The path statement goes into the AUTOEXEC.BAT file and follows
     the form: PATH=C:\;C:\DOS;C:\BAT;C:\WP;C:\DB;C:\UTIL

Pipe:     To direct the output of one command to be used as the input of
     another command. The pipe symbol DOS uses is the broken vertical bar (|).

Port:     The electrical connection through which the computer sends and
     receives data to and from devices or other computers.

Print queue:   The list of files to be printed by DOS; you create, examine, and
     modify the print queue with the Print command.







Printed-circuit card:    A thin, rectangular card or board, usually made of
     fiberglass or epoxy and coated with copper. A circuit is etched into the
     copper, and electronic devices, such as integrated circuits, are soldered
     to the circuit. Computer systems are made up of these cards.

Printer:  A device that produces images of text and graphics on paper.

PRN: Short for printer. The printer DOS uses unless instructed otherwise. Can
     refer to LPT1, LPT2, or LPT3.

Program:  A set of instructions for a computer.







Prompt:   A request displayed by the computer for you to provide some
     information or perform an action.

     One of the most useful things that can be done is put the command:

                                  prompt $p$g

     into the AUTOEXEC.BAT file.  This will tell the ANSI system to make the
     prompt indicate the name of the directory the drive is in.  Example:
     C:\DOS> or C:DOS\UTL>

Protocol: A set of conventions governing the format of messages to be exchanged
     within a communications system.

Puma:     This protocol has a full color display of transfer status. It can
     transfer up to 99 files in a single batch using dynamic block scaling for
     optimal data throughput. Like Zmodem, the resume option can continue an
     interrupted transfer.

Queue:    See print queue.

RAM disk: See virtual disk.

Read-only file:     A file whose read-only attribute is set so that its
     contents can be displayed and read, but not changed.

RAM: Short for Random Access Memory. The memory that DOS uses for programs and
     data; RAM content changes often while you use the computer, and is lost
     when the computer is turned off.

Redirection:   The process of causing a command or program to take its input
     from a file or device other than the keyboard (standard input), or of
     causing the output of a command or program to be sent to a file or device
     other than the display (standard output). The DOS redirection symbols are
     the greater-than (>) and less-than (<) signs.

Relaxed Xmodem:     This is the same as Xmodem except that it has a longer
     delay time. This is for use with remote services that can not tolerate
     strict timing during Xmodem transfers.

Replaceable parameter:   A symbolic reference, consisting of a percent sign
     followed by a one-digit number (such as %1), that can be included with
     commands in a batch file to refer to the parameters entered with the batch
     command.

Return key:    The Enter key.


ROM: Short for Read-Only Memory, the type of computer memory that is permanent
     ly recorded in hardware.  ROM contains instructions that help a computer
     carry out routine tasks, such as starting itself up. The contents of ROM
     cannot be changed and are not lost (non-volatile) when the computer is
     turned off.

Root directory:     The main directory that DOS creates on each disk; the top
     directory in a multilevel filing system.

RS-232 or RS-232C:  The standard computer hardware interface used for computer
     asynchronous communications connections.

SEAlink:  SEAlink is a advanced version of Xmodem developed by System Enhance
     ment Associates. It is a sliding window protocol.  SEAlink passes a name,
     size, and date of the transferring file and allows multiple files to be
     transfered.

Serial communications:   A communications technique that uses as few as two
     interconnecting wires to transmit bits one after the other.

Serial port:   The communications port (COM1, COM2, COM3, or COM4) to which
     devices, such as a modem or a serial printer, can be attached.


Serial:   A serial interface sends a stream of data bits separated by time or
     an electrical signal. For communications, serial interfaces often use a
     PROTOCOL, dividing the data stream into packets which may be checksummed
     to verify accuracy.

Shareware:     Software marketing system where the user gets to use the program
     for a period of time (usually 30 days) before they are expected to
     purchase (register) the program.  Shareware is most often less expensive
     than retail software and is often times just as good or even better.

Simplex:  Simplex transmission allows data to flow in one direction only (ex.,
     most parallel printer interfaces or the monitor).

Software: The programs that are used with a computer system.

Standard input:     The device from which a program reads its input unless the
     input is redirected. In normal DOS operation, standard input is the
     keyboard.

Standard output:    The device to which a program sends its output unless the
     output is redirected.  In normal DOS operation, standard output is the
     display.

Start/stop bits:    In serial, asynchronous transmission, start/stop bits
     indicate the beginning and end of each 7- or 8-bit data character.

Stop bit: A signal used in serial communications that marks the end of a
     character.

Sructured Query Language (SQL):    A query language developed by IBM that
     allows you to access your database.  This language can be used with a
     variety of database management products and can access databases on
     mainframes, minis, and PCs.

STY: A pseudo-teletype, which is a two-way pipeline with a job on one end and
     a fake keyboard-TTY on the other. Also, a standard program which provides
     a pipeline from its controlling TTY to a pseudo-teletype (and thence to
     another TTY, thereby providing a "sub-TTY").

Subdirectory:  A directory that is attached to a higher level directory.  For
     example, in the path statement: C:\DOS\UTL, the subdirectory, UTL is
     attached to the directory DOS.

Synchronous Data Transmission:     Data sent, usually in serial mode, with a
     clock pulse. No stop and start bits are needed.



System prompt: The characters DOS displays when it is at the command level
     (ready to accept a command); unless you specify otherwise, the system
     prompt consists of the letter of the current drive followed by a
     greater-than sign (for example, A>).

System program:     A program whose purpose is to control the operation of all
     or part of the computer system, such as managing the printer or interpret-
     ing commands.

Telecommunications: See communications.

Temporary file:     A file that DOS may create when told to redirect command
     input or output; deleted by DOS when the command is completed.

Telink:   This protocol is primarily found on Fido BBS systems. It is basically
     the Xmodem protocol using CRC checking with an extra block sent ahead of
     the file telling its name, size, and date. This protocol allows more than
     one file to be sent at a time.

Text editor :  A program that you use to create or change text files. Also
     called simply an editor.  The one supplied with the DOS system is named
     EDLIN.

Text file:     A file that you can read (contains ordinary letters, numbers,
     and punctuation marks).

Text:     Ordinary, readable characters, including the uppercase and lowercase
     letters of the alphabet, the numerals 0 through 9, and punctuation marks.

TSR: Terminate and Stay Ready program.  Also called memory resident or pop-up
     program.  A software program that stays in memory while you run other pro-
     grams.  To get the TSR to pop up on your screen, you simply press a
     designated "hotkey" combination like the one used to pop up MICRONEWS:
     e.g., Left-Shift - 5.

TTY: Terminal of the teletype variety, characterized by a noisy mechanical
     printer, a very limited character set, and poor print quality. Usage:
     antiquated (like the TTY's themselves). Sometimes used to refer to any
     terminal at all; sometimes used to refer to the particular terminal
     controlling a job.

Update:   To change a file, creating a new (or updated) version.

Video Graphics Array (VGA):   A printed-circuit card in the computer that
     controls the display. VGA shows both text and graphics at medium to high
     resolution in up to 256 colors; used in IBM PS/2 model computers.



V.32:     A CCITT specification defining a family of FULL DUPLEX modems using 5
     digital bits for each carrier change at a 2400 baud rate. While this
     produces a raw throughput of 12,000 bps, 1 out of 5 bits is used for error
     correction, reducing throughput to 9,600 bps.

Virtual disk:  A portion of the computer's Random Access Memory reserved for
     use as a simulated disk drive. Also called an electronic or RAM disk.
     Unless saved on a physical disk, the contents of a virtual disk are lost
     (volatile) when the computer is turned off.

Volume label:  An 11-character identifying name you can assign to a disk.

Wildcard character: A special character that, like the wild card in a card
     game, can be used to represent any other character.  DOS recognizes two
     wildcard characters: the question mark (?), which can represent any single
     character, and the asterisk (*), which can represent more than one
     character.

Write-protect: To cover the small notch or opening on a diskette so that new or
     changed information cannot be written onto the diskette.








WYSIWYG:  What you see is what you get (pronounced "wiz-ee-wig").  A desktop
     publishing phrease referring to the match between interfaces and printers.
     It means that what you see on the computer screen is what you'll get on
     the printed copy.

X.25:     A CCITT standard that describes how data is handled in a packet
     switched network.

Xmodem-1K:     This is a variation of Xmodem which uses blocks that may be 128
     bytes or  1024 bytes in size. Most communications packages support this
     protocol   by allow 1K block in Xmodem protocol. Some BBS softwares refer
     to Xmodem-1K as Ymodem. Ymodem sends the name, size and date of the file
     but Xmodem-1K does not. If the filename 'UNKNOWN.$$$' shows in the
     transfer window during a Ymodem transfer, it is likely that the BBS
     software is using Xmodem-1K, in this case, you should select Xmodem
     protocol.


Xmodem:   A protocol for transferring blocks of data via modem with a high
     degree of accuracy. Developed by Ward Christensen for CP/M systems in the
     late '70s and now the basic standard for error-detected data transfer.
     Xmodem is  the most popular protocol in use today, but it is slowly being
     replaced by quicker and more reliable protocols. Error checking is a
     checksum or a the Cyclic Redundancy Check. The Xmodem protocol requires a
     setup of no parity, 8 data bits, and 1 stop bit. While sending a file,
     Xmodem always uses a 128 byte block.

XON/XOFF: Protocol for controlling the flow of data. If you dial into a
     timesharing system in which many users simultaneously use the same comput-
     er and if the system is about to overflow, it will send an XOFF character
     to your computer. The XON character will be sent to you when the system is
     ready to receive again.

Ymodem-G: This protocol is a variation on Batch Ymodem. It achieves very high
     transfer rates by sending blocks one after another without waiting for
     acknowledgement. This however means that an error-free link such as an
     error-correcting modem or null modem cable between two computers is
     needed. If an error is detected by the receiver, the transfer is aborted.
     It allows transferring multiple files.

Ymodem:   This is a variation of the Xmodem which uses blocks that may be 128
     bytes or 1024 bytes in size and keeps the correct name, size, and date.











Zmodem:   This advanced protocol is both fast and reliable, and offers many
     features. Zmodem can transfer a group of files in one batch, while keeping
     the exact file size and dates. Zmodem detects and recovers from errors
     quickly. The Zmodem Recovery feature can resume an interrupted transfer.