Changes
CRTC
,/* CRTC-II (aka Type 5) */
This chip was never used by Amstrad. However, some CPC enthusiasts have replaced the original CRTC chip in their CPC with this one.
With this chip, split-screen becomes easy: [https://thecheshirec.at/2024/05/20/des-splitscreens-en-basic-sur-crtc5/ Split-screen in BASIC]. And 3 new graphics modes (160x100160x100x16, 320x100320x100x4, 640x100640x100x2) are available: [https://thecheshirec.at/2024/11/10/trois-nouveaux-modes-video-grace-au-crtc-5/ New graphics modes in BASIC].
This is the cheapest way to upgrade the CPC's graphics capabilities, costing only 1.29€. [https://thecheshirec.at/2024/05/19/des-crtc5-a-129e/ Source]