The Sinclair ZX Interface 2, introduced in 1983, established the original ROM cartridge standard for the ZX Spectrum. It allowed software to be loaded almost instantly from ROM cartridges, although the format was short-lived and only ten titles were commercially produced. Sinclair also produced a test cartridge for servicing and testing, but this was not a retail product.

Other ROM cartridge interfaces and systems subsequently appeared, offering different approaches to cartridge storage and access. This section includes systems sold primarily as ROM cartridge interfaces; where cartridge facilities were an additional feature of another type of expansion, the system is listed in the appropriate section.