TK90X: Difference between revisions

TK90X
Manufacturer	Microdigital Eletrônica
Type	Home computer
Release date	1985; 40 years ago
Operating system	Sinclair BASIC
CPU	Zilog Z80A @ 3.58 MHz
Memory	16KB or 48KB RAM
Display	TV RF output (VHF channel 3), PAL-M, PAL-N, NTSC, 256 x 192, 15 colours
Graphics	CMOS IC
Sound	Single channel 1-bit DAC
Backward; compatibility	ZX Spectrum

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The TK90X was a Brazilian ZX Spectrum clone made in 1985 by Microdigital Electrônica, a company from São Paulo, that had previously manufactured ZX80 (TK80, TK82) and ZX81 clones (TK82C, TK83 and TK85).^[1]^[2]^[3]

Reported TK90X sales in October 1986 were 2500 machines per month.^[4]

Technical details

The case was a little taller than the original Spectrum and the keyboard placement was equal to the original keyboard, except for some additional Sinclar BASIC commands that did not exist in the Spectrums (UDG for user defined characters in the place of the £ sign - including specific Portuguese and Spanish characters such as ç and ñ, as well as accented vowels - and the Trace function).^[5]

There were two versions of the machine, with 16 and 48 KB of RAM.^[6] They contained the same Z80A processor running at 3.58 MHz,^[7] ROM chip and RAM chips (dynamic RAMs 4116 and 4416).

Microdigital reverse engineered a CMOS integrated circuit (IC) with similar functionality to the original bipolar IC ULA from Sinclair/Ferranti. Most software written for the Spectrum ran on the TK90X, with some minor incompatibilities.

The TV modulator was tuned to VHF channel 3, with the TV standard being hardware selectable to PAL-M (60 Hz) as used in Brazil, PAL-N (50 Hz) as used in Uruguay,^[8] Argentina^[9] and Paraguay and NTSC (60 Hz) as used in USA and many other countries.

An improvement over the original ZX Spectrum was the sound output via modulated RF direct to the TV set instead of the internal beeper.

Peripherals

Three peripherals were released by Microdigital: a joystick, a light pen interface and a parallel printer interface.

A Beta Disc Interface was available by third party companies, called 'C.A.S. disk drive interface' (a near-clone from the original Beta Disc interface), 'C.B.I. disk drive interface' (with an included printer interface) and 'IDS91' (with an included printer interface made by Synchron) or 'IDS2001ne' (also with an included printer interface made by Synchron, but exclusively compatible with the TK90X and TK95).

TK95

The TK90X was replaced by the TK95,^[10] which had a different keyboard and case (identical to the Commodore Plus4), while the circuit board and schematics remained unchanged (the motherboard was marked as TK90X). It also used the same ULA as the TK90X, with only digital logic ports and the analogue part outside the ULA chip.

This machine had a few ROM differences that made it more compatible with the original ZX Spectrum (e.g., the game Mikie runs only on the TK95, not on the TK90X). Some users created a switch the enabled choosing between the original TK90X, TK95 or ZX Spectrum ROM internally, in order to be able to run all of the Spectrum's software.

Export model

During the 1980s Brazilians were not allowed to import computers and therefore the TK90X became the first affordable color computer in the market.^[11] It was successful in other Latin American countries, such as Uruguay and Argentina, as an export model using a different circuit board and schematics, and the same Ferranti ULA as the ZX Spectrum.

Because of its affordability in Latin America, many commercial software programs were developed locally for small business use and millions of users had their first computer experience with the TK90.

There's an active user base of enthusiasts of this computer, with dedicated websites discussing software preservation, peripherals and homebrew development and modifications.^[12]^[13]

References

^ "TK-90X Microdigital". www.old-computers.com. Retrieved 2023-01-19.
^ Penix-Tadsen, Phillip (2019-05-20). Video Games and the Global South. Lulu Press, Inc. ISBN 978-0-359-64141-3.
^ Manchete (in Brazilian Portuguese). Block Editores. 1985.
^ "TK 95 chega ao mercado" (PDF). Micro Sistemas. November 1986. p. 16.
^ "Comandos Exclusivos de la TK 90X". CompuClasico - Antigüedades Digitales. 2019-03-27. Archived from the original on 2019-03-27. Retrieved 2023-02-21.
^ Woods, Tim (September 1987). "Brazil's TK 90X". Time Design. Vol. 3, no. 6. p. 2.
^ "TK-90X Microdigital Eletronica Ltda (Brazil)". 1000 BiT. Retrieved 2023-01-19.
^ Abbate, Janet; Dick, Stephanie (2022-08-30). Abstractions and Embodiments: New Histories of Computing and Society. JHU Press. p. 211. ISBN 978-1-4214-4437-6.
^ Visão (in Brazilian Portuguese). 1986.
^ "TK 95 chega ao mercado" (PDF). Micro Sistemas. November 1986. p. 16.
^ Martins, Marcelo (2011). "Tudo Sobre: TK90X". Clube do TK90X. Retrieved 2023-01-19.
^ "Clube do TK90X". Clube do TK90X. Retrieved 2023-01-19.
^ "Implementação de uma saída A/V no TK90X/TK95". Luccas Eletrônica. Retrieved 2023-01-19.

External links

TK90X/95 Mailing list - Mailing list about TK90X/95/Spectrum (English Speakers are Welcome)
ZEsarUX - ZX Second-Emulator And Released for UniX (GPL)

This computing article is a stub. You can help Wikipedia by expanding it.

This computer hardware article is a stub. You can help Wikipedia by expanding it.

[1] "TK-90X Microdigital". www.old-computers.com. Retrieved 2023-01-19.

[2] Penix-Tadsen, Phillip (2019-05-20). Video Games and the Global South. Lulu Press, Inc. ISBN 978-0-359-64141-3.

[3] Manchete (in Brazilian Portuguese). Block Editores. 1985.

[4] "TK 95 chega ao mercado" (PDF). Micro Sistemas. November 1986. p. 16.

[5] "Comandos Exclusivos de la TK 90X". CompuClasico - Antigüedades Digitales. 2019-03-27. Archived from the original on 2019-03-27. Retrieved 2023-02-21.

[6] Woods, Tim (September 1987). "Brazil's TK 90X". Time Design. Vol. 3, no. 6. p. 2.

[7] "TK-90X Microdigital Eletronica Ltda (Brazil)". 1000 BiT. Retrieved 2023-01-19.

[8] Abbate, Janet; Dick, Stephanie (2022-08-30). Abstractions and Embodiments: New Histories of Computing and Society. JHU Press. p. 211. ISBN 978-1-4214-4437-6.

[9] Visão (in Brazilian Portuguese). 1986.

[10] "TK 95 chega ao mercado" (PDF). Micro Sistemas. November 1986. p. 16.

[11] Martins, Marcelo (2011). "Tudo Sobre: TK90X". Clube do TK90X. Retrieved 2023-01-19.

[12] "Clube do TK90X". Clube do TK90X. Retrieved 2023-01-19.

[13] "Implementação de uma saída A/V no TK90X/TK95". Luccas Eletrônica. Retrieved 2023-01-19.

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@@ Line 1: / Line 1: @@
+{{Short description|Brazilian ZX Spectrum clone made in 1985 by Microdigital Electrônica}}
-{{Unreferenced|date=December 2009}}
+{{Infobox computer
-{{copy edit|date=December 2011}}
-[[Image:TK90X.jpg|thumb|TK 90X - Brazilian ZX Spectrum clone|right|256px]]
+| Photo = [[Image:TK90X.jpg|300px|TK90X — Brazilian ZX Spectrum clone]]
+| Type = [[Home computer]]
-The '''TK 90X''' was the first [[Brazil]]ian [[ZX Spectrum]] clone made in 1985 by [[Microdigital Eletronica]], a company located at [[São Paulo]], Brazil, that manufactured some [[Sinclair ZX81|ZX81]] clones before ([[TK 82C]], TK 83 and [[TK 85]]) and a [[Sinclair ZX80|ZX80]] clones (TK 80, TK 82).
+| Released = {{Start date and age|1985}}
+| Discontinued =
+| Processor = [[Zilog Z80]]A
+| Memory = 16KB or 48KB RAM
+| OS = [[Sinclair BASIC]]
+| unitssold =
+| compatibility = [[ZX Spectrum]]
+| graphics = CMOS IC
+| display = TV RF output (VHF channel 3), [[PAL-M]], [[PAL-N]], [[NTSC]], 256 x 192, 15 colours
+| sound = Single channel 1-bit DAC
+| manufacturer = Microdigital Eletrônica
+| CPUspeed = 3.58 MHz
+}}
+The '''TK90X''' was a Brazilian [[ZX Spectrum]] clone made in 1985 by [[Microdigital Eletronica|Microdigital Electrônica]], a company from [[São Paulo]], that had previously manufactured [[Sinclair ZX80|ZX80]] ([[TK80]], TK82) and [[Sinclair ZX81|ZX81]] clones ([[TK82C]], TK83 and [[TK85]]).<ref>{{Cite web |title=TK-90X Microdigital |url=https://www.old-computers.com/museum/computer.asp?st=1&c=945 |access-date=2023-01-19 |website=www.old-computers.com}}</ref><ref>{{Cite book |last=Penix-Tadsen |first=Phillip |url=https://books.google.com/books?id=DNOaDwAAQBAJ&dq=TK90X&pg=PT26 |title=Video Games and the Global South |date=2019-05-20 |publisher=Lulu Press, Inc |isbn=978-0-359-64141-3 |language=en}}</ref><ref>{{Cite book |url=https://books.google.com/books?id=86IwAAAAYAAJ&q=%22TK+90X%22 |title=Manchete |date=1985 |publisher=Block Editores |language=pt-BR}}</ref>
+Reported TK90X sales in October 1986 were 2500 machines per month.<ref>{{Cite news |date=November 1986 |title=TK 95 chega ao mercado |pages=16 |work=Micro Sistemas |url=https://datassette.s3.us-west-004.backblazeb2.com/revistas/micro_sistemas_062.pdf}}</ref>
-The case was almost the same of the original Spectrum (just a little higher), and the keyboard placement was equal to the original keyboard, except for some additional commands that did not exist in the Spectrums (for characters defined by the user — [[User-defined graphic|UDG]] — in the place of the 'Pound' symbol, and the 'Trace' function in Basic), and included specific Portuguese and Spanish characters such as ç and ñ, as well as accented vowels.
+==Technical details==
-There were two versions: 16&nbsp;[[kilobyte|Kb]] and 48&nbsp;Kb of RAM. Inside, the same processor: [[Zilog Z80|Z80A]] running at 3.58&nbsp;MHz, a [[Read-only memory|ROM]] chip, some [[RAM]] chips (old dynamic RAMs 4116 and 4416). Microdigital did some reverse engineering to develop a [[CMOS]] integrated circuit (IC) with similar functionality to the original [[Bipolar]]{{disambiguation needed|date=December 2011}} IC [[Uncommitted Logic Array|ULA]] from Sinclair/Ferranti. The modulator was tuned to VHF channel 3 and the TV system was hardware selectable to [[PAL-M]] (60&nbsp;Hz) as used in Brazil, [[PAL-N]] (50&nbsp;Hz) as used in Uruguay, Argentina and Paraguay and [[NTSC]] (60&nbsp;Hz) as used in USA and many other countries, versatility of features the ZX Spectrum never had ** (Was discover an original ZX Spectrum with NTSC video output in Chile, The ULA is a model 6C011E-3 which generates a NTSC frame size and rate)
+[[File:TK90X DISPLAY.JPG|thumb|TK90X boot screen]]
+The case was a little taller than the original Spectrum and the keyboard placement was equal to the original keyboard, except for some additional [[Sinclair BASIC|Sinclar BASIC]] commands that did not exist in the Spectrums (<code>UDG</code> for user defined characters in the place of the [[Pound sign|£]] sign - including specific Portuguese and Spanish characters such as {{Key press|ç}} and {{Key press|ñ}}, as well as [[Diacritic|accented]] vowels -  and the <code>Trace</code> function).<ref>{{Cite web |date=2019-03-27 |title=Comandos Exclusivos de la TK 90X |url=http://www.compuclasico.com/articulos.php?Enlace=tk90x/nota_tk90x |access-date=2023-02-21 |website=CompuClasico - Antigüedades Digitales|archive-url=https://web.archive.org/web/20190327180445/http://www.compuclasico.com/articulos.php?Enlace=tk90x/nota_tk90x |archive-date=2019-03-27 }}</ref>
+There were two versions of the machine, with 16 and 48&nbsp;[[kilobyte|KB]] of RAM.<ref>{{Cite news |last=Woods |first=Tim |date=September 1987 |title=Brazil's TK 90X |volume=3 |pages=2 |work=Time Design |issue=6 |url=https://archive.org/details/TimeDesigns/Time%20Designs%20v3%20n6/page/n3/mode/2up}}</ref> They contained the same [[Zilog Z80|Z80A]] processor running at 3.58&nbsp;MHz,<ref>{{Cite web |title=TK-90X Microdigital Eletronica Ltda (Brazil) |url=https://www.1000bit.it/scheda.asp?id=1396 |access-date=2023-01-19 |website=1000 BiT}}</ref> [[Read-only memory|ROM]] chip and [[RAM]] chips (dynamic RAMs 4116 and 4416).
-Another improvement over the original ZX Spectrum was the sound output via modulated RF direct to the TV set instead of the beeper.
+Microdigital reverse engineered a [[CMOS]] integrated circuit (IC) with similar functionality to the original [[Bipolar Junction Transistor|bipolar]] IC [[Uncommitted Logic Array|ULA]] from Sinclair/[[Ferranti]]. Most software written for the Spectrum ran on the TK90X, with some minor incompatibilities.
-Most of the software written for the Spectrum could be run on the TK 90X, but some minor incompatibilities occurred. Only three peripherals were released by Microdigital &mdash; a Joystick, a light pen interface and a parallel printer interface.
-But a Beta disc(48) interface was make by many third party companies called 'C.A.S. disk drive interface' (almost an exact clone from the original Beta disc interface), 'C.B.I. disk drive interface' (with a printer interface included) and 'IDS91' (with a printer interface included made by Synchron) or 'IDS2001ne' (these exclusively compatible only with the TK90X or TK95{no ZX Spectrum use possible},also from Synchron) (and also with a printer interface included) .
+The TV modulator was tuned to [[VHF]] channel 3, with the TV standard being hardware selectable to [[PAL-M]] (60&nbsp;Hz) as used in Brazil, [[PAL-N]] (50&nbsp;Hz) as used in Uruguay,<ref>{{Cite book |last1=Abbate |first1=Janet |url=https://books.google.com/books?id=s515EAAAQBAJ&dq=TK90X&pg=PA211 |title=Abstractions and Embodiments: New Histories of Computing and Society |last2=Dick |first2=Stephanie |date=2022-08-30 |publisher=JHU Press |isbn=978-1-4214-4437-6 |pages=211 |language=en}}</ref> Argentina<ref>{{Cite book |url=https://books.google.com/books?id=6IIYAQAAIAAJ&q=%22TK+90X%22 |title=Visão |date=1986 |language=pt-BR}}</ref> and Paraguay and [[NTSC]] (60&nbsp;Hz) as used in USA and many other countries.
-The TK 90X was replaced by the [[TK 95]], which had a different keyboard ( professional) and case (identical to Commodore Plus4), not in the rubber format, and exactly the same circuit board and schematics (even marked as TK90X on board, just a few difference in the ROM that made the TK95 more compatible with the original ZX Spectrum). But the same ULA chip, that have only digital logic ports with all the analogic part outside the ULA chip, exactly the same from TK90X. It have been reported that the TK95 had been providing more compatibility with the original ZX Spectrum (i.e. the game Mikie runs only on TK 95, not on TK 90X), but that was reported as a little change in the circuit board (the D1 diode has been disconnected, that made an improvement in ZX Spectrum compatibility) and the changes in the ROM from the TK95. Curiously, some games (fewer) became incompatible due to this modification. TK90X users in Brazil used to make a selectable switch to choose the original TK90X (or TK95) ROM or the ZX Spectrum ROM internally, so they could use almost all ZX Spectrum software.
+An improvement over the original ZX Spectrum was the sound output via modulated RF direct to the TV set instead of the internal [[Piezoelectric speaker|beeper]].
-During that period Brazilians were not allowed to import computers, and therefore the TK 90X became the first affordable color computer of Brazilians and was a big success. Similar status, because it was designed for Portuguese and Spanish language users, was achieved in other Latin America countries, as it was very successfully exported to Uruguay through its local distributor, [[Ingeniería de Sistemas]] (but the TK90X exported to these countries were a complete different circuit board and schematics, it also uses an original Ferrati ULA form ZX Spectrum, only externally was identical), and also to Argentina, Chile and Ecuador, where it competed with the Sinclair ZX Spectrum.
+=== Peripherals ===
-Because of its affordability, many commercial software programs were locally developed for the first time for use of small businesses in Latin America to run on the TK 90X, and millions of users had their first computer experience with it.
+Three [[Peripheral|peripherals]] were released by Microdigital: a [[joystick]], a [[light pen]] interface and a [[Parallel port|parallel printer]] interface.
+A [[Beta Disk Interface|Beta Disc Interface]] was available by third party companies, called ''<nowiki/>'C.A.S. disk drive interface'<nowiki/>'' (a near-clone from the original Beta Disc interface), ''<nowiki/>'C.B.I. disk drive interface'<nowiki/>'' (with an included printer interface) and ''<nowiki/>'IDS91'<nowiki/>'' (with an included printer interface made by Synchron) or ''<nowiki/>'IDS2001ne''' (also with an included printer interface made by Synchron, but exclusively compatible with the TK90X and TK95).
-== References ==
-<references/>
-* [http://www.tk90x.com.br www.tk90x.com.br]
+==TK95==
-== External Links ==
+{{Main|TK95}}
+The TK90X was replaced by the [[TK95]],<ref>{{Cite news |date=November 1986 |title=TK 95 chega ao mercado |pages=16 |work=Micro Sistemas |url=https://datassette.s3.us-west-004.backblazeb2.com/revistas/micro_sistemas_062.pdf}}</ref> which had a different keyboard and case (identical to the [[Commodore Plus4]]), while the circuit board and schematics remained unchanged (the motherboard was marked as TK90X). It also used the same ULA as the TK90X, with only digital logic ports and the analogue part outside the ULA chip.
+This machine had a few ROM differences that made it more compatible with the original ZX Spectrum (e.g., the game [[Mikie]] runs only on the TK95, not on the TK90X).  Some users created a switch the enabled choosing between the original TK90X, TK95 or ZX Spectrum ROM internally, in order to be able to run all of the Spectrum's software.
-* [http://br.groups.yahoo.com/group/TK90X TK90X/95 Mailing list] - Mailing list about TK90X/95/Spectrum (English Speakers are Welcome)
+==Export model==
+During the 1980s Brazilians were not allowed to import computers and therefore the TK90X became the first affordable color computer in the market.<ref>{{Cite web |last=Martins |first=Marcelo |date=2011 |title=Tudo Sobre: TK90X |url=http://www.tk90x.com.br/TK90X.html |access-date=2023-01-19 |website=Clube do TK90X}}</ref> It was successful in other Latin American countries, such as Uruguay and Argentina, as an export model using a different circuit board and schematics, and the same Ferranti ULA as the ZX Spectrum.
+Because of its affordability in Latin America, many commercial software programs were developed locally for small business use and millions of users had their first computer experience with the TK90.
+There's an active user base of enthusiasts of this computer, with dedicated websites discussing software preservation, peripherals and [[Homebrew (video games)|homebrew]] development and modifications.<ref>{{Cite web |title=Clube do TK90X |url=http://www.tk90x.com.br/ |access-date=2023-01-19 |website=Clube do TK90X}}</ref><ref>{{Cite web |title=Implementação de uma saída A/V no TK90X/TK95 |url=http://www.luccas.com.br/index.php/8-bits/artigos/17-implementacao-da-saida-a-v-no-tk90x-tk95 |access-date=2023-01-19 |website=Luccas Eletrônica}}</ref>
+== References ==
+<references/>
+== External links ==
+* [https://archive.today/20130105142344/http://br.groups.yahoo.com/group/TK90X TK90X/95 Mailing list] - Mailing list about TK90X/95/Spectrum (English Speakers are Welcome)
+* [http://sourceforge.net/projects/zesarux/ ZEsarUX - ZX Second-Emulator And Released for UniX] (GPL)
 {{Sinclair computers and clones}}
-{{DEFAULTSORT:Tk 90x}}
+{{DEFAULTSORT:Tk90x}}
+[[Category:Microdigital Eletrônica]]
+[[Category:Computer-related introductions in 1985]]
 [[Category:ZX Spectrum clones]]
+[[Category:Goods manufactured in Brazil]]
+{{computer-stub}}
-[[cs:Microdigital TK 90X]]
+{{Compu-hardware-stub}}
-[[es:TK 90X]]
-[[it:Microdigital TK90 X]]
-[[pt:TK-90X]]
-[[sr:Microdigital TK-90X]]

v t e Sinclair computers, derivatives, and clones
Sinclair Research / Science of Cambridge	MK14 ZX80 ZX81 ZX Spectrum (ZX Spectrum+, ZX Spectrum 128) QL
Amstrad	ZX Spectrum +2 ZX Spectrum +3
Licenced systems	ZX Spectrum Vega ZX Spectrum Vega+
Timex Corporation	T/S 1000 T/S 1500 T/S 2068 (TC 2068) TC 2048 TC 3256
Cambridge Computer	Z88
Lists of clones	ZX80/81 clones ZX Spectrum clones QL clones
Compatible or related systems	ZX80 based: MicroAce, TK80, TK82, NE-Z80 ZX81 based: Apply 300, AS-1000, Lambda 8300, CP-200, CZ 1000, CZ 1500, CZ 1000 plus, CZ 1500 plus, NE-Z8000, Ringo R-470, TK82C, TK83, TK85 ZX Spectrum based: ATM, Pentagon, CZ 2000, CZ Spectrum, CZ Spectrum plus, Didaktik, Dubna 48K, Hobbit,Scorpion ZS-256, Sprinter, Kay 1024, Komputer 2086, TK90X, TK95, Robik, ZX Spectrum Next QL based: CST Thor, One Per Desk, Q40/Q60 Other: SAM Coupé, Jupiter Ace
Sinclair Research peripherals	ZX Printer ZX Interface 1 ZX Interface 2 ZX Microdrive
Timex peripherals	TS2040 Printer TS2050 Modem FDD Disk Drive FDD3000 Disk Drive
Other peripherals	Beta Disk Interface DISCiPLE MB02 Rotronics Wafadrive Multiface Kempston Currah SpecDrum RAM Music Machine Stack Light Rifle Magnum Light Phaser
People	Clive Sinclair John Pemberton Rick Dickinson Richard Altwasser Steve Vickers