7800 Graphics Modes

Entry posted by Guest May 8, 2005

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Figured out what the problems were. The main one was my ROM->RAM copy routine needed to be reworked since it had to copy more than 128 bytes.Attached is a simple test program which displays all 6 graphics modes onscreen. Press player 1 button to enable kangaroo mode, press player 2 button for colorkill (may be combined). (CC2 7800_8K 78QUICK, should work on both NTSC and PAL)Okay, what are you looking at, eh? The screen is divided into 9 areas (3x3 grid):320A (pallete 0-3) 320C (palette 0,5,6,3) 320A (palette 4-7)320D (pallete 0-3) 320B (palette 0,5,6,3) 320D (palette 4-7)160A (pallete 0-3) 160B (palette 0,5,6,3) 160A (palette 4-7)And for each palette byte values 0-255 in a 16x16 grid (see the code for the palette values).What this shows is there is some kind of strangeness with modes 320D & 320B wrt Kangaroo mode. (Which is what was suspected.) I need to stare at the screen a while longer to try and figure out what is going on.

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