From Sega Retro
The Othello Multivision (オセロマルチビジョン) is an SG-1000 clone manufactured by Tsukuda Original. It exists because Sega's original intention for the SC-3000 computer was to allow other manufacturers to produce compatible computers in the hope of having a worldwide standard. Unfortunately, possibly with the emergance of the MSX, this tactic failed, and very few SG-1000/SC-3000 compatible machines were produced. The Othello Multivision was one of those machines.
Similar to the SG-1000, there are two versions of the Othello Multivision, named the FG-1000 (released 1983) and FG-2000 (released 1984) respectively. As well as being able to run SG-1000 and SC-3000 cartridges, the Othello Multivision saw a number of games and software released with Othello Multivision branding. The system also came with the game Othello built-in.
One of the major problems with the Othello Multivision is that rather than rely on external game controllers, all the controls are built into the unit. It is compatible with several SG-1000 add-ons, however, including the SK-1100 which would enable the SC-3000's keyboard functions. FG-1000 models shipped with an overlay which would explain the functions of each key.
The FG-2000 model brought support for a second controller. This model can easily be identified by the fact it uses blue keys rather than red ones and the fact the built-in joystick has been replaced with a directional pad.