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BinHex
BinHex, originally short for "binary-to-hexadecimal", is a binary-to-text encoding system which was used on the classic Mac OS for sending binary files over email. BinHexed files take up more space than the original files, but avoid data corruption by software that is not 8-bit clean. History TRS-80 BinHex BinHex was originally written in 1981 by Tim Mann for the TRS-80 computer, as a standalone version of the encoding scheme of the popular terminal emulator ''ST80-III'', for users of other terminals. It was used for sending files via major online services such as CompuServe which, not being 8-bit clean, required files to use ASCII armoring to survive. The system became very popular after Mann uploaded it to CompuServe's TRS-80 files area. The original scheme converted the binary file contents to hexadecimal numbers, encoding those as ASCII digits and letters (0–9, A–F), and adding a newline after every 60 characters. The system quickly gained the addition of a checksum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacBinary
MacBinary is a file format that combines the data fork and the resource fork of a classic Mac OS file into a single file, along with Hierarchical File System (Apple), HFS's extended metadata. The resulting file is suitable for transmission over File Transfer Protocol, FTP, the World Wide Web, and electronic mail. The documents can also be stored on computers that run operating systems with no HFS support, such as Unix or Microsoft Windows, Windows. MacBinary was widely supported on the Macintosh and was built into most communications programs on that platform. Similar solutions were built into most data compression applications on the Mac, and although these did not require MacBinary to survive transmission across non-Mac systems, MacBinary was often added in these cases to preserve longer filenames and other features. The dual-fork nature of the HFS system was not used on Mac OS X, and MacBinary has largely disappeared. Description In contrast to other computers of the era, Macin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary-to-text Encoding
A binary-to-text encoding is code, encoding of data (computing), data in plain text. More precisely, it is an encoding of binary data in a sequence of character (computing), printable characters. These encodings are necessary for transmission of data when the communication channel does not allow binary data (such as email or NNTP) or is not 8-bit clean. Pretty Good Privacy, PGP documentation () uses the term "ASCII armor" for binary-to-text encoding when referring to Base64. Overview The basic need for a binary-to-text encoding comes from a need to communicate arbitrary binary data over preexisting communications protocols that were designed to carry only English language human-readable text. Those communication protocols may only be 7-bit safe (and within that avoid certain ASCII control codes), and may require line break (computing), line breaks at certain maximum intervals, and may not maintain whitespace (computer science), whitespace. Thus, only the 94 ASCII#ASCII printable c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ASCII Armoring
A binary-to-text encoding is encoding of data in plain text. More precisely, it is an encoding of binary data in a sequence of printable characters. These encodings are necessary for transmission of data when the communication channel does not allow binary data (such as email or NNTP) or is not 8-bit clean. PGP documentation () uses the term "ASCII armor" for binary-to-text encoding when referring to Base64. Overview The basic need for a binary-to-text encoding comes from a need to communicate arbitrary binary data over preexisting communications protocols that were designed to carry only English language human-readable text. Those communication protocols may only be 7-bit safe (and within that avoid certain ASCII control codes), and may require line breaks at certain maximum intervals, and may not maintain whitespace. Thus, only the 94 printable ASCII characters are "safe" to use to convey data. Description The ASCII text-encoding standard uses 7 bits to encode characte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resource Fork
A resource fork is a fork of a file on Apple's classic Mac OS operating system that is used to store structured data. It is one of the two forks of a file, along with the data fork, which stores data that the operating system treats as unstructured. Resource fork capability has been carried over to the modern macOS for compatibility. A resource fork stores information in a specific form, containing details such as icon bitmaps, the shapes of windows, definitions of menus and their contents, and application code ( machine code). For example, a word processing file might store its text in the data fork, while storing any embedded images in the same file's resource fork. The resource fork is used mostly by executables, but any file can have a resource fork. In a 1986 technical note, Apple strongly recommended that developers do not put general data into the resource fork of a file. According to Apple, there are parts of the system software that rely on resource forks having only v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Classic Mac OS
Mac OS (originally System Software; retronym: Classic Mac OS) is the series of operating systems developed for the Mac (computer), Macintosh family of personal computers by Apple Computer, Inc. from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The Macintosh operating system is credited with having popularized the graphical user interface concept. It was included with every Macintosh that was sold during the era in which it was developed, and many updates to the system software were done in conjunction with the introduction of new Macintosh systems. Apple released the Macintosh 128K, original Macintosh on January 24, 1984. The System 1, first version of the system software, which had no official name, was partially based on the Lisa OS, which Apple previously released for the Apple Lisa, Lisa computer in 1983. As part of an agreement allowing Xerox to buy Share (finance), shares in Apple at a favorable price, it also used concepts from the PARC (company), Xerox ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
8-bit Clean
''8-bit clean'' is an attribute of computer systems, communication channels, and other devices and software, that process 8-bit character encodings without treating any byte as an in-band control code. History Until the early 1990s, many programs and data transmission channels were character-oriented and treated some characters, e.g., ETX, as control characters. Others assumed a stream of seven-bit characters, with values between 0 and 127; for example, the ASCII standard used only seven bits per character, avoiding an 8-bit representation in order to save on data transmission costs. On computers and data links using 8-bit bytes, this left the top bit of each byte free for use as a parity, flag bit, or metadata control bit. 7-bit systems and data links are unable to directly handle more complex character codes which are commonplace in non- English-speaking countries with larger alphabets. Binary files of octets cannot be transmitted through 7-bit data channels directly. To ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uuencoding
uuencoding is a form of binary-to-text encoding that originated in the Unix programs uuencode and uudecode written by Mary Ann Horton at the University of California, Berkeley in 1980, for encoding binary data for transmission in email systems. The name "uuencoding" is derived from Unix-to-Unix Copy, i.e. "Unix-to-Unix encoding" is a safe encoding for the transfer of arbitrary files from one Unix system to another Unix system but without guarantee that the intervening links would all be Unix systems. Since an email message might be forwarded through or to computers with different character sets or through transports which are not 8-bit clean, or handled by programs that are not 8-bit clean, forwarding a binary file via email might cause it to be corrupted. By encoding such data into a character subset common to most character sets, the encoded form of such data files was unlikely to be "translated" or corrupted, and would thus arrive intact and unchanged at the destination. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MS BASIC For Macintosh
MS BASIC for Macintosh was a dialect of Microsoft BASIC for Macintosh. It was one of the first Microsoft BASIC variants to have optional line numbering, predating QuickBASIC. It was provided in two versions, one with standard binary floating point and another with decimal arithmetic The decimal numeral system (also called the base-ten positional numeral system and denary or decanary) is the standard system for denoting integer and non-integer numbers. It is the extension to non-integer numbers (''decimal fractions'') of the .... References BASIC programming language Discontinued BASICs Classic Mac OS programming tools Microsoft programming languages 1983 software {{computer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macintosh File System
Macintosh File System (MFS) is a volume format (or disk file system) created by Apple Computer for storing files on 400K floppy disks. MFS was introduced with the original Apple Macintosh computer in January 1984. MFS is notable both for introducing resource forks to allow storage of structured data, and for storing metadata needed to support the graphical user interface of the classic Mac OS. MFS allows file names to be up to 255 characters in length, although Finder does not allow users to create names longer than 63 characters (31 characters in later versions). MFS is called a flat file system because it does not support a hierarchy of directories. Folders exist as a concept on the original MFS-based Macintosh, but work completely differently from the way they do on modern systems. They are visible in Finder windows, but not in the open and save dialog boxes. There is always one empty folder on the volume, and if it is altered in any way (such as by adding or renamin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembly Language
In computing, assembly language (alternatively assembler language or symbolic machine code), often referred to simply as assembly and commonly abbreviated as ASM or asm, is any low-level programming language with a very strong correspondence between the instructions in the language and the architecture's machine code instructions. Assembly language usually has one statement per machine instruction (1:1), but constants, comments, assembler directives, symbolic labels of, e.g., memory locations, registers, and macros are generally also supported. The first assembly code in which a language is used to represent machine code instructions is found in Kathleen and Andrew Donald Booth's 1947 work, ''Coding for A.R.C.''. Assembly code is converted into executable machine code by a utility program referred to as an '' assembler''. The term "assembler" is generally attributed to Wilkes, Wheeler and Gill in their 1951 book '' The Preparation of Programs for an Electronic Dig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexadecimal
Hexadecimal (also known as base-16 or simply hex) is a Numeral system#Positional systems in detail, positional numeral system that represents numbers using a radix (base) of sixteen. Unlike the decimal system representing numbers using ten symbols, hexadecimal uses sixteen distinct symbols, most often the symbols "0"–"9" to represent values 0 to 9 and "A"–"F" to represent values from ten to fifteen. Software developers and system designers widely use hexadecimal numbers because they provide a convenient representation of binary code, binary-coded values. Each hexadecimal digit represents four bits (binary digits), also known as a nibble (or nybble). For example, an 8-bit byte is two hexadecimal digits and its value can be written as to in hexadecimal. In mathematics, a subscript is typically used to specify the base. For example, the decimal value would be expressed in hexadecimal as . In programming, several notations denote hexadecimal numbers, usually involving a prefi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Byte
The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable unit of memory in many computer architectures. To disambiguate arbitrarily sized bytes from the common 8-bit definition, network protocol documents such as the Internet Protocol () refer to an 8-bit byte as an octet. Those bits in an octet are usually counted with numbering from 0 to 7 or 7 to 0 depending on the bit endianness. The size of the byte has historically been hardware-dependent and no definitive standards existed that mandated the size. Sizes from 1 to 48 bits have been used. The six-bit character code was an often-used implementation in early encoding systems, and computers using six-bit and nine-bit bytes were common in the 1960s. These systems often had memory words of 12, 18, 24, 30, 36, 48, or 60 bits, corresponding t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
