BSC Megademo - 4 bitplanes part

A world record? Or just another random old CPC thingie? Or something else?
This should have been part of my other video of BSC Megademo, but the emulator I used for recording failed to show this part, so here it is for all of you who have eagerly sitting in anticipation :)

[@mageamstrad]

That tune :

[@josyfkristopher4320]

Correct me if I am wrong, but is this running in 640 by 200 mode? Seems very high detail so I am impressed that you got so many colours visible on what would normally be a 1bit colour depth (former C64 coder here with honest respect for CPCs).

[@fygarOnTheRun]

The actual mode used here is Mode 1 which has a resolution of 320x200 pixels and can display 4 colours (out of 27) at once. This here is a mode 1 screen reduced in width - 256 pixels I guess. All the additional colours you see are due to rasters. A common effect on most 8-bit machines :)

[@josyfkristopher4320]

@@fygarOnTheRun Ah, yes - I forget that the Motorola 6845 and the custom ASIC were rather flexible. I recall ZZKJ releasing a hack that allowed 160x200 with 8 colours to reduce RAM usage (and this CPU time)? Compared to the C64, the CPC certainly had a more vibrant palette (my principle point of envy).
The C64 used a good effect called AFLI where you were limited to two colours every 8 pixel wide cell but you could select different colour RAM every scanline to keep changing the palette. It chewed up both 17KB of RAM and nearly 80% of the raster time on PAL systems but made for cool high resolution full palette displays.

[@fygarOnTheRun]

I still have to learn about the gfx tricks you can do on the C64, because some of the FLI and similar modes look just awesome.