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LeechZmodem
LeechModem was a BBS file transfer protocol client. LeechModem was compatible with protocols like XMODEM (and YMODEM), but it would mischievously NAK the last packet and then abort the file transfer. The user had successfully downloaded the file, but the BBS would mistakenly not count the aborted file transfer against the user's download quota. The user would need to know and input the filesize before the transfer so the client would know when to abort. Leech-modem was designed by Sam Brown. Leech ZMODEM was suggested by Sam Brown but written by a long lost friend in Atlanta, GA. Leech ZMODEM was a LeechModem variant that was compatible with the faster ZMODEM streaming file-transfer protocol. Subsequent versions of Leech ZMODEM were authored by Sam Brown. LeechModem was used successfully for 2-3 years by a small group of people centered in the 408 area code and 203 area code. It was not until the LeechModem software was leaked that it was discovered and counter-measures were b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ZMODEM
ZMODEM is an inline file transfer protocol developed by Chuck Forsberg in 1986, in a project funded by Telenet in order to improve file transfers on their X.25 network. In addition to dramatically improved performance compared to older protocols, ZMODEM offered restartable transfers, auto-start by the sender, an expanded 32-bit CRC, and control character quoting supporting 8-bit clean transfers, allowing it to be used on networks that would not pass control characters. In contrast to most transfer protocols developed for bulletin board systems (BBSs), ZMODEM was not directly based on, nor compatible with, the seminal XMODEM. Many variants of XMODEM had been developed in order to address one or more of its shortcomings, and most remained backward compatible and would successfully complete transfers with "classic" XMODEM implementations. This list includes Forsberg's own YMODEM. ZMODEM eschewed backward compatibility in favor of producing a radically improved protocol. It perfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bulletin Board System
A bulletin board system (BBS), also called computer bulletin board service (CBBS), is a computer server running software that allows users to connect to the system using a terminal program. Once logged in, the user can perform functions such as uploading and downloading software and data, reading news and bulletins, and exchanging messages with other users through public message boards and sometimes via direct chatting. In the early 1980s, message networks such as FidoNet were developed to provide services such as NetMail, which is similar to internet-based email. Many BBSes also offer online games in which users can compete with each other. BBSes with multiple phone lines often provide chat rooms, allowing users to interact with each other. Bulletin board systems were in many ways a precursor to the modern form of the World Wide Web, social networks, and other aspects of the Internet. Low-cost, high-performance asynchronous modems drove the use of online services and BBSes t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protocols For File Transfer
This article lists communication protocols that are designed for file transfer over a telecommunications network. Protocols for shared resource, shared file systems—such as 9P (protocol), 9P and the Network File System—are beyond the scope of this article, as are file synchronization protocols. Protocols for packet-switched networks A packet-switched network Data transmission, transmits data that is divided into units called ''Network packet, packets''. A packet comprises a Header (computing), header (which describes the packet) and a Payload (computing), payload (the data). The Internet is a packet-switched network, and most of the protocols in this list are designed for its protocol stack, the IP protocol suite. They use one of two transport layer protocols: the Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP). In the tables below, the "Transport" column indicates which Communications protocols, protocol(s) the transfer protocol uses at the transp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
YMODEM
YMODEM is a file transfer protocol used between microcomputers connected together using modems. It was primarily used to transfer files to and from bulletin board systems. YMODEM was developed by Chuck Forsberg as an expansion of XMODEM and was first implemented in his CP/M YAM program. Initially also known as YAM, it was formally given the name "YMODEM" in 1985 by Ward Christensen, author of the original XMODEM. YMODEM extended XMODEM in three ways, combining features found in other extended XMODEM varieties. Like XMODEM-CRC, YMODEM replaced the 8-bit checksum with a 16-bit cyclic redundancy check (CRC), but made it the default form of correction instead of optional. From TeLink it added the "block 0" header that sent the filename and size, which allowed batch transfers (multiple files in a single session) and eliminated the need to add padding at the end of the file. Finally, YMODEM allowed the block size to be increased from the original 128 bytes of data to 1024, as in XMODEM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 408
Area codes 408 and 669 are telephone area codes in the North American Numbering Plan (NANP) in the U.S. state of California. The numbering plan area comprises most of Santa Clara County and Northern Santa Cruz County, and includes Gilroy, Morgan Hill, Saratoga, Los Gatos, Monte Sereno, Milpitas, Sunnyvale, Santa Clara, Cupertino, Campbell, and San Jose. Area code 408 was split from area code 415 in 1959, and area code 669 was assigned to the same numbering plan area in an overlay plan in 2012. History As of 1950, the central and northern regions of California had been divided into two numbering plan areas (NPAs) along a south–north boundary, with area code 415 assigned to the coastal stretch, and 916 for the mountainous region in the east. Area code 408 was split from numbering plan area 415 in a flash-cut (without permissive dialing period) on March 1, 1959. On July 11, 1998, area code 408 was split, producing area code 831 for the counties of Santa Cruz, Monterey, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Area Code 203
Area codes 203 and 475 are telephone area codes in the North American Numbering Plan The North American Numbering Plan (NANP) is a telephone numbering plan for twenty-five regions in twenty countries, primarily in North America and the Caribbean. This group is historically known as World Zone 1 and has the international callin ... (NANP) for the southwestern part of the U.S. state of Connecticut. The numbering plan area (NPA) is mostly coextensive with the Connecticut portion of the New York metropolitan area, and comprises most of Fairfield County, Connecticut, Fairfield County, all of New Haven County, Connecticut, New Haven County, and a small portion of Litchfield County, Connecticut, Litchfield County. When the American Telephone and Telegraph Company (AT&T) established the first nationwide telephone numbering plan, numbering plan in 1947, Connecticut received only a single area code, 203, of the 86 original North American area codes. On August 28, 1995 the state was d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leech (computing)
In computing and specifically in Internet slang, a leech is one who benefits, usually deliberately, from others' information or effort but does not offer anything in return, or makes only token offerings in an attempt to avoid being called a leech. In economics, this type of behavior is called "free riding" and is associated with the free rider problem. The term originated in the bulletin board system era, when it referred to users that would download files and upload nothing in return. Depending on context, leeching does not necessarily refer to ''illegal'' use of computer resources, but often instead to ''greedy'' use according to etiquette: to wit, using too much of what is freely given without contributing a reasonable amount back to the community that provides it. The word is also used without any pejorative connotations, simply meaning to download large sets of information: for example the offline readerbr>Leech the Usenet newsreader NewsLeecher, the audio recording softw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
