Bit Corporation Bit90
This page was last modified 17:40, 3 September 2022 by Mars2000you. Based on work by Gdx and Bodhi1969.



The Bit Corporation Bit90 is a computer which is ColecoVision compatible. It is available in two colors (white with black keys or silver with green keys).

The power supply is external. The expansion bus at the back can host RAM packs (memory expansions) or interfaces for different peripherals: disk drive, printer (Centronics parallel), RS-232C.

The keyboard has a BASIC key, allowing to type directly a BASIC instruction by pressing just a dedicated key.

This computer doesn't support software for Coleco Adam. An adapter for Atari VCS/2600 cartridge was sold separately, too.

Brand Bit Corporation
Model Bit90
Year 1984
Region Argentina, Taiwan and maybe some other countries
Launch price Germany: DM 598 - The Netherlands: ƒ699 + 16kB RAM pack: ƒ229
Media ColecoVision cartridges
Video Texas Instruments TMS9918A/TMS9929A
Audio Texas Instruments SN76489AN
Keyboard layout QWERTY
Extras Reset button, BASIC key (the keyboard itself is an extra compared to the ColecoVision)


Bit Corporation Bit90
Bit90 PCB
Bit90 box
Bit90 left side
Bit90 back
Bit90 right side
Bit90 power supply
Bit90 pamphlet
Bit90 pamphlet back


The CPU is a Zilog Z80 (Z8400A).

Bit90's pamphlet says it has 18kB RAM but in fact there are 2kB RAM (TMM2016AP) + 16kB VRAM (AM9016 x 8). This RAM can't be used for programming, you need at least a 16kB RAM pack inserted in the expansion bus.

The ROM size is 24kB, it contains the BIOS and a Basic interpreter.

The data recorder rate is 2400 baud. The joysticks ports are same as ColecoVision. The connector is same as MSX but not compatible. Do not insert a ColecoVision game controller into an MSX.