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Machine Code Monitor
A machine code monitor ( machine language monitor) is software that allows a user to enter commands to view and change memory locations on a computer, with options to load and save memory contents from/to secondary storage. Some full-featured machine code monitors provide detailed control ("single-stepping") of the execution of machine language programs (much like a debugger), and include absolute-address code assembly and disassembly capabilities. Motorola published the MIKBUG ROM monitor for the 6800 in 1973 and the BUFFALO ROM monitor for the 68HC11. Machine code monitors became popular during the home computer era of the 1970s and 1980s and were sometimes available as resident firmware in some computers (e.g., the built-in monitors in the Commodore 128, Heathkit H89 and Zenith laptops). Often, computer manufacturers rely on their ROM-resident monitors to permit users to reconfigure their computers following installation of upgrade hardware, such as expanded main memo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
W65C816S Machine Code Monitor
The W65C816S (also 65C816 or 65816) is an 8/16-bit microprocessor (MPU) developed and sold by the Western Design Center (WDC). Introduced in 1985, the W65C816S is an enhanced version of the WDC 65C02 8-bit MPU, itself a CMOS enhancement of the venerable MOS Technology 6502 NMOS MPU. The 65C816 was the CPU for the Apple IIGS and, in modified form, the Super Nintendo Entertainment System. The ''65'' in the part's designation comes from its 65C02 compatibility mode, and the ''816'' signifies that the MPU has selectable 8- and 16-bit register sizes. In addition to the availability of 16-bit registers, the W65C816S features extended memory addressing to 24 bits, supporting up to 16 megabytes of random-access memory, an enhanced instruction set, and a 16 bit stack pointer, as well as several new electrical signals for improved system hardware management. At reset, the W65C816S starts in "emulation mode", meaning it substantially behaves as a 65C02. Thereafter, the W65C816S may be sw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commodore 128
The Commodore 128, also known as the C128, C-128, C= 128,The "C=" represents the graphical part of the logo. is the last 8-bit home computer that was commercially released by Commodore Business Machines (CBM). Introduced in January 1985 at the CES in Las Vegas, it appeared three years after its predecessor, the bestselling computer in the 80s Commodore 64. The C128 is a significantly expanded successor to the C64, with nearly full compatibility. The newer machine has 128 KB of RAM in two 64 KB banks, and an 80-column color video output. It has a redesigned case and keyboard. Also included is a Zilog Z80 CPU which allows the C128 to run CP/M, as an alternative to the usual Commodore BASIC environment. The presence of the Z80 and the huge CP/M software library it brings, coupled with the C64's software library, gave the C128 one of the broadest ranges of available software among its competitors. The primary hardware designer of the C128 was Bil Herd, who had worked on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hacker (hobbyist)
The hacker culture is a subculture of individuals who enjoy—often in collective effort—the intellectual challenge of creatively overcoming the limitations of software systems or electronic hardware (mostly digital electronics), to achieve novel and clever outcomes. The act of engaging in activities (such as programming or other mediaThe Hacker Community and Ethics: An Interview with Richard M. Stallman, 2002 (gnu.org)) in a spirit of playfulness and exploration is termed ''hacking''. However, the defining characteristic of a hacker is not the activities performed themselves (e.g. programmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Program
A computer program is a sequence or set of instructions in a programming language for a computer to execute. Computer programs are one component of software, which also includes documentation and other intangible components. A computer program in its human-readable form is called source code. Source code needs another computer program to execute because computers can only execute their native machine instructions. Therefore, source code may be translated to machine instructions using the language's compiler. (Assembly language programs are translated using an assembler.) The resulting file is called an executable. Alternatively, source code may execute within the language's interpreter. If the executable is requested for execution, then the operating system loads it into memory and starts a process. The central processing unit will soon switch to this process so it can fetch, decode, and then execute each machine instruction. If the source code is requested for executio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assembly Language
In computer programming, assembly language (or 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 Di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Patch (computing)
A patch is a set of changes to a computer program or its supporting data designed to update, fix, or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually being called bugfixes or bug fixes. Patches are often written to improve the functionality, usability, or performance of a program. The majority of patches are provided by software vendors for operating system and application updates. Patches may be installed either under programmed control or by a human programmer using an editing tool or a debugger. They may be applied to program files on a storage device, or in computer memory. Patches may be permanent (until patched again) or temporary. Patching makes possible the modification of compiled and machine language object programs when the source code is unavailable. This demands a thorough understanding of the inner workings of the object code by the person creating the patch, which is difficult without close study of the sourc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Processor Register
A processor register is a quickly accessible location available to a computer's processor. Registers usually consist of a small amount of fast storage, although some registers have specific hardware functions, and may be read-only or write-only. In computer architecture, registers are typically addressed by mechanisms other than main memory, but may in some cases be assigned a memory address e.g. DEC PDP-10, ICT 1900. Almost all computers, whether load/store architecture or not, load data from a larger memory into registers where it is used for arithmetic operations and is manipulated or tested by machine instructions. Manipulated data is then often stored back to main memory, either by the same instruction or by a subsequent one. Modern processors use either static or dynamic RAM as main memory, with the latter usually accessed via one or more cache levels. Processor registers are normally at the top of the memory hierarchy, and provide the fastest way to access data. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interrupt
In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted, the processor will suspend its current activities, save its state, and execute a function called an '' interrupt handler'' (or an ''interrupt service routine'', ISR) to deal with the event. This interruption is often temporary, allowing the software to resume normal activities after the interrupt handler finishes, although the interrupt could instead indicate a fatal error. Interrupts are commonly used by hardware devices to indicate electronic or physical state changes that require time-sensitive attention. Interrupts are also commonly used to implement computer multitasking, especially in real-time computing. Systems that use interrupts in these ways are said to be interrupt-driven. Types Interrupt signals may be issued in response t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microprocessor
A microprocessor is a computer processor where the data processing logic and control is included on a single integrated circuit, or a small number of integrated circuits. The microprocessor contains the arithmetic, logic, and control circuitry required to perform the functions of a computer's central processing unit. The integrated circuit is capable of interpreting and executing program instructions and performing arithmetic operations. The microprocessor is a multipurpose, clock-driven, register-based, digital integrated circuit that accepts binary data as input, processes it according to instructions stored in its memory, and provides results (also in binary form) as output. Microprocessors contain both combinational logic and sequential digital logic, and operate on numbers and symbols represented in the binary number system. The integration of a whole CPU onto a single or a few integrated circuits using Very-Large-Scale Integration (VLSI) greatly reduced the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
6502
The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small team led by Chuck Peddle for MOS Technology. The design team had formerly worked at Motorola on the Motorola 6800 project; the 6502 is essentially a simplified, less expensive and faster version of that design. When it was introduced in 1975, the 6502 was the least expensive microprocessor on the market by a considerable margin. It initially sold for less than one-sixth the cost of competing designs from larger companies, such as the 6800 or Intel 8080. Its introduction caused rapid decreases in pricing across the entire processor market. Along with the Zilog Z80, it sparked a series of projects that resulted in the home computer revolution of the early 1980s. Popular video game consoles and home computers of the 1980s and early 1990s, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debugging
In computer programming and software development, debugging is the process of finding and resolving '' bugs'' (defects or problems that prevent correct operation) within computer programs, software, or systems. Debugging tactics can involve interactive debugging, control flow analysis, unit testing, integration testing, log file analysis, monitoring at the application or system level, memory dumps, and profiling. Many programming languages and software development tools also offer programs to aid in debugging, known as '' debuggers''. Etymology The terms "bug" and "debugging" are popularly attributed to Admiral Grace Hopper in the 1940s. While she was working on a Mark II computer at Harvard University, her associates discovered a moth stuck in a relay and thereby impeding operation, whereupon she remarked that they were "debugging" the system. However, the term "bug", in the sense of "technical error", dates back at least to 1878 and Thomas Edison who describes the " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heathkit H89
The Z-89 is a personal computer produced by Zenith Data Systems (ZDS) in the early 1980s. Description The Zenith Z-89 is based on the Zilog Z80 microprocessor running at 2.048 MHz, and supports the HDOS and CP/M operating systems. The US$2295 Z-89 is integrated in a terminal-like enclosure with a non-detachable keyboard, 12-inch monochrome CRT with a 80x25 screen, 48 KB RAM, and a 5.25" floppy disk drive. The keyboard is of high build quality and has an unusual number of special purpose keys: REPEAT, ESC, TAB, CAPS, CTRL, SCROLL, RESET, BREAK, BACK SPACE, LINE FEED, DELETE, REPEAT, and two with red and blue squares. There are five function keys and a numeric keypad. The video display has reverse video and block graphics are available. The computer has two small card cages inside the cabinet on either side of the CRT, each of which accept up to three proprietary circuit cards. Upgrade cards available for this included disk controller cards (see below), a 16 KB RA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
