Carrying on from where Vic Computing left, Commodore User was launched in September 1983. Initially the magazine contained what was referred to as the serious side of computing, with programming tutorials, machine code features and business software reviews. The first issues were produced and written by a small team, consisting of editor Dennis Jarrett, a writer (future editor Bohdan Buciak) and editorial assistant Nicky Chapman. Features were written by a range of contributors. Rapidly the issue sizes grew from 64 to 96 pages.

Games coverage began to appear during 1984, consisting of a small section called Screen Scene. This became a permanent fixture throughout the magazines life.

By 1985 the Commodore 64 became more popular and the magazine began covering the newer machine more and more, leaving the Vic-20 in the dark. The amount of technical coverage also decreased as the games market took over. Gradually the circulation began to rise and CU produced more colour through the magazine. At the height of the C64's success, CU had a page count of 116.

In 1986 CU began to cover the new 16-bit computer; the Amiga. The magazine was at an all time high, covering all the Commodore platforms, from the C16, all the way up to the Amiga. Circulation figures were also showing an all-time high of over 70,000 for the 1988 period.

To establish that the magazine content was changing to cover the emerging Amiga, the magazine changed its title CU Commodore User Amiga-64, with the emphasis on the CU part. The Commodore User part was quickly dropped and the name remained CU Amiga-64. This period of the magazine was seen as a transitional time between transferring coverage from C64 to the Amiga.

Realising that the C64 market was in an undeniable decline in 1990, CU made the decision to concentrate fully on the Amiga, dropping C64 coverage and relaunched their redesigned magazine as CU Amiga.