This utility was used to modify Mode 2 screens - probably could be used with Mode 0 and Mode 1 screens as well but I haven't tried them yet.
https://www.youtube.com/watch?v=6FL4Zjteiyg (https://www.youtube.com/watch?v=6FL4Zjteiyg)
Links:
http://www.cpcwiki.eu/index.php/VIDI_... (https://www.youtube.com/redirect?q=http%3A%2F%2Fwww.cpcwiki.eu%2Findex.php%2FVIDI_digitizer&redir_token=V1wxYiY4cGX0AACXoVhLkk1VOq58MTU3NDgzNTc4MkAxNTc0NzQ5Mzgy&v=6FL4Zjteiyg&event=video_description)
http://www.cpcwiki.eu/index.php/Video... (https://www.youtube.com/redirect?q=http%3A%2F%2Fwww.cpcwiki.eu%2Findex.php%2FVideo_modes&redir_token=V1wxYiY4cGX0AACXoVhLkk1VOq58MTU3NDgzNTc4MkAxNTc0NzQ5Mzgy&v=6FL4Zjteiyg&event=video_description)
Not emulated - original hardware and software.
Please note that the aspect ratio for this YouTube video is 16:9 but the CPC monitor
has an aspect ratio of 4:3 so you may wish to adjust your viewing device accordingly.