Changes
/* Second schematic RAM+VGA */
Do "paper 2", "cls" on JavaCPC, the screen became RED, and then save a snapshoot, you can see that last part (from 0xC000 to 0xFFFF) had change from a lot of 0x00 into a lot of 0xFF
So last part of RAM is used for video (it's shown on Quasar [[http://quasar.cpcscene.com/doku.php]] and other legend websitewebsites...)
For making my VGA module, I take a look at unix "modeline" command that give us all timing for VGA signals, and it run :)