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86-739: The Datasette is probably the most sophisticated tape-storage method of any microcomputer. Typical compact cassette interfaces of the late 1970s use a small controller in the computer to convert digital data to and from analog audio tones. The interface connects to the cassette deck using normal audio cables like RCA jacks or 3.5mm phone jacks . Such a system is compatible with the Apple II and TRS-80 Color Computer , as well as many S-100 bus systems, and allows them to be used with any cassette player with suitable connections, but using analog tones—similar to how dial-up modems work—often results in read errors instead of successful loading of data. In

172-408: A 300 bit/s data rate. Once the bits can be decoded, they are fed into a shift register and are continuously compared to a special bit sequence. This bit sequence can also be seen as a byte. A bit-sequence match means that the stream is byte-synchronized. The first byte to compare with is called the lead-in byte . If matched, it's compared to the sync byte as well. An example: Turbo Tape 64 has

258-542: A conductor such as a wire, but can also flow through semiconductors , insulators , or even through a vacuum as in electron or ion beams . The electric current flows in a constant direction, distinguishing it from alternating current (AC). A term formerly used for this type of current was galvanic current . The abbreviations AC and DC are often used to mean simply alternating and direct , as when they modify current or voltage . Direct current may be converted from an alternating current supply by use of

344-553: A lead-in byte $ 02 (binary 00000010), sync byte $ 09 (binary 00001001) and a following sync sequence of $ 08, $ 07, $ 06, $ 05, $ 04, $ 03, $ 02, $ 01. There are at least four main models of the 1530/C2N Datassette: The first two external models were made as PET peripherals, and styled after the PET 2001 built-in tape drive. The latter two were styled and marketed for the VIC-20 and C64. All 1530s are compatible with all those computers, as well as

430-533: A phone connector converts the electrical signals to be read by the tape head, while mechanical gears simulate reel to reel movement without actual tapes when driven by the player mechanism. In order to wind up the tape more reliably, the former BASF (from 1998 EMTEC ) patented the Special Mechanism or Security Mechanism advertised with the abbreviation SM in the early 1970s, which was temporarily used under license by Agfa . This feature each includes

516-510: A rectifier , which contains electronic elements (usually) or electromechanical elements (historically) that allow current to flow only in one direction. Direct current may be converted into alternating current via an inverter . Direct current has many uses, from the charging of batteries to large power supplies for electronic systems, motors, and more. Very large quantities of electrical energy provided via direct-current are used in smelting of aluminum and other electrochemical processes. It

602-569: A 0.156-inch (4.0 mm)–spacing PCB edge connector at the computer end. All input/output signals to the Datasette are all digital, and so all digital-to-analog conversion , and vice versa, is handled within the unit. Power is also included in this cable. The pinout is ground, +5 V DC , motor, read, write, key-sense. The sense signal monitors the play, rewind, and fast-forward buttons but cannot differentiate between them. A mechanical interlock prevents any two of them from being pressed at

688-540: A C64/128 via an adaptor, which was supplied by Commodore with some units. The Datasette was more popular outside than inside the United States. U.S. Gold , which imported American computer games to Britain, often had to wait until they were converted from disk because most British Commodore 64 owners used tape, while the US magazine Compute!'s Gazette reported that by 1983 "90 percent of new Commodore 64 owners bought

774-543: A DC circuit. However, most such circuits have a DC solution. This solution gives the circuit voltages and currents when the circuit is in DC steady state . Such a circuit is represented by a system of differential equations . The solution to these equations usually contain a time varying or transient part as well as constant or steady state part. It is this steady state part that is the DC solution. There are some circuits that do not have

860-407: A DC solution. Two simple examples are a constant current source connected to a capacitor and a constant voltage source connected to an inductor. In electronics, it is common to refer to a circuit that is powered by a DC voltage source such as a battery or the output of a DC power supply as a DC circuit even though what is meant is that the circuit is DC powered. In a DC circuit, a power source (e.g.

946-444: A Datasette. In most parts of Europe, the Datasette was the medium of choice for several years after its launch, although floppy disk drives were generally available. The inexpensive and widely available audio cassettes made the Datasette a good choice for the budget-aware home computer mass market. Cassette tape The Compact Cassette , also commonly called a cassette tape , audio cassette , or simply tape or cassette ,

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1032-603: A US affiliate of Philips, introduced M.C. to the US in July 1966. The initial offering consisted of 49 titles. However, the system had been designed initially for dictation and portable use, with the audio quality of early players not well suited for music. Some early models also had an unreliable mechanical design. In 1971, the Advent Corporation introduced their Model 201 tape deck that combined Dolby type B noise reduction and chromium(IV) oxide (CrO 2 ) tape, with

1118-453: A battery system to ensure power is maintained for subscriber lines during power interruptions. Other devices may be powered from the telecommunications DC system using a DC-DC converter to provide any convenient voltage. Many telephones connect to a twisted pair of wires, and use a bias tee to internally separate the AC component of the voltage between the two wires (the audio signal) from

1204-423: A battery, capacitor, etc.) has a positive and negative terminal, and likewise, the load also has a positive and negative terminal. To complete the circuit, positive charges need to flow from the power source to the load. The charges will then return to the negative terminal of the load, which will then flow back to the negative terminal of the battery, completing the circuit. If either the positive or negative terminal

1290-609: A boom in bootleg cassettes made at live shows in the 1980s. The Walkman dominated the decade, selling up to 350 million units. So synonymous did the name "Walkman" become with all portable music players—with a German dictionary at one point defining the term as such without reference to Sony—that the Austrian Supreme Court ruled in 2002 that Sony, which had not sought to have the publisher of that dictionary retract that definition, could not prevent other companies from using that name, as it had now become genericized. As

1376-409: A cassette. Very simple cassette recorders for dictation purposes did not tightly control tape speed and relied on playback on a similar device to maintain intelligible recordings. For accurate reproduction of music, a tape transport incorporating a capstan and pinch roller system was used, to ensure tape passed over the record/playback heads at a constant speed. If the cassette is held with one of

1462-723: A commercial-grade tape transport mechanism supplied by the Wollensak camera division of 3M Corporation. This resulted in the format being taken more seriously for musical use, and started the era of high fidelity cassettes and players. British record labels began releasing compact cassettes in October 1967, and they exploded as a mass-market medium after the first Walkman , the TPS-L2, went on sale on 1 July 1979, as cassettes provided portability, which vinyl records could not. While portable radios and boom boxes had been around for some time,

1548-399: A continuation of the increasingly slower speed series in open-reel machines operating at 30, 15, 7 + 1 ⁄ 2 , or 3 + 3 ⁄ 4 inches per second. For comparison, the typical open-reel 1 ⁄ 4 -inch 4-track consumer format used tape that is 0.248 inches (6.3 mm) wide, each track .043 in (1.1 mm) wide, and running at either twice or four times the speed of

1634-540: A continuous demand for English language cassettes, as of 2011, due to the affordable cost. National Audio Company in Missouri, the largest of the few remaining manufacturers of audio cassettes in the US, oversaw the mass production of the "Awesome Mix #1" cassette from the film Guardians of the Galaxy in 2014. They reported that they had produced more than 10 million tapes in 2014 and that sales were up 20 percent

1720-524: A direct current source . The DC solution of an electric circuit is the solution where all voltages and currents are constant. Any stationary voltage or current waveform can be decomposed into a sum of a DC component and a zero-mean time-varying component; the DC component is defined to be the expected value, or the average value of the voltage or current over all time. Although DC stands for "direct current", DC often refers to "constant polarity". Under this definition, DC voltages can vary in time, as seen in

1806-597: A disk drive with their computer". Computer Gaming World reported in 1986 that British cassette-based software had failed in the United States because "97% of the Commodore systems in the USA have disk drives"; by contrast, MicroProse reported in 1987 that 80% of its 100,000 sales of Gunship in the UK were on cassette. In the United States disk drives quickly became standard, despite the 1541 costing roughly five times as much as

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1892-437: A double-coating technique to enhance overall tape output levels. This product was marketed as "High Energy" under its Scotch brand of recording tapes. Inexpensive cassettes commonly are labeled "low-noise", but typically are not optimized for high frequency response . For this reason, some low-grade IEC Type I tapes have been marketed specifically as better suited for data storage than for sound recording. In 1968, DuPont ,

1978-501: A foothold for Western culture among the younger generations. Likewise, in Egypt cassettes empowered an unprecedented number of people to create culture, circulate information, and challenge ruling regimes before the internet became publicly accessible. One of the political uses of cassette tapes was the dissemination of sermons by the exiled Ayatollah Khomeini throughout Iran before the 1979 Iranian Revolution , in which Khomeini urged

2064-421: A handler code, or simply discovered by testing bit 4 of location $ DC0D. The points that trigger this event are indicated by the black circles in the figure. Inside the tape device the read head signal is fed into an operational amplifier (1) whose output signal is DC -filtered. Op-amp (2) amplifies and feeds an RC filter. Op-amp (3) amplifies the signal again followed by another DC filter. Op-amp (4) amplifies

2150-410: A large margin. Philips was competing with Telefunken and Grundig (with their DC International format ) in a race to establish its cassette tape as the worldwide standard, and it wanted support from Japanese electronics manufacturers. Philips' Compact Cassette became dominant as a result of Sony pressuring Philips to license the format to them free of charge. In the early years sound quality

2236-419: A lesser extent in hardcore punk , death metal , and black metal circles, out of a fondness for the format. Even among major-label stars, the form has at least one devotee: Thurston Moore stated in 2009, "I only listen to cassettes." By 2019, few companies still made cassettes. Among those are National Audio Company, from the US, and Mulann, also known as Recording The Masters, from France. Sony announced

2322-456: A period in the 1990s. Another barrier to cassettes overtaking vinyl in sales was shoplifting ; compact cassettes were small enough that a thief could easily place one inside a pocket and walk out of a shop without being noticed. To prevent this, retailers in the US would place cassettes inside oversized "spaghetti box" containers or locked display cases , either of which would significantly inhibit browsing, thus reducing cassette sales. During

2408-458: A rail to guide the tape to the spool and prevent an unclean roll from forming. Magnetic tape is not an ideal medium for long-term archival storage, as it begins to degrade after 10 – 20 years, with some experts estimating its lifespan to be no more than 30 years. Direct current Direct current ( DC ) is one-directional flow of electric charge . An electrochemical cell is a prime example of DC power. Direct current may flow through

2494-460: A result of this, a number of Sony's competitors produced their own version of the Walkman. Others made their own branded tape players, like JVC, Panasonic, Sharp, and Aiwa, the second-largest producer of the devices. Between 1985, when cassettes overtook vinyl, and 1992, when they were overtaken by CDs (introduced in 1983 as a format that offered greater storage capacity and more accurate sound),

2580-522: A small case (cartridge)—hence "cassette". These spools and their attendant parts are held inside a protective plastic shell which is 4 by 2.5 by 0.5 inches (10.2 cm × 6.35 cm × 1.27 cm) at its largest dimensions. The tape itself is commonly referred to as "eighth-inch" tape, supposedly 1 ⁄ 8 inch (0.125 in; 3.17 mm) wide, but actually slightly larger, at 0.15 inches (3.81 mm). Two stereo pairs of tracks (four total) or two monaural audio tracks are available on

2666-456: A trend that continued in 2017 and 2018. In the UK, sales of cassette tapes in 2021 reached its highest number since 2003. Cassettes are favored by some artists and listeners, including those of older genres of music such as dansband , as well as independent and underground artists , some of whom were releasing new music on tape by the 2020s, including Britney Spears and Busta Rhymes . Reasons cited for this include tradition, low cost,

Commodore Datasette - Misplaced Pages Continue

2752-414: Is 0.15 in (3.81 mm) wide, with each mono track 1.5 millimetres (0.059 in) wide, plus an unrecorded guard band between each track. In stereo, each track is further divided into a left and a right channel of 0.6 mm (0.024 in) each, with a gap of 0.3 mm (0.012 in). The tape moves past the playback head at 1 + 7 ⁄ 8 inches per second (4.76 cm/s), the speed being

2838-591: Is 3.8 mm. For mono recording the track width is 1.5 mm. In stereo mode each channel has width of 0.6 mm with a 0.3 mm separation to avoid crosstalk . The head-gap width is 2 μm which gives a theoretical maximum frequency of about 12 kHz (at the standard speed of 1 7/8 ips or 4.76 cm/s). A narrower gap would give a higher frequency limit but also weaker magnetization. Cassette tape adapters allow external audio sources to be played back from any tape player, but were typically used for car audio systems. An attached audio cable with

2924-554: Is also used for some railways , especially in urban areas . High-voltage direct current is used to transmit large amounts of power from remote generation sites or to interconnect alternating current power grids. Direct current was produced in 1800 by Italian physicist Alessandro Volta 's battery, his Voltaic pile . The nature of how current flowed was not yet understood. French physicist André-Marie Ampère conjectured that current travelled in one direction from positive to negative. When French instrument maker Hippolyte Pixii built

3010-578: Is an analog magnetic tape recording format for audio recording and playback . Invented by Lou Ottens and his team at the Dutch company Philips , the Compact Cassette was released in August 1963. Compact Cassettes come in two forms, either containing content as a prerecorded cassette ( Musicassette ), or as a fully recordable "blank" cassette. Both forms have two sides and are reversible by

3096-482: Is an AC device which uses a rectifier to produce DC for battery charging. Most highway passenger vehicles use nominally 12  V systems. Many heavy trucks, farm equipment, or earth moving equipment with Diesel engines use 24 volt systems. In some older vehicles, 6 V was used, such as in the original classic Volkswagen Beetle . At one point a 42 V electrical system was considered for automobiles, but this found little use. To save weight and wire, often

3182-435: Is commonly found in many extra-low voltage applications and some low-voltage applications, especially where these are powered by batteries or solar power systems (since both can produce only DC). Most electronic circuits or devices require a DC power supply . Domestic DC installations usually have different types of sockets , connectors , switches , and fixtures from those suitable for alternating current. This

3268-427: Is disconnected, the circuit will not be complete and the charges will not flow. In some DC circuit applications, polarity does not matter, which means you can connect positive and negative backwards and the circuit will still be complete and the load will still function normally. However, in most DC applications, polarity does matter, and connecting the circuit backwards will result in the load not working properly. DC

3354-412: Is distributed to a substation, which utilizes a rectifier to convert the power to direct current. The term DC is used to refer to power systems that use only one electrical polarity of voltage or current, and to refer to the constant, zero-frequency, or slowly varying local mean value of a voltage or current. For example, the voltage across a DC voltage source is constant as is the current through

3440-447: Is mostly due to the lower voltages used, resulting in higher currents to produce the same amount of power . It is usually important with a DC appliance to observe polarity, unless the device has a diode bridge to correct for this. Most automotive applications use DC. An automotive battery provides power for engine starting, lighting, the ignition system, the climate controls, and the infotainment system among others. The alternator

3526-767: The Berlin Radio Show , and in the United States (under the Norelco brand) in November 1964. The trademark name Compact Cassette came a year later. The team of Dutch and Belgian origin at Philips was led by the Dutch Lou Ottens in Hasselt , Belgium. Philips also offered a machine to play and record the cassettes, the Philips Typ EL 3300 . An updated model, Typ EL 3301 was offered in

Commodore Datasette - Misplaced Pages Continue

3612-616: The C128 . In addition to this, some models came with a small hole above the keys, to allow access to the adjustment screw of the tape head azimuth position. A small screwdriver can thus easily be used to affect the adjustment without disassembling the Datassette's chassis. Confusingly, the Datassette at various times was sold both as the C2N DATASETTE UNIT Model 1530 and as the 1530 DATASSETTE UNIT Model C2N . Note

3698-494: The DIY ease of use, and a nostalgic fondness for how the format's imperfections lend greater vibrancy to low-fi, experimental music, despite the lack of the "full-bodied richness" of vinyl. Cassette tapes are made of a polyester-type plastic film with a magnetic coating. The original magnetic material was based on gamma ferric oxide (Fe 2 O 3 ). Circa 1970, 3M Company developed a cobalt volume-doping process combined with

3784-765: The Revolutionary Left Movement (MIR) made use of cassettes to spread their messages. Cassette technology was a booming market for pop music in India , drawing criticism from conservatives while at the same time creating a huge market for legitimate recording companies, as well as pirated tapes. Some sales channels were associated with cassettes: in Spain filling stations often featured a display selling cassettes. While offering also mainstream music these cassettes became associated with genres such as Gipsy rhumba , light music and joke tapes that were common in

3870-446: The 1970s and 1980s. Despite sales of CDs overtaking those of prerecorded cassettes in the early 1990s in the U.S., the format remained popular for specific applications, such as car audio , personal stereos , boomboxes , telephone answering machines , dictation , field recording , home recording , and mixtapes well into the decade. Cassette players were typically more resistant to shocks than CD players, and their lower fidelity

3956-448: The DC component of the voltage between the two wires (used to power the phone). High-voltage direct current (HVDC) electric power transmission systems use DC for the bulk transmission of electrical power, in contrast with the more common alternating current systems. For long-distance transmission, HVDC systems may be less expensive and suffer lower electrical losses. Applications using fuel cells (mixing hydrogen and oxygen together with

4042-679: The Datasette's launch, however, special turbo tape software appeared, providing much faster loading and saving. Such software was integrated into most commercial prerecorded applications (mostly games), as well as being available separately for loading and saving the users' homemade programs and data. These programs were only widely used in Europe, as the US market had long since moved onto disks. Datasettes can typically store about 100 kByte per 30 minute side. The use of turbo tape and other fast loaders increased this number to roughly 1000 kByte . The Datasette has only one connection cable, with

4128-466: The Datasette, instead of writing two tones to tape to indicate bits, patterns of square waves are used, including a parity bit . Programs are written twice to tape for error correction ; if an error is detected when reading the first recording, the computer corrects it with data from the second. The Datasette has built-in analog-to-digital converters and audio filters to convert the computer's digital data into analog audio and vice versa. Connection to

4214-509: The US dropped from 442 million in 1990 to 274,000 by 2007. For audiobooks , the final year that cassettes represented more than 50% of total market sales was 2002 when they were replaced by CDs as the dominant media. The last new car with an available cassette player was a 2014 TagAZ AQUiLA. Four years prior, Sony had stopped the production of personal cassette players. In 2011, the Oxford English Dictionary removed

4300-422: The US in November 1964 as Norelco Carry-Corder 150 . By 1966 over 250,000 recorders had been sold in the US alone and Japan soon became the major source of recorders. By 1968, 85 manufacturers had sold over 2.4 million players. By the end of the 1960s, the cassette business was worth an estimated 150 million dollars. By the early 1970s the compact cassette machines were outselling other types of tape machines by

4386-483: The Walkman was the first truly personal portable music player, one that not only allowed users to listen to music away from home, but to do so in private. According to the technology news website The Verge, "the world changed" on the day the TPS-L2 was released. Stereo tape decks and boom boxes became some of the most highly sought-after consumer products of both decades, as the ability of users to take their music with them anywhere with ease led to its popularity around

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4472-471: The cassette shell indicate the type of tape. Type I cassettes have only write-protect notches, Type II have an additional pair next to the write protection ones, and Type IV (metal) have a third set near the middle of the top of the cassette shell. These allow later cassette decks to detect the tape type automatically and select the proper bias and equalization. The cassette was the next step following reel-to-reel audio tape recording , although, because of

4558-444: The cassette tape was the most popular format in the United States and the UK. Record labels experimented with innovative packaging designs. A designer during the era explained: "There was so much money in the industry at the time, we could try anything with design." The introduction of the cassette single , called a "cassingle", was also part of this era and featured a music single in Compact Cassette form. Until 2005, cassettes remained

4644-407: The circuit voltages and currents are independent of time. A particular circuit voltage or current does not depend on the past value of any circuit voltage or current. This implies that the system of equations that represent a DC circuit do not involve integrals or derivatives with respect to time. If a capacitor or inductor is added to a DC circuit, the resulting circuit is not, strictly speaking,

4730-501: The computer is done via a proprietary edge connector (Commodore 1530) or mini-DIN connector (1531). The absence of recordable audio signals on this interface makes the Datasette and clones the only cassette recorders usable with Commodore computers, until aftermarket converters made the use of ordinary recorders possible. Because of its digital format the Datasette is both more reliable than other data cassette systems and very slow, transferring data at around 50 bytes per second. After

4816-595: The difference in spelling (one S versus two) used on the original product packaging. Like Datasette models, the recording format is compatible across computers; the VIC, for example, can read PET cassettes. Similar in physical appearance to the 1530/C2N models is the Commodore 1531 , made for the Commodore 16 and Plus/4 series computers. This has a Mini-DIN connector in place of the PCB edge connector. This can be used with

4902-484: The dominant medium for purchasing and listening to music in some developing countries , but compact disc (CD) technology had superseded the Compact Cassette in the vast majority of music markets throughout the world by this time. Compact cassettes served as catalysts for social change. Their small size, durability and ease of copying helped bring underground rock and punk music behind the Iron Curtain , creating

4988-642: The early '70s. By 1968, 85 manufacturers had sold over 2.4 million mono and stereo players. By the end of the 1960s, the cassette business was worth an estimated 150 million dollars. By the early 1970s the compact cassette machines were outselling other types of tape machines by a large margin. The mass production of "blank" (not yet recorded) Compact Cassettes began in 1964 in Hanover , Germany. Prerecorded music cassettes (also known as Music-Cassettes , and later just Musicassettes ; M.C. for short) were launched in Europe in late 1965. The Mercury Record Company ,

5074-502: The early 1960s Philips Eindhoven tasked two different teams to design a tape cartridge for thinner and narrower tape compared to what was used in reel-to-reel tape recorders. By 1962, the Vienna division of Philips developed a single-hole cassette , adapted from its German described name Einloch-Kassette . Philips selected the two-spool cartridge as a winner and introduced the 2-track 2-direction mono version in Europe on 28 August 1963 at

5160-443: The early 1980s some record labels sought to solve this problem by introducing new, larger packages for cassettes which would allow them to be displayed alongside vinyl records and compact discs , or giving them a further market advantage over vinyl by adding bonus tracks . Willem Andriessen wrote that the development in technology allowed "hardware designers to discover and satisfy one of the collective desires of human beings all over

5246-442: The end of cassette Walkman production on 22 October 2010, a result of the emergence of MP3 players such as Apple's iPod. As of 2022, Sony uses the Walkman brand solely for its line of digital media players. In 2010, Botswana-based Diamond Studios announced plans for establishing a plant to mass-produce cassettes in a bid to combat piracy. It opened in 2011. In South Korea, the early English education boom for toddlers encourages

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5332-654: The first dynamo electric generator in 1832, he found that as the magnet used passed the loops of wire each half turn, it caused the flow of electricity to reverse, generating an alternating current . At Ampère's suggestion, Pixii later added a commutator , a type of "switch" where contacts on the shaft work with "brush" contacts to produce direct current. The late 1870s and early 1880s saw electricity starting to be generated at power stations . These were initially set up to power arc lighting (a popular type of street lighting) running on very high voltage (usually higher than 3,000 volts) direct current or alternating current. This

5418-520: The following year, their best year since they opened in 1969. In 2016, cassette sales in the United States rose by 74% to 129,000. In 2018, following several years of shortage, National Audio Company began producing their own magnetic tape, becoming the world's first known manufacturer of an all-new tape stock. Mulann, a company which acquired Pyral/RMGI in 2015 and originates from BASF , also started production of its new cassette tape stock in 2018, basing on reel tape formula. In Japan and South Korea,

5504-459: The globe. Like the transistor radio in the 1950s and 1960s, the portable CD player in the 1990s, and the MP3 player in the 2000s, the Walkman defined the portable music market for the decade of the '80s, with cassette sales overtaking those of LPs . Total vinyl record sales remained higher well into the 1980s due to greater sales of singles, although cassette singles achieved popularity for

5590-404: The inventor of a chromium dioxide (CrO 2 ) manufacturing process, began commercialization of CrO 2 media. The first CrO 2 cassette was introduced in 1970 by Advent , and later strongly backed by BASF , the inventor and longtime manufacturer of magnetic recording tape. Next, coatings using magnetite (Fe 3 O 4 ) such as TDK 's Audua were produced in an attempt to approach or exceed

5676-1124: The labels facing the user and the tape opening at the bottom, the write-protect notch for the corresponding side is at the top-left. Tape length usually is measured in minutes of total playing time. Many of the varieties of blank tape were C60 (30 minutes per side), C90 (45 minutes per side) and C120 (60 minutes per side). Maxell makes 150-minute cassettes (UR-150) - 75 minutes per side. The C46 and C60 lengths typically are 15 to 16 micrometers (0.59 to 0.63 mils) thick, but C90s are 10 to 11 μm (0.39 to 0.43 mils) and (the less common) C120s are just 6 μm (0.24 mils) thick, rendering them more susceptible to stretching or breakage. Even C180 tapes were available at one point. Other lengths are (or were) also available from some vendors, including C10, C12 and C15 (useful for saving data from early home computers and in telephone answering machines ), C30, C40, C50, C54, C64, C70, C74, C80, C84, C94, C100, C105, C110, and C150. As late as 2010, Thomann still offered C10, C20, C30 and C40 IEC Type II tape cassettes for use with 4- and 8-track portastudios . The full tape width

5762-438: The limitations of the cassette's size and speed, it initially compared poorly in quality. Unlike the 4-track stereo open-reel format, the two stereo tracks of each side lie adjacent to each other, rather than being interleaved with the tracks of the other side. This permitted monaural cassette players to play stereo recordings "summed" as mono tracks and permitted stereo players to play mono recordings through both speakers. The tape

5848-458: The lower amplitude for the shorter periods. A circuit in the tape unit transforms the analog signal into a logical 1 or 0, which is then transmitted to the computer via the tape connector . Inside the computer, the first Complex Interface Adapter (6526) in the C64 senses when the signal goes from one to zero. This event is called trigger and causes an interrupt request . This event can be handled by

5934-453: The market that use a pure (CrO 2 ) coating. Simple voice recorders and earlier cassette decks are designed to work with standard ferric formulations. Newer tape decks usually are built with switches and later detectors for the different bias and equalization requirements for higher grade tapes. The most common are iron oxide tapes (as defined by the IEC 60094 standard ). Notches on top of

6020-512: The metal frame of the vehicle is connected to one pole of the battery and used as the return conductor in a circuit. Often the negative pole is the chassis "ground" connection, but positive ground may be used in some wheeled or marine vehicles. In a battery electric vehicle , there are usually two separate DC systems. The "low voltage" DC system typically operates at 12V, and serves the same purpose as in an internal combustion engine vehicle. The "high voltage" system operates at 300-400V (depending on

6106-530: The overthrow of the regime of the Shah , Mohammad Reza Pahlavi . During the military dictatorship of Chile (1973–1990) a "cassette culture" emerged where blacklisted music or music that was by other reasons not available as records was shared. Some pirate cassette producers created brands such as Cumbre y Cuatro that have in retrospect received praise for their contributions to popular music. Armed groups such as Manuel Rodríguez Patriotic Front (FPMR) and

6192-563: The phrase "cassette player" from its 12th edition Concise version, which prompted some media sources to mistakenly report that the term "cassette tape" was being removed. In India, music continued to be released on the cassette format due to its low cost until 2009. Although portable digital recorders are most common today, analog tape remains a desirable option for certain artists and consumers. Underground and DIY communities release regularly, and sometimes exclusively, on cassette format, particularly in experimental music circles and to

6278-593: The pop acts Seiko Matsuda , SHINee , and NCT 127 released their material on limited-run cassettes. In Reiwa era Japan, the revived popularity of cassette tapes is an example of Showa retro . In the mid-to-late 2010s, cassette sales saw a modest resurgence concurrent with the vinyl revival . As early as 2015, the retail chain Urban Outfitters , which had long sold LPs , started selling new pre-recorded cassettes (both new and old albums), blank cassettes, and players. In 2016, cassette sales increased,

6364-428: The raw output of a rectifier or the fluctuating voice signal on a telephone line. Some forms of DC (such as that produced by a voltage regulator ) have almost no variations in voltage , but may still have variations in output power and current. A direct current circuit is an electrical circuit that consists of any combination of constant voltage sources, constant current sources, and resistors . In this case,

6450-411: The same time. The motor power is derived from the computer's unregulated 9 V DC supply via a transistor circuit. To record physical data, the zero-crossing from positive to negative voltage of the analog signal is measured. The resulting time between these positive to negative crossings is then compared to a threshold to determine whether the time since the last crossing is short (0) or long (1). Note

6536-616: The signal into clipping the sine -formed signal. The positive and negative rails for all op-amps are wired to +5V DC and GND . The clipped signal therefore fits into the TTL electrical level window of the Schmitt trigger step that in turn feeds the digital cassette port. On the PAL version of the C64, the time granularity is 1.014 μs (for NTSC 0.978 μs ). Since each bit uses 3284 clock cycles this means 3284 * 1.014 μs = 3330 μs/bit. or

6622-482: The sound quality of vinyl records . Cobalt - adsorbed iron oxide (Avilyn) was introduced by TDK in 1974 and proved very successful. "Type IV" tapes using pure metal particles (as opposed to oxide formulations) were introduced in 1979 by 3M under the trade name Metafine. The tape coating on most cassettes sold as of 2024 are either "normal" or "chrome" consists of ferric oxide and cobalt mixed in varying ratios (and using various processes); there are very few cassettes on

6708-536: The tape; one stereo pair or one monophonic track is played or recorded when the tape is moving in one direction and the second (pair) when moving in the other direction. This reversal is achieved either by manually flipping the cassette when the tape comes to an end, or by the reversal of tape movement, known as "auto-reverse", when the mechanism detects that the tape has ended. After the Second World War , magnetic tape recording technology proliferated across

6794-518: The user. Although other tape cassette formats have also existed—for example the Microcassette —the generic term cassette tape is normally used to refer to the Compact Cassette because of its ubiquity. Compact Cassettes contain two miniature spools, between which the magnetically coated, polyester -type plastic film (magnetic tape) is passed and wound —essentially miniaturizing reel-to-reel audio tape and enclosing it, with its reels, in

6880-464: The vehicle), and provides the power for the traction motors . Increasing the voltage for the traction motors reduces the current flowing through them, increasing efficiency. Telephone exchange communication equipment uses standard −48 V DC power supply. The negative polarity is achieved by grounding the positive terminal of power supply system and the battery bank. This is done to prevent electrolysis depositions. Telephone installations have

6966-559: The world, independent of region, climate, religion, culture, race, sex, age and education: the desire to enjoy music at any time, at any place, in any desired sound quality and almost at any wanted price". Critic Robert Palmer , writing in The New York Times in 1981, cited the proliferation of personal stereos as well as extra tracks not available on LP as reasons for the surge in popularity of cassettes. Cassettes' ability to allow users to record content in public also led to

7052-513: The world. In the United States, Ampex , using equipment obtained in Germany as a starting point, began commercial production of tape recorders . First used in studios to record radio programs, tape recorders quickly found their way into schools and homes. By 1953, 1 million US homes had tape machines. In 1958, following four years of development, RCA Victor introduced the stereo, quarter-inch, reversible, reel-to-reel RCA tape cartridge . In

7138-406: Was followed by the widespread use of low voltage direct current for indoor electric lighting in business and homes after inventor Thomas Edison launched his incandescent bulb based electric " utility " in 1882. Because of the significant advantages of alternating current over direct current in using transformers to raise and lower voltages to allow much longer transmission distances, direct current

7224-413: Was mediocre, but it improved dramatically by the early 1970s when it caught up with the quality of 8-track tape and kept improving. The Compact Cassette went on to become a popular (and re-recordable ) alternative to the 12-inch vinyl LP during the late 1970s. As with prerecorded reel-to-reel and 8-track, sales were slow to start, but picked up rapidly to tie with the 8-track before superseding it by

7310-501: Was not considered a serious drawback in mobile use. With the introduction of electronic skip protection it became possible to use portable CD players on the go, and automotive CD players became viable. CD-R drives and media also became affordable for consumers around the same time. By 1993, annual shipments of CD players had reached 5 million, up 21% from the year before; while cassette player shipments had dropped 7% to approximately 3.4 million. Sales of pre-recorded music cassettes in

7396-477: Was replaced over the next few decades by alternating current in power delivery. In the mid-1950s, high-voltage direct current transmission was developed, and is now an option instead of long-distance high voltage alternating current systems. For long distance undersea cables (e.g. between countries, such as NorNed ), this DC option is the only technically feasible option. For applications requiring direct current, such as third rail power systems, alternating current

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