To use the CP/M operating system on an Amstrad notepad NC200, you needed before ZCN by Russell Marks with a SRAM card.

But now it is also possible to use a rewrite of CP/M without any original Digital Research's code by starting from a disk with CP/Mish by David Given (see a youtube video).

All CP/MIsh sources are on Github for Linux.

The available memory is 60 Kb by using all the memory available (128 Kb) but please check the NC200 readme for more informations especially the warnings about files in RAM (lost after notepad is off), the disk cache (chance disk only at CP/M prompt, and switch off the notepad only at prompt or you may loose write disk accesses).