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PC532
The PC532 was a "home-brew" microcomputer design created by George Scolaro and Dave Rand in 1989-1990, based on the National Semiconductor NS32532 microprocessor (a member of the NS320xx series). Full hardware documentation for the design, including schematics and PAL programming data, was made freely available, and a short run (around 200) of motherboard PCBs were produced for hobbyists to populate and assemble into fully functional systems. Hardware specifications * PC/AT form-factor motherboard * NS32532 CPU and NS32381 FPU (25 MHz) * 4 to 32 MB of RAM * National Semiconductor DP8490 SCSI host adapter * Adaptec AIC-6250 SCSI host adapter * Four SCN2861 DUARTs (providing 8 serial ports) * 27256 32 kB firmware EPROM Operating systems The following operating systems were ported to the PC532: ;MINIX: A port of MINIX 1.3 to the PC532 (sometimes referred to as MINIX-532) was released by Bruce Culbertson in 1990. ;Mach: Mach 3.0 was ported to the PC532 in 1992 by Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NS320xx
The NS32000, sometimes known as the 32k, is a series of microprocessors produced by National Semiconductor. Design work began around 1980 and it was announced at the International Solid-State Circuits Conference in April 1981. The first member of the family came to market in 1982, briefly known as the 16032 before being renamed as the 32016. It was the first general-purpose microprocessor on the market that used 32-bit data internally: the Motorola 68000 had 32-bit registers and instructions to perform 32-bit arithmetic, but used a 16-bit ALU for arithmetic operations on data, and thus took twice as long as the 32016 to perform those arithmetic operations. However, the 32016 contained many bugs and often could not be run at its rated speed. These problems, and the presence of the otherwise similar 68000 which had been available since 1980, led to little use in the market despite considerable early interest. Several improved versions followed, including 1985's 32032 which was ess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NetBSD
NetBSD is a free and open-source Unix-like operating system based on the Berkeley Software Distribution (BSD). It was the first open-source BSD descendant officially released after 386BSD was fork (software development), forked. It continues to be actively developed and is available for many platforms, including servers, desktops, handheld devices, and embedded systems. The NetBSD project focuses on code clarity, careful design, and portability across many computer architectures. Its source code is publicly available and Permissive free software licence, permissively licensed. History NetBSD was originally derived from the 4.3BSD-Reno release of the Berkeley Software Distribution from the Computer Systems Research Group of the University of California, Berkeley, via its Net/2 source code release and the 386BSD project. The NetBSD project began as a result of frustration within the 386BSD developer community with the pace and direction of the operating system's development. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcomputer
A microcomputer is a small, relatively inexpensive computer having a central processing unit (CPU) made out of a microprocessor. The computer also includes memory and input/output (I/O) circuitry together mounted on a printed circuit board (PCB). Microcomputers became popular in the 1970s and 1980s with the advent of increasingly powerful microprocessors. The predecessors to these computers, mainframes and minicomputers, were comparatively much larger and more expensive (though indeed present-day mainframes such as the IBM System z machines use one or more custom microprocessors as their CPUs). Many microcomputers (when equipped with a keyboard and screen for input and output) are also personal computers (in the generic sense). An early use of the term "personal computer" in 1962 predates microprocessor-based designs. ''(See "Personal Computer: Computers at Companies" reference below)''. A "microcomputer" used as an embedded control system may have no human-readable input and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MINIX
MINIX is a Unix-like operating system based on a microkernel Software architecture, architecture, first released in 1987 and written by American-Dutch computer scientist Andrew S. Tanenbaum. It was designed as a clone of the Unix operating system and one that could run on affordable, Intel 8086-based home computers; MINIX was targeted for use in classrooms by computer science students at universities. Its name comes from ''mini-Unix''. MINIX was initially Source-available software, proprietary source-available, but was relicensed under the BSD licenses, BSD 3-Clause to become free and open-source software, free and open-source in 2000. MINIX was ported to various additional platforms in the 1990s, and version 2.0 was released in 1997 and was the first to be POSIX compliant. Starting with MINIX 3, released in 2005, the primary aim of development shifted from education to the creation of a high availability, highly reliable and Self-management (computer science), self-healing micro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field-programmable Gate Array
A field-programmable gate array (FPGA) is a type of configurable integrated circuit that can be repeatedly programmed after manufacturing. FPGAs are a subset of logic devices referred to as programmable logic devices (PLDs). They consist of an array of programmable logic device, programmable logic block, logic blocks with a connecting grid, that can be configured "in the field" to interconnect with other logic blocks to perform various digital functions. FPGAs are often used in limited (low) quantity production of custom-made products, and in research and development, where the higher cost of individual FPGAs is not as important, and where creating and manufacturing a custom circuit would not be feasible. Other applications for FPGAs include the telecommunications, automotive, aerospace, and industrial sectors, which benefit from their flexibility, high signal processing speed, and parallel processing abilities. A FPGA configuration is generally written using a hardware descr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU Compiler Collection
The GNU Compiler Collection (GCC) is a collection of compilers from the GNU Project that support various programming languages, Computer architecture, hardware architectures, and operating systems. The Free Software Foundation (FSF) distributes GCC as free software under the GNU General Public License (GNU GPL). GCC is a key component of the GNU toolchain which is used for most projects related to GNU and the Linux kernel. With roughly 15 million lines of code in 2019, GCC is one of the largest free programs in existence. It has played an important role in the growth of free software, as both a tool and an example. When it was first released in 1987 by Richard Stallman, GCC 1.0 was named the GNU C Compiler since it only handled the C (programming language), C programming language. It was extended to compile C++ in December of that year. Compiler#Front end, Front ends were later developed for Objective-C, Objective-C++, Fortran, Ada (programming language), Ada, Go (programming la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
386BSD
386BSD (also known as "Jolix") is a Unix-like operating system that was developed by couple Lynne and William "Bill" Jolitz. Released as free and open source in 1992, it was the first fully operational Unix built to run on IBM PC-compatible systems based on the Intel 80386 ("i386") microprocessor, and the first Unix-like system on affordable home-class hardware to be freely distributed. Its innovations included role-based security, ring buffers, self-ordered configuration and modular kernel design. Development began in 1989 while the Jolitzes were at the University of California, Berkeley's Computer Systems Research Group (CSRG), intended to be a port of BSD to 386-based personal computers. They then contributed the project to the university with some of the work ending up in BSD's Net/2, distributed in 1991. However when the CSRG scrapped the project and ruled that his work was "university proprietary", Jolitz rewrote the code from scratch, based on the incomplete free c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unix
Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and others. Initially intended for use inside the Bell System, AT&T licensed Unix to outside parties in the late 1970s, leading to a variety of both academic and commercial Unix variants from vendors including University of California, Berkeley ( BSD), Microsoft (Xenix), Sun Microsystems ( SunOS/ Solaris), HP/ HPE ( HP-UX), and IBM ( AIX). The early versions of Unix—which are retrospectively referred to as " Research Unix"—ran on computers such as the PDP-11 and VAX; Unix was commonly used on minicomputers and mainframes from the 1970s onwards. It distinguished itself from its predecessors as the first portable operating system: almost the entire operating system is written in the C programming language (in 1973), which allows U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berkeley Software Distribution
The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginning in 1978. It began as an improved derivative of AT&T's original Unix that was developed at Bell Labs, based on the source code but over time diverging into its own code. BSD would become a pioneer in the advancement of Unix and computing. BSD's development was begun initially by Bill Joy, who added virtual memory capability to Unix running on a VAX-11 computer. In the 1980s, BSD was widely adopted by workstation vendors in the form of proprietary Unix distributions such as DEC Ultrix and Sun Microsystems SunOS due to its permissive licensing and familiarity to many technology company founders and engineers. It also became the most popular Unix at universities, where it was used for the study of operating systems. BSD was sponsored ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SSH Communications Security
The Secure Shell Protocol (SSH Protocol) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH was designed for Unix-like operating systems as a replacement for Telnet and unsecured remote Unix shell protocols, such as the Berkeley Remote Shell (rsh) and the related rlogin and rexec protocols, which all use insecure, plaintext methods of authentication, like passwords. Since mechanisms like Telnet and Remote Shell are designed to access and operate remote computers, sending the authentication tokens (e.g. username and password) for this access to these computers across a public network in an unsecured way poses a great risk of 3rd parties obtaining the password and achieving the same level of access to the remote system as the telnet user. Secure Shell mitigates this risk through the use of encryption mechanisms that are intended to hide the content ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mach (kernel)
Mach () is an operating system kernel developed at Carnegie Mellon University by Richard Rashid and Avie Tevanian to support operating system research, primarily distributed and parallel computing. Mach is often considered one of the earliest examples of a microkernel. However, not all versions of Mach are microkernels. Mach's derivatives are the basis of the operating system kernel in GNU Hurd and of Apple's XNU kernel used in macOS, iOS, iPadOS, tvOS, and watchOS. The project at Carnegie Mellon ran from 1985 to 1994, ending with Mach 3.0, which is a true microkernel. Mach was developed as a replacement for the kernel in the BSD version of Unix, not requiring a new operating system to be designed around it. Mach and its derivatives exist within several commercial operating systems. These include all using the XNU operating system kernel which incorporates an earlier non-microkernel Mach as a major component. The Mach virtual memory management system was also adopted in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EPROM
An EPROM (rarely EROM), or erasable programmable read-only memory, is a type of programmable read-only memory (PROM) integrated circuit, chip that retains its data when its power supply is switched off. Computer memory that can retrieve stored data after a power supply has been turned off and back on is called non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages than those normally used in digital circuits. Once programmed, an EPROM can be erased by exposing it to strong ultraviolet (UV) light source (such as from a mercury-vapor lamp). EPROMs are easily recognizable by the transparent fused quartz (or on later models' resin) window on the top of the package, through which the silicon chip is visible, and which permits exposure to ultraviolet light during erasing. It was invented by Dov Frohman in 1971. Operation Development of the EPROM memory cell (computing), memory cell started with investi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
