The story
Richard and Julian's first foray into the computer games business is documented on the official Llamasoft web site, with the Joneses and Jeff Minter forming a partnership in 1982. Although the Llamasoft account of the parties' short relationship and the events surrounding the dissolution of the partnership reflect Jeff Minter and his family's opinions, the key facts and dates do not seem to be in dispute. The Jones' and Minters' short-lived partnership ended in September 1982. History has shown that neither party's interest in the business suffered from the split, with Jeff retaining the Llamasoft name and the Joneses forming Interceptor. The company released several clones of arcade games but decided to focus on developing more original titles, as stricter copyright laws meant the clones could not be sold in the USA.
From Wikipedia’s article on Interceptor Micros, shared under CC BY-SA 4.0.3