Sharp MZ 80K - 1979
Sharp obviously liked the MZ scheme for naming computers. The M represents the item is a microcomputer and the Z80 representing the processor. The K is a mystery since it was eventually replaced by the A,B and C ranges! This Sharp is immediately recognisable by the keyboard which is arranged in a grid format rather than as usual with each row of keys half a key width out of alignment with the one above. It also had a short space key surrounded by other keys. All the early Sharps were huge and heavy comprising the computer, cassette desk and monitor in a big metal case. The 80K is termed a "clean" computer. This means that the computer had only a small ROM chip and any language like BASIC had to be loaded from the cassette. This could be irritating as it took a while to load (though the cassettes were always incredibly reliable) but it meant that you could load different languages according to mood and requirement. I am aware of at least 5 different versions of BASIC being available.
These are still not difficult to find though they often appear broken. Some of the capacitors in the power supply degrade with age, eventually burning out and possibly taking with them a few other components. If you can spare a few pounds and are handy with a soldering iron then this is easily fixed and these computers are still very powerful today.