The Silent Demo

It has been a long time ago when I did write this demo. As far as I know this demo was the first ever to have a color rainbow based on raster-interrupts and some other neat effects. The large scroller for example is done on one of the text screens. The effect is performed by continuously updating the font table.

It was quite difficult to get the vertical and horizontal interrupts working. Especially since all available documentation at that time did not describe the registers of the VPU. Or if they did, it was wrong. But I found the correct settings. And I had to really count the length of the assembly instruction in clockticks, because MSX is just so slow. Especially the I/O ports to program the VPU are expensive in CPU ticks. It is easy to make a split screen, it is something completely different to program a new color value in one of the registers at *every* rasterline!

The demo would be nicer with music, but I simply could not find the needed CPU time to handle the music.

Nice to see that are all that time the demo is still available!

- Shadow Knight (SHK)

I get a demo with red, white and blue color bars (and some wacky sprite on top of the screen, I think). More parts too.