The Sega SG-1000, the Memotech MTX, the Tatung Einstein, and the ColecoVision all have many similarities with the MSX1 standard, but none are fully compatible with it. Porting games between those systems is somewhat easy. It was also very common to port games from the ZX Spectrum to the MSX, since both have the same CPU, the Spectrum 128 had the same soundchip, and the ZX Spectrum's graphic mode could be easily emulated on the MSX's screen-2 mode.