One characteristic was common to the microcomputers of the late 1970s and early 1980s, they all tended to have BASIC included on a system ROM. Well there was one notable exception, the Jupiter Ace. It was the first home computer to be based on Forth instead of BASIC . The Ace was developed by British company Jupiter Cantab and released in 1982.
Apart from Forth the Ace was quite typical of the period having a Z80A CPU at it's heart and 1KB of RAM (my Mac has four million times as much memory), in terms of form factor it was not unlike the Sinclair ZX81 though a different colour of course and with rubber keys. It also had quite a different internal arrangement though not unlike the Spectrum in some ways (the designers were ex-Sinclair who had worked on the ZX81 and Spectrum).
Forth was chosen as it was considered ideal for a computer like the Ace being fast and compact and a structured language compared to the BASICs of the time. Unfortunately the Ace didn't catch on, the lack of BASIC ended up being a massive hinderance not a bonus. When you are swimming against the flow you need to be really really good and the Ace, despite some nice features, was not. Its graphics were low resolution black and white (64x48) and it lacked decent sound. Forth was also not as easy for beginners to learn compared to BASIC.
For the average home user it was not really that attractive though the inclusion of Forth and the ability to expand the Ace to 51K meant it had appeal to hobbyists. However there were not enough of them to make it a hit.
Around five thousand of the original Ace and eight hundred of the Ace 4000 with an improved case are reported to have been sold. The Ace was discontinued in 1984.
 Max Philips, Microcomputer Catalogue (Marshall Cavendish, 1983) p. 14