Graphics Mode 4 video demo source

Hello,
I'm looking for some source code for a z80 which utilizes the various graphics modes (particularly vdp mode 4 and sprites) on a vdp 9938 or 9958 chip. The code is not MSX specific as it is a homebrew system which I'm working on.
Also I have an emulator of sorts running so far but it only supports vdp text1 and vdp mode4, still a work in progress which has taken me a while to get through.

Any advice would be really helpful.

Regards