Hey All,
If you are interested in using the Retro Virtual Machine (http://www.retrovirtualmachine.org/) Emulator for the Amstrad CPC range and would like to start Z80 coding, here is a video that explains how to do it. It also goes into how to encode pixel colours using Mode 1 and fast screen updating.
Z80 Coding with Retro Virtual Machine for the Amstrad CPC (https://youtu.be/CpssMjMlsWM)
Ha, would be great if somebody would do such a great video for FutureOS coding in Z80. Sadly I lack the equipment.