12-07-2011, 06:24 PM
boriel Wrote:Oh my...:!:
I've just read this post TODAYhock:
I would like to know a bit more about this engine.
I'm not sure what more detail I can give, although you can try out the software here:
<!-- m --><a class="postlink" href="http://www.worldofspectrum.org/infoseekid.cgi?id=0026639">http://www.worldofspectrum.org/infoseek ... id=0026639</a><!-- m -->
It's a software driven 144x144 window of rainbow processing (8x1 attributes) powered by LD / PUSH. The routine includes a tile engine so you don't have to worry about updating the LD / PUSHes yourself. It supports up to 256 tiles. Each tile is 16x16 pixels (and takes up 64 bytes). Tiles are drawn continuously, based on an 81 byte tile map. You update the map to update the tiles. The original version of the code draws only 3 tiles per interrupt (it's all IM2 driven). The next version draws 9 tiles per interrupt.
In theory the window can be relocated anywhere on the screen but moving it lower down would reduce the available t-states to do anything else in.
There's a good explanation of what's going on here:
<!-- m --><a class="postlink" href="http://simonowen.com/blog/2011/09/29/zxodus-engine/">http://simonowen.com/blog/2011/09/29/zxodus-engine/</a><!-- m -->
Cheers!
-chev