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IQ 151
The IQ 151 was a personal computer produced by ''ZPA Nový Bor'' in the former Czechoslovakia. It had a Tesla (Czechoslovak company), Tesla MHB8080A (copy of Intel 8080) Central processing unit, CPU running at 2 MHz, 32 kilobyte, KB Random access memory, RAM (later on 64 KB), 4 KB Read-only memory, ROM, with Semigraphics, semigraphic text mode video output and the BASIC programming language. The mainboard contained only CPU, supporting ICs and memory. Everything else was added by expansion modules, with five available slots. Like mentioned above, elementary expansion modules are ''Basic 6,'' a BASIC language interpreter and ''Video 32'',a video generator, producing 32 columns and 32 rows of text and Semigraphics, semigraphic characters. Advanced expansion modules include V''ideo 64,'' allowing 64 x 32 character text display; ''Grafik,'' adding true 512 x 256 monochromatic graphics and ''Basic G,'' with additional graphical functions to BASIC; ''Pascal'', and edit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Personal Computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or technician. Unlike large, costly minicomputers and mainframes, time-sharing by many people at the same time is not used with personal computers. Primarily in the late 1970s and 1980s, the term home computer was also used. Institutional or corporate computer owners in the 1960s had to write their own programs to do any useful work with the machines. While personal computer users may develop their own applications, usually these systems run commercial software, free-of-charge software ("freeware"), which is most often proprietary, or free and open-source software, which is provided in "ready-to-run", or binary, form. Software for personal computers is typically developed and distributed independently from the hardware or operating system ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital-to-analog Converter
In electronics, a digital-to-analog converter (DAC, D/A, D2A, or D-to-A) is a system that converts a digital signal into an analog signal. An analog-to-digital converter (ADC) performs the reverse function. There are several DAC architectures; the suitability of a DAC for a particular application is determined by figures of merit including: resolution, maximum sampling frequency and others. Digital-to-analog conversion can degrade a signal, so a DAC should be specified that has insignificant errors in terms of the application. DACs are commonly used in music players to convert digital data streams into analog audio signals. They are also used in televisions and mobile phones to convert digital video data into analog video signals. These two applications use DACs at opposite ends of the frequency/resolution trade-off. The audio DAC is a low-frequency, high-resolution type while the video DAC is a high-frequency low- to medium-resolution type. Due to the complexity a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Keyboard
A membrane keyboard is a computer keyboard whose "keys" are not separate, moving parts, as with the majority of other keyboards, but rather are pressure pads that have only outlines and symbols printed on a flat, flexible surface. Very little, if any, tactile feedback is felt when using such a keyboard. Membrane keyboards work by electrical contact between the keyboard surface and the underlying circuits when keytop areas are pressed. These models were used with some early 1980s home computers, enjoying wide adoption in consumer electronics devices. The keyboards are quite inexpensive to mass-produce, and are more resistant against dirt and liquids than most other keyboards. However, due to a low or non-existent tactile feedback, most people have difficulty typing with them, especially when larger numbers of characters are being typed. Chiclet keyboards were a slight improvement, at least allowing individual keys to be felt to some extent. Aside from early hobbyist/kit/home comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western World
The Western world, also known as the West, primarily refers to the various nations and state (polity), states in the regions of Europe, North America, and Oceania.Western Civilization Our Tradition; James Kurth; accessed 30 August 2011 The Western world is also known as the Occident (from the Latin word ''occidēns'' "setting down, sunset, west") in contrast to the Eastern world known as the Orient (from the Latin word ''oriēns'' "origin, sunrise, east"). Following the Discovery of America in 1492, the West came to be known as the "world of business" and trade; and might also mean the Northern half of the North–South divide, the countries of the ''Global North'' (often equated with capitalist Developed country, developed countries). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Currency
A currency, "in circulation", from la, currens, -entis, literally meaning "running" or "traversing" is a standardization of money in any form, in use or circulation as a medium of exchange, for example banknotes and coins. A more general definition is that a currency is a ''system of money'' in common use within a specific environment over time, especially for people in a nation state. Under this definition, the British Pound Sterling (£), euros (€), Japanese yen (¥), and U.S. dollars (US$)) are examples of (government-issued) fiat currencies. Currencies may act as stores of value and be traded between nations in foreign exchange markets, which determine the relative values of the different currencies. Currencies in this sense are either chosen by users or decreed by governments, and each type has limited boundaries of acceptance - i.e. legal tender laws may require a particular unit of account for payments to government agencies. Other definitions of the term "curren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PMD 85
The PMD 85 is an 8-bit personal computer produced since 1985 by the companies Tesla Piešťany and Tesla Bratislava in the former Czechoslovakia. They were deployed ''en masse'' in schools throughout Slovakia (while the IQ 151 performed a similar role in the Czech part of the country). The first Czechoslovak video games were created on the PMD 85 (other platforms were ZX Spectrum and Atari). The production was local due to a lack of foreign currencies for purchasing systems from the West.{{Citation needed, date=May 2007 After the Velvet Revolution in 1989, the production was stopped. The PMD 85 was not competitive in quality or features compared to foreign PCs available at that time. Specifications * MHB8080A 2.048 MHz CPU (clone of Intel 8080) * 48 KiB RAM (PMD 85-2A and 3, 64 KiB) * 4 KiB ROM (PMD 85-3, 8 KiB) * System monitor * Tape utilities * TV output ( B/W, PMD 85-3 PAL) or RGB component video * 288×256 resolution * 4-level attribute (flickering, graysca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slovakia
Slovakia (; sk, Slovensko ), officially the Slovak Republic ( sk, Slovenská republika, links=no ), is a landlocked country in Central Europe. It is bordered by Poland to the north, Ukraine to the east, Hungary to the south, Austria to the southwest, and the Czech Republic to the northwest. Slovakia's mostly mountainous territory spans about , with a population of over 5.4 million. The capital and largest city is Bratislava, while the second largest city is Košice. The Slavs arrived in the territory of present-day Slovakia in the fifth and sixth centuries. In the seventh century, they played a significant role in the creation of Samo's Empire. In the ninth century, they established the Principality of Nitra, which was later conquered by the Principality of Moravia to establish Great Moravia. In the 10th century, after the dissolution of Great Moravia, the territory was integrated into the Principality of Hungary, which then became the Kingdom of Hungary in 1000. In 1241 a ... [...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) 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 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. Operation Development of the EPROM memory cell started with investigation of faulty integrated circuits where the gate connections of transistors had broken ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CP/M
CP/M, originally standing for Control Program/Monitor and later Control Program for Microcomputers, is a mass-market operating system created in 1974 for Intel 8080/ 85-based microcomputers by Gary Kildall of Digital Research, Inc. Initially confined to single-tasking on 8-bit processors and no more than 64 kilobytes of memory, later versions of CP/M added multi-user variations and were migrated to 16-bit processors. The combination of CP/M and S-100 bus computers became an early standard in the microcomputer industry. This computer platform was widely used in business through the late 1970s and into the mid-1980s. CP/M increased the market size for both hardware and software by greatly reducing the amount of programming required to install an application on a new manufacturer's computer. An important driver of software innovation was the advent of (comparatively) low-cost microcomputers running CP/M, as independent programmers and hackers bought them and shared their crea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floppy Disk
A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined with a fabric that removes dust particles from the spinning disk. Floppy disks store digital data which can be read and written when the disk is inserted into a floppy disk drive (FDD) connected to or inside a computer or other device. The first floppy disks, invented and made by IBM, had a disk diameter of . Subsequently, the 5¼-inch and then the 3½-inch became a ubiquitous form of data storage and transfer into the first years of the 21st century. 3½-inch floppy disks can still be used with an external USB floppy disk drive. USB drives for 5¼-inch, 8-inch, and other-size floppy disks are rare to non-existent. Some individuals and organizations continue to use older equipment to read or transfer data from floppy disks. Floppy disk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Floppy-disk Controller
A floppy-disk controller (FDC) has evolved from a discrete set of components on one or more circuit boards to a special-purpose integrated circuit (IC or "chip") or a component thereof. An FDC directs and controls reading from and writing to a computer's floppy disk drive (FDD). The FDC is responsible for reading data presented from the host computer and converting it to the drive's on-disk format using one of a number of encoding schemes, like FM encoding (single density) or MFM encoding (double density), and reading those formats and returning it to its original binary values. Depending on the platform, data transfers between the controller and host computer would be controlled by the computer's own microprocessor, or an inexpensive dedicated microprocessor like the MOS 6507 or Zilog Z80. Early controllers required additional circuitry to perform specific tasks like providing clock signals and setting various options. Later designs included more of this functionality on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serial Port
In computing, a serial port is a serial communication interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in parallel. Throughout most of the history of personal computers, data has been transferred through serial ports to devices such as modems, terminals, various peripherals, and directly between computers. While interfaces such as Ethernet, FireWire, and USB also send data as a serial stream, the term ''serial port'' usually denotes hardware compliant with RS-232 or a related standard, such as RS-485 or RS-422. Modern consumer personal computers (PCs) have largely replaced serial ports with higher-speed standards, primarily USB. However, serial ports are still frequently used in applications demanding simple, low-speed interfaces, such as industrial automation systems, scientific instruments, point of sale systems and some industrial and consumer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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