As I wrote in previous articles, one of the signs that helps to recognize hidden MSX devices are visual: MSX peripherals (joysticks, trackballs, keyboards, tablets, etc) or connectors that we relates to MSX (50-pin slots, keyboard, cassette, etc).
Those physical evidences plus those that we got by documental research, makes we try and buy a different device, with the hope that we will discover another piece of MSX history.
Most times that doesn't works. That's why I created the "Not MSX" category in this blog. So I can show these failed attempts and prevents other people to lose their money with the same mistakes.
Of course I will not write here about all "Not MSX" that are in the world, but about stuff that looks to be a hidden MSX, some even uses MSX custom ICs, and are not.