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C-MODEM
C-Modem is a protocol driver developed by Lavio Pareschi (Rio de Janeiro) in 1989 that functions similarly to ZMODEM. Features C-Modem has a crash recovery feature. If a transmission is interrupted, the partially received file is saved with the extension .BAD. Upon reconnection, the transmission resumes. The protocol dynamically adjusts the size of data blocks between cyclic redundancy checks based on transmission speed and error rates. Block sizes can range from 32 to 4096 bytes. C-Modem also supports full duplex A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow ... communication. References External links C-Modem 1.1 program C-Modem documentation BBS file transfer protocols {{software-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rio De Janeiro
Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the Americas, sixth-most-populous city in the Americas. Founded in 1565 by the Portuguese people, Portuguese, the city was initially the seat of the Captaincy of Rio de Janeiro, a domain of the Portuguese Empire. In 1763, it became the capital of the State of Brazil, a List of states of the Portuguese Empire, state of the Portuguese Empire. In 1808, when the Transfer of the Portuguese Court to Brazil, Portuguese Royal Court moved to Brazil, Rio de Janeiro became the seat of the court of Queen Maria I of Portugal. She subsequently, under the leadership of her son the prince regent John VI of Portugal, raised Brazil to the dignity of a kingdom, within the United Kingdom of Portugal, Brazil and the Algarves, United Kingdom of Portugal, Brazil, and Algar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crash-only Software
A crash-only software is a computer program that handle failures by simply restarting, without attempting any sophisticated recovery. Correctly written components of crash-only software can microreboot to a known-good state without the help of a user. Since failure-handling and normal startup use the same methods, this can increase the chance that bugs in failure-handling code will be noticed, except when there are leftover artifacts, such as data corruption from a severe failure, that don't occur during normal startup. Crash-only software also has benefits for end-users. All too often, applications do not save their data and settings while running, only at the end of their use. For example, word processors usually save settings when they are closed. A crash-only application is designed to save all changed user settings soon after they are changed, so that the persistent state matches that of the running machine. No matter how an application terminates (be it a clean close or t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Block (data Storage)
In computing (specifically data transmission and data storage), a block, sometimes called a physical record, is a sequence of bytes or bits, usually containing some whole number of records, having a fixed length; a ''block size''. Data thus structured are said to be ''blocked''. The process of putting data into blocks is called ''blocking'', while ''deblocking'' is the process of extracting data from blocks. Blocked data is normally stored in a data buffer, and read or written a whole block at a time. Blocking reduces the overhead and speeds up the handling of the data stream. For some devices, such as magnetic tape and CKD disk devices, blocking reduces the amount of external storage required for the data. Blocking is almost universally employed when storing data to 9-track magnetic tape, NAND flash memory, and rotating media such as floppy disks, hard disks, and optical discs. Most file systems are based on a block device, which is a level of abstraction for the hard ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Redundancy Check
A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to digital data. Blocks of data entering these systems get a short ''check value'' attached, based on the remainder of a polynomial division of their contents. On retrieval, the calculation is repeated and, in the event the check values do not match, corrective action can be taken against data corruption. CRCs can be used for error correction (see bitfilters). CRCs are so called because the ''check'' (data verification) value is a ''redundancy'' (it expands the message without adding information) and the algorithm is based on ''cyclic'' codes. CRCs are popular because they are simple to implement in binary hardware, easy to analyze mathematically, and particularly good at detecting common errors caused by noise in transmission channels. Because the check value has a fixed length, the function that generates it is occasionally used as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duplex (telecommunications)
A duplex communication system is a point-to-point system composed of two or more connected parties or devices that can communicate with one another in both directions. Duplex systems are employed in many communications networks, either to allow for simultaneous communication in both directions between two connected parties or to provide a reverse path for the monitoring and remote adjustment of equipment in the field. There are two types of duplex communication systems: full-duplex (FDX) and half-duplex (HDX). In a full-duplex system, both parties can communicate with each other simultaneously. An example of a full-duplex device is plain old telephone service; the parties at both ends of a call can speak and be heard by the other party simultaneously. The earphone reproduces the speech of the remote party as the microphone transmits the speech of the local party. There is a two-way communication channel between them, or more strictly speaking, there are two communication channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
