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Atari FREDDIE
FREDDIE is the name for a 40-pin large scale integrated circuit found in later model Atari 8-bit computers. It is a RAM address multiplexer, used for DRAM access. Atari created this chip to replace several other chips to cut costs and to enhance CPU and ANTIC memory access. FREDDIE, combined with a C061618 MMU (XL/XE) and C025953 EMMU (130XE) allows the CPU and ANTIC to access memory independently of each other. Originally designed for the cancelled 1400XL and 1450XLD, it was eventually used in the 800XLF (labelled "800XL," refers to European version), 65XE, 130XE, and XEGS. External linksatarimuseum.comFreddie MCU Engineering Data (PDF file)Freddie info and diagram {{compu-storage-stub FREDDIE, Atari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
The Atari FREDDIE
''The'' is a grammatical article in English, denoting nouns that are already or about to be mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the most frequently used word in the English language; studies and analyses of texts have found it to account for seven percent of all printed English-language words. It is derived from gendered articles in Old English which combined in Middle English and now has a single form used with nouns of any gender. The word can be used with both singular and plural nouns, and with a noun that starts with any letter. This is different from many other languages, which have different forms of the definite article for different genders or numbers. Pronunciation In most dialects, "the" is pronounced as (with the voiced dental fricative followed by a schwa) when followed by a consonant sound, and as (homophone of the archaic pronoun ''thee'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Atari FREDDIE
FREDDIE is the name for a 40-pin large scale integrated circuit found in later model Atari 8-bit computers. It is a RAM address multiplexer, used for DRAM access. Atari created this chip to replace several other chips to cut costs and to enhance CPU and ANTIC memory access. FREDDIE, combined with a C061618 MMU (XL/XE) and C025953 EMMU (130XE) allows the CPU and ANTIC to access memory independently of each other. Originally designed for the cancelled 1400XL and 1450XLD, it was eventually used in the 800XLF (labelled "800XL," refers to European version), 65XE, 130XE, and XEGS. External linksatarimuseum.comFreddie MCU Engineering Data (PDF file)Freddie info and diagram {{compu-storage-stub FREDDIE, Atari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Atari 8-bit Computers
The Atari 8-bit computers, formally launched as the Atari Home Computer System, are a series of home computers introduced by Atari, Inc., in 1979 with the Atari 400 and Atari 800. The architecture is designed around the 8-bit MOS Technology 6502 CPU and three custom coprocessors which provide support for sprites, smooth multidirectional scrolling, four channels of audio, and other features. The graphics and sound are more advanced than most of its contemporaries, and video games are a key part of the software library. The 1980 first-person space combat simulator ''Star Raiders'' is considered the platform's killer app. The Atari 800 was positioned as a high-end model and the 400 as more affordable. The 400 has a pressure-sensitive, spillproof membrane keyboard and initially shipped with a non-upgradable of RAM. The 800 has a conventional keyboard, a second cartridge slot, and allows easy RAM upgrades to 48K. Both use identical 6502 CPUs at ( for PAL versions) and coprocess ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Random-access Memory
Random-access memory (RAM; ) is a form of Computer memory, electronic computer memory that can be read and changed in any order, typically used to store working Data (computing), data and machine code. A random-access memory device allows data items to be read (computer), read or written in almost the same amount of time irrespective of the physical location of data inside the memory, in contrast with other direct-access data storage media (such as hard disks and Magnetic tape data storage, magnetic tape), where the time required to read and write data items varies significantly depending on their physical locations on the recording medium, due to mechanical limitations such as media rotation speeds and arm movement. In today's technology, random-access memory takes the form of integrated circuit (IC) chips with MOSFET, MOS (metal–oxide–semiconductor) Memory cell (computing), memory cells. RAM is normally associated with Volatile memory, volatile types of memory where s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Multiplexer
In electronics, a multiplexer (or mux; spelled sometimes as multiplexor), also known as a data selector, is a device that selects between several Analog signal, analog or Digital signal (electronics), digital input signals and forwards the selected input to a single output line. The selection is directed by a separate set of digital inputs known as select lines. A multiplexer of 2^n inputs has n select lines, which are used to select which input line to send to the output. A multiplexer makes it possible for several input signals to share one device or resource, for example, one analog-to-digital converter or one communications transmission medium, instead of having one device per input signal. Multiplexers can also be used to implement Boolean algebra, Boolean functions of multiple variables. Conversely, a demultiplexer (or demux) is a device that takes a single input signal and selectively forwards it to one of several output lines. A multiplexer is often used with a complem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Dynamic Random-access Memory
Dynamics (from Greek language, Greek δυναμικός ''dynamikos'' "powerful", from δύναμις ''dynamis'' "power (other), power") or dynamic may refer to: Physics and engineering * Dynamics (mechanics), the study of forces and their effect on motion Brands and enterprises * Dynamic (record label), an Italian record label in Genoa Mathematics * Dynamical system, a concept describing a point's time dependency ** Topological dynamics, the study of dynamical systems from the viewpoint of general topology * Symbolic dynamics, a method to model dynamical systems Social science * Group dynamics, the study of social group processes especially * Population dynamics, in life sciences, the changes in the composition of a population * Psychodynamics, the study of psychological forces driving human behavior * Social dynamics, the ability of a society to react to changes * Spiral Dynamics, a social development theory Other uses * Dynamics (music), the softness or loudn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
ANTIC
Alphanumeric Television Interface Controller (ANTIC) is an LSI ASIC dedicated to generating 2D computer graphics to be shown on a television screen or computer display. Under the direction of Jay Miner, the chip was designed in 1977–1978 by Joe Decuir, Francois Michel, and Steve Smith for the Atari 8-bit computers first released in 1979. The chip was patented by Atari, Inc. in 1981. ANTIC is also used in the 1982 Atari 5200 video game console, which shares most of the same hardware as the 8-bit computers. For every frame of video, ANTIC reads instructions to define the playfield, or background graphics, then delivers a data stream to the companion CTIA or GTIA chip which adds color and overlays sprites (referred to as "Player/Missile graphics" by Atari). Each ANTIC instruction corresponds to either blank scan lines or one of 14 graphics modes used for a horizontal band of the display. The height of each band depends on the mode. The instructions comprise a display l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Atari MMU
Atari MMU is a custom memory management unit chip for the Atari 8-bit computers. It enables access to the hardware registers on ANTIC, GTIA, POKEY and 6520 PIA. The later XL/XE MMU (C061618) also selects OS ROM, Atari BASIC ROM, self-test ROM and LEDs in the 1200XL. On the 128K 130XE the EMMU chip handles similar functionality. The user cannot directly manipulate the Atari MMU, but selects the various ROMS and memory via the memory-mapped hardware register known as PORTB (5401710 or D30116). Atari changed PORTB from an input port on the 400/800 machines to an output port on the XL/XE machines, leaving two joystick ports instead of four on the XL/XE machines. By setting and clearing specific bits in PORTB, the user can access either the ROMs or memory locations. No synchronization is required as the OS handles the access. The bit assignments for PORTB on the XL/XE machines are: The 1200XL does not have BASIC built-in. See also * Atari FREDDIE FREDDIE is the name for a 40 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
