When Andrew Beer and I came up with this idea the intention was for people to build their own and many people have but once in a while someone comes up with something so amazing it really needs to be shared.
JamHamster came up with the idea of fitting a TZXDuino in a cassette. Originally it was powered by USB and had a 3.5mm Ear socket but it looked amazing.
Then he added a battery so that it was self powered.
Then he added a head from a CD to cassette adapter.
Then he added a switch under that head so that when you press play on the Cassette Recorder it plays the file you've selected.
And the TZXCassette was born
Because he is a great guy he's also uploaded the instructions on how to build one to Github and you can download the instructions and build your own.
Now at the moment there is no REM control it may not work as well with a CPC 464 as it does with with a Spectrum +2 but it is a stunning piece of electrical engineering and a work of art in my opinion.