Non-volatile RAM and Real Time Clock (RTC) for Amstrad CPC.
This card is primarily intended as a debugging tool for developers.
All Nova cards come with the 32KB chip. Source
Ports
The interface uses only one port (&FE82) to map the NVRAM in and out. It is possible to map it at any address multiple of &2000.
The NVRAM, when it is enabled, masks 8K of RAM or ROM and replaces it with its own contents. Four NVRAM pages of 8K are available.
In the fourth page, the last 8 bytes are not normal RAM, but can be used to read and write the time from the realtime clock.