As many of you probably know I am mainly an Amstrad, Amiga and C64 kinda guy, although I have played many ZX Spectrum games and have played on the hardware many years ago, I don't in fact have a ZX Spectrum in my ownership. But what I do know, is that many retro computers including consoles don't have HDMI out unless you use a RF or SCART to HDMI converter. Problem with that is, they are usually not very good or the ones that are, are hugely expensive. But it is a time to rejoice HDMI users, as a new hardware device has been teased for the ZX Spectrum, the ' ZX-HD ' by Imre Jakli and Ben Versteeg.
Currently not much is known about the ZX-HD as it was only just teased today with very little info apart from coming soon. But it does look as if this could be the first time you'll be able to buy a straight ZX addon that attaches to the ZX Spectrum and outputs via HDMI. However one person did ask "Ula+? HDMI?" and the answer was YES and also " Probably a throughput pcb with HDMI output connector on left or right side ". So if a DivMMC outputting to pure HD gets you excited, you really should be keeping an eye on further developments.
Links : 1) Source