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{{Short description|ZX81 clone made by Microdigital Eletrônica in 1981}}
{{Infobox information appliance
| name = TK82C
| image = TK82C Microdigital Eletrônica.jpg
| caption = 
| developer = [[Microdigital Eletronica|Microdigital Eletrônica]]
| manufacturer = [[Microdigital Eletronica|Microdigital Eletrônica]]
| type = [[Home computer]]
| releasedate = {{Start date and age|1983}}
| price = 
| discontinued = 
| os = [[Sinclair BASIC#8K BASIC|8K Sinclair BASIC]]
| power = 9V DC
| cpu = [[Zilog Z80|Z80A]]
| memory = 2&nbsp;[[kilobyte|KB]] [[Static random access memory|SRAM]] and 8&nbsp;KB of [[EPROM]]
| predecessor = [[TK82]]
| successor = [[TK83]], [[TK85]]
| related = [[TK90X]]
| compatibility = [[ZX81]]
| graphics = TTL integrated circuits
| memory card = External Compact Cassette recorder at 300 bps
| display = Monochrome display on television; 24 lines × 32 characters or
64 × 48 pixels graphics mode
| CPUspeed = 3.25&nbsp;MHz
}}

'''TK82C''' was a [[Sinclair ZX81]] clone made by [[Microdigital Eletronica|Microdigital Eletrônica Ltda.]], a computer company located in [[Brazil]].<ref>{{Cite web |last=Pinheiro |first=Ricardo |date=2015-02-19 |title=Link do dia: TK-82C by Victor Trucco |url=https://retropolis.com.br/2015/02/19/link-do-dia-tk-82c-by-victor-trucco/ |access-date=2023-01-19 |website=Retrópolis |language=pt-BR}}</ref><ref>{{Cite web |last=Trucco |first=Victor |date=2019 |title=O TK82-C |url=https://www.victortrucco.com/TK/TK82C/TK82C |access-date=2023-01-19 |website=victortrucco.com}}</ref><ref>{{Cite web |title=TK-82C Microdigital Eletronica Ltda (Brazil) |url=https://www.1000bit.it/scheda.asp?id=1578 |access-date=2023-01-19 |website=1000 BiT}}</ref><ref>{{Cite web |date=2000 |title=Microdigital TK 82, TK 82C |url=https://www.museo8bits.com/tk82.htm |access-date=2023-01-19 |website=El Museo de los 8 Bits}}</ref>

==General information==

The TK82C had the [[Zilog Z80|Zilog Z80A]] processor running at 3.25&nbsp;MHz, 2&nbsp;[[kilobyte|KB]] [[Static random access memory|SRAM]] and 8&nbsp;KB of [[EPROM]] with the [[BASIC programming language|BASIC]] interpreter. The C letter stands for "Científico", or "Scientific" in English.

The keyboard was made of layers of conductive (membrane) material and followed the Sinclair layout. The video output was sent via a [[RF modulator]] to a TV set tuned at [[VHF]] channel 3, and featured black characters on a white background. The maximum resolution was 64 x 44 [[pixels]], based on [[Semigraphics|semigraphic]] characters useful for games and basic images (see [[ZX81 character set]]).

The TK82C included the <code>SLOW</code> function, which permitted the video be shown during the processing (the prior version, [[TK82]], a [[Sinclair ZX80]] clone, ran only in fast mode, so the image was not shown during its processing). In reality, the <code>SLOW</code> function was done by an add-on board that was factory-mounted over the main board.

Although being a ZX81 clone, the TK82C did not have the [[Uncommitted Logic Array|ULA]] chip from [[Ferranti]], used in the former. Instead it was manufactured with a dozen of [[Transistor–transistor logic|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.

==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 [[DRAM]] 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 TK82C featured a [[DIN]] connector for a joystick (in reality, it was wired to the keyboard matrix); Microdigital then marketed an [[Atari 2600]] joystick, accordingly retrofitted to match the DIN connector.
* A small printer, indeed a [[ZX Printer]] 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 TK82C with no problems, and vice versa. So it was not uncommon to find software distributed in Brazil, that were nothing more than illegitimate copies of products for the ZX81. However, given the TK82'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 sided with Microdigital.<ref>{{Cite book |last=Lupi |first=André Lipp Pinto Basto |url=https://egov.ufsc.br/portal/conteudo/prote%C3%A7%C3%A3o-jur%C3%ADdica-dos-direitos-de-propriedade-intelectual-sobre |title=Proteção jurídica dos direitos de propriedade intelectual sobre softwares: eficácia e adequação |year=1997|archive-url=https://web.archive.org/web/20220716165739/https://egov.ufsc.br/portal/conteudo/prote%C3%A7%C3%A3o-jur%C3%ADdica-dos-direitos-de-propriedade-intelectual-sobre |archive-date=2022-07-16 }}</ref>

==Later Products==

The TK82C was replaced by the [[TK83]] (it used a ULA similar chip, as the original ZX81) and by the [[TK85]] (a 16&nbsp;KB RAM version with a case similar to ZX-Spectrum), more robust and with a better design.

Microdigital later produced the [[TK90X]] and [[TK95]], which were clones of the [[ZX Spectrum]].

==Trivia==

'''TK82C''' is also a designation for a [[copier]] from [[Kyocera]].

==References==
{{Reflist}}

==External links==
* [http://www.old-computers.com/museum/computer.asp?c=912&st=1 Microdigital TK82] ([https://web.archive.org/web/20220803185825/https://www.old-computers.com/museum/computer.asp?c=912 archived version])

{{Sinclair computers and clones}}

{{DEFAULTSORT:Tk82c}}
[[Category:Microdigital Eletrônica]]
[[Category:Computer-related introductions in 1983]]
[[Category:Goods manufactured in Brazil]]
[[Category:Products introduced in 1982]]
[[Category:Z80]]
[[Category:Sinclair ZX81 clones]]


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