TK 82C
Encyclopedia
TK 82C was a Sinclair ZX81
clone made by Microdigital Eletrônica Ltda.
, a computer company located in Brazil
.
SRAM
and 8 KB of EPROM
with the BASIC interpreter. The keyboard was made of layers of conductive (membrane) material and followed the Sinclair pattern. The video output was sent via a RF modulator
to a TV set tuned at VHF channel 3, and it featured black characters on a white background. The maximum resolution was 64 x 44 pixels black and white, for graphic plotting. There were some special characters (shade patterns) useful for games and basic images.
The TK 82C included the SLOW function which permitted the video be shown during the processing (the prior version, TK 82, a Sinclair ZX80
clone, ran only in fast mode, so the image was not shown during its processing). In reality, the SLOW function was done by an add-on board that was factory-mounted over the main board.
Although being a ZX81 clone, the TK 82C did not have the ULA chip from Ferranti, used in the former. Instead it was manufactured with a dozen of TTL
integrated circuits, which resulted in a somewhat large power consumption. This could be noted as the computer's case used to become quite hot after some minutes of operation.
Audio cables were supplied with the computer for connection with a regular tape recorder.
As the data encoding was entirely done by software, some hacks were made available to allow much faster transfers. Hi-fi recorders were required in order to use the greater speeds with a minimum of reliability.
In 1983, Sinclair Research sued Microdigital over copyright violation because of the unauthorized cloning of its product. Due to political trends from that time, the Brazilian court in charge of the case ended giving the win to Microdigital.
(a 16 KB RAM version with a case similar to ZX-Spectrum), more robust and with a better design.
Microdigital later produced the TK 90X
and TK 95
, which were clones of the ZX Spectrum
.
Sinclair ZX81
The ZX81 was a home computer produced by Sinclair Research and manufactured in Scotland by Timex Corporation. It was launched in the United Kingdom in March 1981 as the successor to Sinclair's ZX80 and was designed to be a low-cost introduction to home computing for the general public...
clone made by Microdigital Eletrônica Ltda.
Microdigital Eletronica
Microdigital Eletrônica Ltda. was an influential Brazilian computer company in the 1980s, based in São Paulo.- History :Established in 1981 by the brothers George and Tomas Kovari , its first product was the TK80, a clone of the British microcomputer Sinclair ZX80.The company...
, a computer company located in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
.
General information
The TK 82C had the ZILOG Z80A processor running at 3.25 MHz, 2 KBKilobyte
The kilobyte is a multiple of the unit byte for digital information. Although the prefix kilo- means 1000, the term kilobyte and symbol KB have historically been used to refer to either 1024 bytes or 1000 bytes, dependent upon context, in the fields of computer science and information...
SRAM
Static random access memory
Static random-access memory is a type of semiconductor memory where the word static indicates that, unlike dynamic RAM , it does not need to be periodically refreshed, as SRAM uses bistable latching circuitry to store each bit...
and 8 KB of EPROM
EPROM
An EPROM , or erasable programmable read only memory, is a type of memory chip that retains its data when its power supply is switched off. In other words, it is non-volatile. It is an array of floating-gate transistors individually programmed by an electronic device that supplies higher voltages...
with the BASIC interpreter. The keyboard was made of layers of conductive (membrane) material and followed the Sinclair pattern. The video output was sent via a RF modulator
RF modulator
An RF modulator is a device that takes a baseband input signal and outputs a radio frequency-modulated signal....
to a TV set tuned at VHF channel 3, and it featured black characters on a white background. The maximum resolution was 64 x 44 pixels black and white, for graphic plotting. There were some special characters (shade patterns) useful for games and basic images.
The TK 82C included the SLOW function which permitted the video be shown during the processing (the prior version, TK 82, a Sinclair ZX80
Sinclair ZX80
The Sinclair ZX80 is a home computer brought to market in 1980 by Science of Cambridge Ltd. . It is notable for being the first computer available in the United Kingdom for less than a hundred pounds...
clone, ran only in fast mode, so the image was not shown during its processing). In reality, the SLOW function was done by an add-on board that was factory-mounted over the main board.
Although being a ZX81 clone, the TK 82C did not have the ULA chip from Ferranti, used in the former. Instead it was manufactured with a dozen of TTL
TTL
TTL may refer to:* Taiwan Tobacco and Liquor, a state-owned manufacturer of cigarettes and alcohol in Taiwan* Through-the-lens metering, a feature of cameras capable of measuring light levels in a scene through their lens...
integrated circuits, which resulted in a somewhat large power consumption. This could be noted as the computer's case used to become quite hot after some minutes of operation.
Data Storage
Data storage was done in audio cassette tapes at 300 bits per second, and large programs could take up to 6 minutes to load.Audio cables were supplied with the computer for connection with a regular tape recorder.
As the data encoding was entirely done by software, some hacks were made available to allow much faster transfers. Hi-fi recorders were required in order to use the greater speeds with a minimum of reliability.
Accessories
- A 16 KB DRAMDramDram or DRAM may refer to:As a unit of measure:* Dram , an imperial unit of mass and volume* Armenian dram, a monetary unit* Dirham, a unit of currency in several Arab nationsOther uses:...
expansion was made available and, despite being optional, became a standard item. Soon after, a 48 KB expansion was also released, but due to pricing and the problematic data storage in cassettes, it never sold well.
- The TK 82C featured a DINDinDIN or Din or din can have several meanings:* A din is a loud noise.* Dīn, an Arabic term meaning "religion" or "way of life".* Din is one of the ten aspects of the Ein Sof in Kabbalah ....
connector for a joystick (in reality, it was wired to the keyboard matrix); Microdigital then marketed an Atari 2600Atari 2600The Atari 2600 is a video game console released in October 1977 by Atari, Inc. It is credited with popularizing the use of microprocessor-based hardware and cartridges containing game code, instead of having non-microprocessor dedicated hardware with all games built in...
joystick, accordingly retrofitted to match the DIN connector.
- A small printer, indeed a ZX PrinterZX PrinterThe Sinclair ZX Printer is a spark printer which was produced by Sinclair Research for its ZX81 home computer. It was launched in 1981, with a recommended retail price of £49.95....
clone, was announced for a long time by Microdigital, but was never released.
Compatibility and Legal Issues
All software designed to the ZX81 could run in the TK 82C with no problems, and vice-versa. So it was not uncommon to find software distributed in Brazil, that were nothing more than pirated copies of products for the ZX81. However, given the TK 82's popularity, a great deal of original software was developed in Brazil as well.In 1983, Sinclair Research sued Microdigital over copyright violation because of the unauthorized cloning of its product. Due to political trends from that time, the Brazilian court in charge of the case ended giving the win to Microdigital.
Later Products
The TK 82C (the C letter stands for "Científico", or Scientific in English) was replaced by the TK 83 (it used a ULA similar chip, as the original ZX81) and by the TK 85TK 85
The TK 85 was a ZX81 clone made by Microdigital Eletronica, a computer company located in Brazil. It came with 16 or 48 kB RAM, and had a ZX Spectrum-style case, more precisely a Timex Sinclair 1500 clone....
(a 16 KB RAM version with a case similar to ZX-Spectrum), more robust and with a better design.
Microdigital later produced the TK 90X
TK 90X
The TK 90X was the first Brazilian ZX Spectrum clone made in 1985 by Microdigital Eletronica, a company located at São Paulo, Brazil, that manufactured some ZX81 clones before and a ZX80 clones ....
and TK 95
TK 95
The TK 95 microcomputer was the evolution of TK 90X made in the 1980s by Microdigital Eletronica, a company located at São Paulo, Brazil that manufactured some ZX81 clones before and a ZX80 clone...
, which were clones of the ZX Spectrum
ZX Spectrum
The ZX Spectrum is an 8-bit personal home computer released in the United Kingdom in 1982 by Sinclair Research Ltd...
.