TK90X
PAL-N, NTSC, 256 x 192, 15 colours | |
Graphics | CMOS IC |
---|---|
Sound | Single channel 1-bit DAC |
Backward compatibility | ZX Spectrum |
The TK90X was a Brazilian
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
Microdigital reverse engineered a
The TV modulator was tuned to
(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
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.
- 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.
- 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)