Cambridge Microelectronics

16K RAM pack using CMOS 6116 static RAM chips for permanent data retention. Data can be stored almost indefinitely and loaded almost instantly with virtually zero chance of error. A long life (10 years) lithium battery supplies power in standby mode. In the active mode, power is taken from the ZX81. Used on its own,

Contains one or two 2K (6116) CMOS RAM chips. Memory is addressed into the ROM area from 8K-16K in the ZX-81 memory map. The address at which each chip appears can be adjusted to any 2K section within that area. Lithium battery in the unit provides a back-up power while the computer is switched off.

Store useful routines and commonly used information in EPROM. Accepts either 2716 or 2732 EPROMs to allow up to 8K of memory in 2K byte increments. Separate 2K and 4K decoding is link selectable. Mapped to the 8-16K area in the TS 1000 memory map.