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65-588: Several peripherals were available for the system in North America, including an expander with three cartridge jacks (some of the cartridge-based games used two cartridges), a cassette-tape recorder , a 5.25" floppy disk drive , a printer, and a touchpad . The PC-6000 series was followed by the PC-6600 series . New Nippon Electric ( 新日本電気 , Shin Nippon Denki ) was a subsidiary of NEC and

130-469: A bus (historically also called data highway or databus ) is a communication system that transfers data between components inside a computer , or between computers. This expression covers all related hardware components (wire, optical fiber , etc.) and software , including communication protocols . In most traditional computer architectures , the CPU and main memory tend to be tightly coupled, with

195-417: A cartridge , cart , cassette , or card , is a replaceable part designed to be connected to a consumer electronics device such as a home computer , video game console or, to a lesser extent, electronic musical instruments . ROM cartridges allow users to rapidly load and access programs and data alongside a floppy drive in a home computer; in a video game console, the cartridges are standalone. At

260-560: A chiclet keyboard while a North American version ( PC-6001A ) uses a typewriter keyboard. The PC-6001 MK2 has 64 KB memory, 16 KB video RAM, a 5 + 1 ⁄ 4 -inch 2D floppy drive interface, Kanji character generator, RGB monitor out, speech synthesizer unit and a typewriter keyboard. It supports following screen modes: 40x20 characters, 80x80 pixel graphics with 15 colors, 160x200 graphics with 15 colors, and 320x200 graphics with 4 colors. Cartridge-based game A ROM cartridge , usually referred to in context simply as

325-457: A game cartridge . ROM cartridges were popularized by early home computers which featured a special bus port for the insertion of cartridges containing software in ROM . In most cases the designs were fairly crude, with the entire address and data buses exposed by the port and attached via an edge connector ; the cartridge was memory mapped directly into the system's address space such that

390-418: A processor or DMA -enabled device needs to read or write to a memory location, it specifies that memory location on the address bus (the value to be read or written is sent on the data bus). The width of the address bus determines the amount of memory a system can address. For example, a system with a 32-bit address bus can address 2 (4,294,967,296) memory locations. If each memory location holds one byte,

455-479: A "games" module. Modules were not user-programmable. The Hewlett-Packard HP-41C had expansion slots which could hold ROM memory as well as I/O expansion ports. Computers using cartridges in addition to magnetic media are the VIC-20 and Commodore 64 , MSX , Atari 8-bit computers , TI-99/4A (where they were called Solid State Command Modules and were not directly mapped to the system bus) and IBM PCjr (where

520-730: A bidirectional data bus, re-using the same wires for input and output at different times. Some processors use a dedicated wire for each bit of the address bus, data bus, and the control bus. For example, the 64-pin STEbus is composed of 8 physical wires dedicated to the 8-bit data bus, 20 physical wires dedicated to the 20-bit address bus, 21 physical wires dedicated to the control bus, and 15 physical wires dedicated to various power buses. Bus multiplexing requires fewer wires, which reduces costs in many early microprocessors and DRAM chips. One common multiplexing scheme, address multiplexing , has already been mentioned. Another multiplexing scheme re-uses

585-726: A card plugged into the bus, which is why computers have so many slots on the bus. But through the 1980s and 1990s, new systems like SCSI and IDE were introduced to serve this need, leaving most slots in modern systems empty. Today there are likely to be about five different buses in the typical machine, supporting various devices. "Third generation" buses have been emerging into the market since about 2001, including HyperTransport and InfiniBand . They also tend to be very flexible in terms of their physical connections, allowing them to be used both as internal buses, as well as connecting different machines together. This can lead to complex problems when trying to service different requests, so much of

650-436: A cartridge is less than that of an optical disc like a DVD-ROM or CD-ROM . Techniques such as bank switching were employed to be able to use cartridges with a capacity higher than the amount of memory directly addressable by the processor. As video games became more complex (and the size of their code grew), software manufacturers began sacrificing the quick load times of ROM cartridges in favor of greater storage capacity and

715-426: A cassette tape interface, 2 x joystick port, a parallel printer connector, an RF modulator output and a composite video output. The ROM cartridge allowed the user to easily use software such as video games. It supports four screen modes; 32x16 characters with 4 colors, 64x48 pixel graphics with 9 colors, 128x192 graphics with 4 colors, and 256x192 graphics with white and green colors. The Japanese version uses

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780-448: A custom " J-Cart " cartridge design by Codemasters which incorporated two additional gamepad ports. This allowed players to have up to four gamepads connected to the console without the need for an additional multi-controller adapter . Storing software on ROM cartridges has a number of advantages over other methods of storage like floppy disks and optical media . As the ROM cartridge

845-473: A form of flash memory technology similar to that of SD cards with larger storage space. As of 2024 , Nintendo is the only major company to exclusively use cartridges for their consoles and handhelds, as others such as Sony and Microsoft continue to use optical disc -based media for their consoles. In 1976 , 310,000 home video game cartridges were sold in the United States. Between 1983 and 2013,

910-710: A manufacturer of consumer electronics. They started manufacturing the PC-8001 and its peripherals which were developed by the Electronic Devices Group of Nippon Electric. It was successful and grew the personal computer market in Japan. They started developing a low-cost home computer, and it became the PC-6001 . At the same time, the Electronic Devices Group developed the PC-8801 for home and business, and

975-510: A multiplexed address scheme, the address is sent in two equal parts on alternate bus cycles. This halves the number of address bus signals required to connect to the memory. For example, a 32-bit address bus can be implemented by using 16 lines and sending the first half of the memory address, immediately followed by the second half memory address. Typically two additional pins in the control bus – row-address strobe (RAS) and column-address strobe (CAS) – are used to tell

1040-466: A passive backplane connected directly or through buffer amplifiers to the pins of the CPU . Memory and other devices would be added to the bus using the same address and data pins as the CPU itself used, connected in parallel. Communication was controlled by the CPU, which read and wrote data from the devices as if they are blocks of memory, using the same instructions, all timed by a central clock controlling

1105-506: A serial bus inherently has no timing skew or crosstalk. USB , FireWire , and Serial ATA are examples of this. Multidrop connections do not work well for fast serial buses, so most modern serial buses use daisy-chain or hub designs. The transition from parallel to serial buses was allowed by Moore's law which allowed for the incorporation of SerDes in integrated circuits which are used in computers. Network connections such as Ethernet are not generally regarded as buses, although

1170-449: A single source LRI/LRU or, as with ARINC 629, MIL-STD-1553B, and STANAG 3910, be duplex , allow all the connected LRI/LRUs to act, at different times ( half duplex ), as transmitters and receivers of data. The frequency or the speed of a bus is measured in Hz such as MHz and determines how many clock cycles there are per second; there can be one or more data transfers per clock cycle. If there

1235-719: A total of 2,910.72 million software cartridges had been sold for Nintendo consoles . ROM cartridges can not only carry software, but additional hardware expansions as well. Examples include various cartridge-based chips on the Super NES , the SVP chip in the Sega Genesis version of Virtua Racing , and a chess module in the Magnavox Odyssey² . Micro Machines 2 on the Genesis/Mega Drive used

1300-433: A unified system bus . In this case, a single mechanical and electrical system can be used to connect together many of the system components, or in some cases, all of them. Later computer programs began to share memory common to several CPUs. Access to this memory bus had to be prioritized, as well. The simple way to prioritize interrupts or bus access was with a daisy chain . In this case signals will naturally flow through

1365-412: Is a single transfer per clock cycle it is known as Single Data Rate (SDR), and if there are two transfers per clock cycle it is known as Double Data Rate (DDR) although the use of signalling other than SDR is uncommon outside of RAM. An example of this is PCIe which uses SDR. Within each data transfer there can be multiple bits of data. This is described as the width of a bus which is the number of bits

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1430-694: Is memory mapped into the system's normal address space, software stored in the ROM can be read like normal memory; since the system does not have to transfer data from slower media, it allows for nearly instant load time and code execution. Software run directly from ROM typically uses less RAM, leaving memory free for other processes. While the standard size of optical media dictates a minimum size for devices which can read discs, ROM cartridges can be manufactured in different sizes, allowing for smaller devices like handheld game systems . ROM cartridges can be damaged, but they are generally more robust and resistant to damage than optical media; accumulation of dirt and dust on

1495-475: Is provided by the bus‍—‌is not the case in many avionic systems , where data connections such as ARINC 429 , ARINC 629 , MIL-STD-1553B (STANAG 3838), and EFABus ( STANAG 3910 ) are commonly referred to as “data buses” or, sometimes, "databuses". Such avionic data buses are usually characterized by having several equipments or Line Replaceable Items/Units (LRI/LRUs) connected to a common, shared media . They may, as with ARINC 429, be simplex , i.e. have

1560-473: The IBM PC , although similar physical architecture can be employed, instructions to access peripherals ( in and out ) and memory ( mov and others) have not been made uniform at all, and still generate distinct CPU signals, that could be used to implement a separate I/O bus. These simple bus systems had a serious drawback when used for general-purpose computers. All the equipment on the bus had to talk at

1625-889: The S-100 bus were used, but to reduce latency , modern memory buses are designed to connect directly to DRAM chips, and thus are designed by chip standards bodies such as JEDEC . Examples are the various generations of SDRAM , and serial point-to-point buses like SLDRAM and RDRAM . An exception is the Fully Buffered DIMM which, despite being carefully designed to minimize the effect, has been criticized for its higher latency. Buses can be parallel buses , which carry data words in parallel on multiple wires, or serial buses , which carry data in bit-serial form. The addition of extra power and control connections, differential drivers , and data connections in each direction usually means that most serial buses have more conductors than

1690-467: The expansion bus , which in turn connects the computer to peripherals. Bus systems such as the SATA ports in modern computers support multiple peripherals, allowing multiple hard drives to be connected without an expansion card . In systems that have a similar architecture to multicomputers , but which communicate by buses instead of networks, the system bus is known as a front-side bus . In such systems,

1755-573: The 1980s, before Yamaha's Music Cartridge was introduced. Models that used these cartridges were in the Casiotone line of portable electronic keyboards. Amstrad Atari, Inc. Bandai Blaze Entertainment Coleco Fairchild Camera and Instrument Fisher-Price IBM Interton LeapFrog Magnavox / Philips Mattel Milton Bradley NEC Nikko Europe Nintendo Sega SNK Bus (computing) In computer architecture ,

1820-577: The 1980s, such as the DX1 , DX5 and DX7 and their PSR keyboard lineup in the mid-1990s, namely the PSR-320, PSR-420, PSR-520, PSR-620, PSR-330, PSR-530 and the PSR-6000 . These keyboards use specialized cards known as Music Cartridges , a ROM cartridge simply containing MIDI data to be played on the keyboard as MIDI sequence or song data. Casio has also used similar cartridges known as ROM Pack in

1885-506: The CPU could execute the program in place without having to first copy it into expensive RAM. The Texas Instruments TI-59 family of programmable scientific calculators used interchangeable ROM cartridges that could be installed in a slot at the back of the calculator. The calculator came with a module that provides several standard mathematical functions including the solution of simultaneous equations. Other modules were specialized for financial calculations, or other subject areas, and even

1950-469: The DRAM whether the address bus is currently sending the first half of the memory address or the second half. Accessing an individual byte frequently requires reading or writing the full bus width (a word ) at once. In these instances the least significant bits of the address bus may not even be implemented - it is instead the responsibility of the controlling device to isolate the individual byte required from

2015-472: The IEEE "Superbus" study group, the open microprocessor initiative (OMI), the open microsystems initiative (OMI), the "Gang of Nine" that developed EISA , etc. Early computer buses were bundles of wire that attached computer memory and peripherals. Anecdotally termed the " digit trunk " in the early Australian CSIRAC computer, they were named after electrical power buses, or busbars . Almost always, there

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2080-723: The Information Processing Group dealt with the 16-bit personal computer line. NEC Home Electronics discontinued development of the PC-6000 series, the PC-6600 series, and the PC-8000 series. These lines were merged to the PC-8800 series. The PC-6001 has the μPD780 processor (NEC clone of Zilog Z80 ), 16 KB RAM (up to 32 KB), General Instrument AY-3-8910 3-voice sound generator, a ROM Cartridge connector,

2145-457: The Information Processing Group developed the PC-9801 for business market. In 1983, New Nippon Electric changed its name to NEC Home Electronics. At that time, NEC group had four personal computer lines come out from different divisions. To avoid conflict, they decided to consolidate personal computer business into two divisions; NEC Home Electronics dealt with the 8-bit home computer line, and

2210-549: The address bus pins as the data bus pins, an approach used by conventional PCI and the 8086 . The various "serial buses" can be seen as the ultimate limit of multiplexing, sending each of the address bits and each of the data bits, one at a time, through a single pin (or a single differential pair). Over time, several groups of people worked on various computer bus standards, including the IEEE Bus Architecture Standards Committee (BASC),

2275-473: The addressable memory space is 4 GB. Early processors used a wire for each bit of the address width. For example, a 16-bit address bus had 16 physical wires making up the bus. As the buses became wider and lengthier, this approach became expensive in terms of the number of chip pins and board traces. Beginning with the Mostek 4096 DRAM , address multiplexing implemented with multiplexers became common. In

2340-411: The associated eSATA are one example of a system that would formerly be described as internal, while certain automotive applications use the primarily external IEEE 1394 in a fashion more similar to a system bus. Other examples, like InfiniBand and I²C were designed from the start to be used both internally and externally. An address bus is a bus that is used to specify a physical address . When

2405-489: The bits themselves, and allows for an increase in data transfer speed without increasing the frequency of the bus. The effective or real data transfer speed/rate may be lower due to the use of encoding that also allows for error correction such as 128/130b (b for bit) encoding. The data transfer speed is also known as the bandwidth. The simplest system bus has completely separate input data lines, output data lines, and address lines. To reduce cost, most microcomputers have

2470-493: The bus can transfer per clock cycle and can be synonymous with the number of physical electrical conductors the bus has if each conductor transfers one bit at a time. The data rate in bits per second can be obtained by multiplying the number of bits per clock cycle times the frequency times the number of transfers per clock cycle. Alternatively a bus such as PCIe can use modulation or encoding such as PAM4 which groups 2 bits into symbols which are then transferred instead of

2535-409: The bus had to talk at the same speed. While the CPU was now isolated and could increase speed, CPUs and memory continued to increase in speed much faster than the buses they talked to. The result was that the bus speeds were now much slower than what a modern system needed, and the machines were left starved for data. A particularly common example of this problem was that video cards quickly outran even

2600-519: The bus in physical or logical order, eliminating the need for complex scheduling. Digital Equipment Corporation (DEC) further reduced cost for mass-produced minicomputers , and mapped peripherals into the memory bus, so that the input and output devices appeared to be memory locations. This was implemented in the Unibus of the PDP-11 around 1969. Early microcomputer bus systems were essentially

2665-626: The bus supplied power, but often use a separate power source. This distinction is exemplified by a telephone system with a connected modem , where the RJ11 connection and associated modulated signalling scheme is not considered a bus, and is analogous to an Ethernet connection. A phone line connection scheme is not considered to be a bus with respect to signals, but the Central Office uses buses with cross-bar switches for connections between phones. However, this distinction‍—‌that power

PC-6000 series - Misplaced Pages Continue

2730-431: The cards to be much more complex. These buses also often addressed speed issues by being "bigger" in terms of the size of the data path, moving from 8-bit parallel buses in the first generation, to 16 or 32-bit in the second, as well as adding software setup (now standardised as Plug-n-play ) to supplant or replace the jumpers. However, these newer systems shared one quality with their earlier cousins, in that everyone on

2795-421: The cartridge contacts can cause problems, but cleaning the contacts with an isopropyl alcohol solution typically resolves the problems without risk of corrosion. ROM cartridges typically have less capacity than other media. The PCjr-compatible version of Lotus 1-2-3 comes on two cartridges and a floppy disk. ROM cartridges are typically more expensive to manufacture than discs, and storage space available on

2860-529: The cartridge was mapped into BIOS space). Some arcade system boards , such as Capcom 's CP System and SNK 's Neo Geo , also used ROM cartridges. Cassettes and floppy disks cost less than ROM cartridges and some memory cards were sold as an inexpensive alternative to ROM cartridges. A precursor to modern game cartridges of second generation video consoles was introduced with the first generation video game console Magnavox Odyssey in 1972, using jumper cards to turn on and off certain electronics inside

2925-527: The complete word transmitted. This is the case, for instance, with the VESA Local Bus which lacks the two least significant bits, limiting this bus to aligned 32-bit transfers. Historically, there were also some examples of computers which were only able to address words -- word machines . The memory bus is the bus which connects the main memory to the memory controller in computer systems . Originally, general-purpose buses like VMEbus and

2990-491: The computer into two "worlds", the CPU and memory on one side, and the various devices on the other. A bus controller accepted data from the CPU side to be moved to the peripherals side, thus shifting the communications protocol burden from the CPU itself. This allowed the CPU and memory side to evolve separately from the device bus, or just "bus". Devices on the bus could talk to each other with no CPU intervention. This led to much better "real world" performance, but also required

3055-700: The console. A modern take on game cartridges was invented by Wallace Kirschner, Lawrence Haskel and Jerry Lawson of Alpex Computer Corporation, first unveiled as part of the Fairchild Channel F home console in 1976. The cartridge approach gained more popularity with the Atari 2600 released the following year. From the late 1970s to mid-1990s, the majority of home video game systems were cartridge-based. As compact disc technology came to be widely used for data storage, most hardware companies moved from cartridges to CD-based game systems. Nintendo remained

3120-557: The data directly in memory, a concept known as direct memory access . Low-performance bus systems have also been developed, such as the Universal Serial Bus (USB). Given technological changes, the classical terms "system", "expansion" and "peripheral" no longer have the same connotations. Other common categorization systems are based on the bus's primary role, connecting devices internally or externally. However, many common modern bus systems can be used for both. SATA and

3185-489: The difference is largely conceptual rather than practical. An attribute generally used to characterize a bus is that power is provided by the bus for the connected hardware. This emphasizes the busbar origins of bus architecture as supplying switched or distributed power. This excludes, as buses, schemes such as serial RS-232 , parallel Centronics , IEEE 1284 interfaces and Ethernet, since these devices also needed separate power supplies. Universal Serial Bus devices may use

3250-486: The expansion bus may not share any architecture with their host CPUs, instead supporting many different CPUs, as is the case with PCI . While the term " peripheral bus " is sometimes used to refer to all other buses apart from the system bus, the "expansion bus" has also been used to describe a third category of buses separate from the peripheral bus, which includes bus systems like PCI. Early computer buses were parallel electrical wires with multiple hardware connections, but

3315-635: The input and output of a given bus. IBM introduced these on the IBM 709 in 1958, and they became a common feature of their platforms. Other high-performance vendors like Control Data Corporation implemented similar designs. Generally, the channel controllers would do their best to run all of the bus operations internally, moving data when the CPU was known to be busy elsewhere if possible, and only using interrupts when necessary. This greatly reduced CPU load, and provided better overall system performance. To provide modularity, memory and I/O buses can be combined into

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3380-404: The internal bus connecting the two being known as the system bus . In systems that include a cache , CPUs use high-performance system buses that operate at speeds greater than memory to communicate with memory. The internal bus (also known as the internal data bus, memory bus or system bus ) connects internal components of a computer to the mother board. Local buses connect the CPU and memory to

3445-559: The lone hold-out, using cartridges for their Nintendo 64 system; the company did not transition to optical media until the release of the GameCube in 2001. Cartridges were also used for their handheld consoles, which are known as Game Cards in the DS/3DS line of handhelds. These cartridges are much smaller and thinner than previous cartridges, and use the more modern flash memory for game data rather than built-in ROM chips on PCBs for

3510-556: The lower cost of optical media. Another source of pressure in this direction was that optical media could be manufactured in much smaller batches than cartridges; releasing a cartridge video game on the other hand inevitably includes the risk of producing thousands of unsold cartridges. Besides their prominent usage on video game consoles, ROM cartridges have also been used on a small number of electronic musical instruments, particularly electronic keyboards . Yamaha has made several models with such features, with their DX synthesizer in

3575-446: The minimum of one used in 1-Wire and UNI/O . As data rates increase, the problems of timing skew , power consumption, electromagnetic interference and crosstalk across parallel buses become more and more difficult to circumvent. One partial solution to this problem has been to double pump the bus. Often, a serial bus can be operated at higher overall data rates than a parallel bus, despite having fewer electrical connections, because

3640-401: The newer bus systems like PCI , and computers began to include AGP just to drive the video card. By 2004 AGP was outgrown again by high-end video cards and other peripherals and has been replaced by the new PCI Express bus. An increasing number of external devices started employing their own bus systems as well. When disk drives were first introduced, they would be added to the machine with

3705-484: The program attempted to perform those other tasks, it might take too long for the program to check again, resulting in loss of data. Engineers thus arranged for the peripherals to interrupt the CPU. The interrupts had to be prioritized, because the CPU can only execute code for one peripheral at a time, and some devices are more time-critical than others. High-end systems introduced the idea of channel controllers , which were essentially small computers dedicated to handling

3770-559: The same purpose. The release of the Nintendo Switch in 2017 marked the company's shift away from their own proprietary optical disc -based media after last using them in the Wii U in favor of small cartridge-based media. These cartridges are known as Game Cards like previous Nintendo handhelds, and are much smaller and thinner than previous cartridges for consoles as well as Nintendo's own Game Cards for their DS/3DS handhelds. It uses

3835-420: The same speed, as it shared a single clock. Increasing the speed of the CPU becomes harder, because the speed of all the devices must increase as well. When it is not practical or economical to have all devices as fast as the CPU, the CPU must either enter a wait state , or work at a slower clock frequency temporarily, to talk to other devices in the computer. While acceptable in embedded systems , this problem

3900-522: The speed of the CPU. Still, devices interrupted the CPU by signaling on separate CPU pins. For instance, a disk drive controller would signal the CPU that new data was ready to be read, at which point the CPU would move the data by reading the "memory location" that corresponded to the disk drive. Almost all early microcomputers were built in this fashion, starting with the S-100 bus in the Altair 8800 computer system. In some instances, most notably in

3965-593: The term is now used for any physical arrangement that provides the same logical function as a parallel electrical busbar . Modern computer buses can use both parallel and bit serial connections, and can be wired in either a multidrop (electrical parallel) or daisy chain topology, or connected by switched hubs. Many modern CPUs also feature a second set of pins similar to those for communicating with memory—but able to operate with different speeds and protocols—to ensure that peripherals do not slow overall system performance. CPUs can also feature smart controllers to place

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4030-436: The time around their release, ROM cartridges provided security against unauthorised copying of software. However, the manufacturing of ROM cartridges was more expensive than floppy disks, and the storage capacity was smaller. ROM cartridges and slots were also used for various hardware accessories and enhancements. The widespread usage of the ROM cartridge in video gaming applications has led it to be often colloquially called

4095-522: The work on these systems concerns software design, as opposed to the hardware itself. In general, these third generation buses tend to look more like a network than the original concept of a bus, with a higher protocol overhead needed than early systems, while also allowing multiple devices to use the bus at once. Buses such as Wishbone have been developed by the open source hardware movement in an attempt to further remove legal and patent constraints from computer design. The Compute Express Link (CXL)

4160-441: Was not tolerated for long in general-purpose, user-expandable computers. Such bus systems are also difficult to configure when constructed from common off-the-shelf equipment. Typically each added expansion card requires many jumpers in order to set memory addresses, I/O addresses, interrupt priorities, and interrupt numbers. "Second generation" bus systems like NuBus addressed some of these problems. They typically separated

4225-402: Was one bus for memory, and one or more separate buses for peripherals. These were accessed by separate instructions, with completely different timings and protocols. One of the first complications was the use of interrupts . Early computer programs performed I/O by waiting in a loop for the peripheral to become ready. This was a waste of time for programs that had other tasks to do. Also, if

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