The original operating software of the CPC was a combination of a Basic interpreter (Locomotive BASIC) and the operating system itself. That was usual for many 8bit platforms during the late 70s and the 80s and even for 16bit systems like the Sinclair QL.
The operating system itself is stored inside one 16KB rom, which also includes the charset definition and the mathematic arithmetic routines. The last ones are not a part of the OS itself but of Basic. Regarding the general rules for an operating system the CPC OS has been designed in a way, that all its software is able to run completely hardware independant.
- Kernel (KL): RST and interrupt management
- Machine Pack (MC): applications and low level hardware tasks
- Screen Pack (SCR): low level screen routines
- Text Screen (TXT): text output, based on the Screen Pack
- Graphics Screen (GRA): graphic output, based on the Screen Pack
- Keyboard Manager (KM): keyboard routines
- Sound Manager (SOUND): sound routines
- Cassette Manager (CAS): mass storage routines, which are in general replaced by AMSDOS on the 664/6128
- Screen Editor (EDIT): multi line text editor