The AX-990 was an MSX1 computer released around 1992 for the Arabic market under the Sakhr brand by the Al-Alamiah company. It was a dual-mode machine: both an MSX1 home computer and a Sega Mega Drive games console. The two modes could be switched between using a push button on the rear of the case.
The two halves of the machine were not capable of interacting with each other (as in the Sega Teradrive). The power supply, composite video encoder, and joypad/joystick ports were shared; while the MSX and Mega Drive circuits were switched on and off as required.
From above the AX-990 looks like a standard MSX machine. The cartidge slot on the right is for MSX cartridges; the one on the left is for Sega Mega Drive games.
Note that there are two 'reset' keys on the top row: one to reset the MSX, and one to reset the Sega half of the machine.
With the top cover removed and the keyboard lifted up we can see that this really is two machines in one case.
The PCB on the right holds the MSX CPU, ROMS, VDP, and sound chips. It also has the printer port, RGB video port, and the two joystick ports. The PCB on the left contains the Sega Mega Drive and shared power supply and video mixer circuitry.
With the machine facing you the back panel holds, from left to right:
- Mains power in.
- Input voltage switch (120V/240V).
- RF video output (tunable with set screw exposed on PCB rear side).
- Composite video out.
- Mono audio out.
- MSX/Sega toggle switch.
- MSX printer port.
Note the large transformer on the left, which provides most of the machine's weight. If you have the machine plugged in do beware that mains voltages are exposed with the case removed. Since the mains plug is unpolarised potentially anything left of the RF modulator can be live.
More information about the AX-990 (including the supplied MSX firmware) is available on the msx.org wiki.