Hex values for VDP registers...
Posted: Mon Sep 22, 2014 5:51 pm
I have a general question about the usage of VDP registers.
Where do I find more information about the hex values? Are they in the Sega Manual? For example, move.w #$80xx,($C00004) for register 0... I'm curious about the 80 part of the hex value. I found in the YaVDP the hex values all the way up to register 15 which is #$8F. But that's the end of the document and there's more registers after that. Would register 16 for setting scroll size be #$90? Just need clarity here. I already understand how to setup all the bits for the instructions to the data + control ports, thanks to the vdp calculators I found.
Thanks again for the help. I have my first screen layout on Plane A loaded using a nametable, and it's skewed beyond the boundaries of the screen. I figured either I set the scroll size, or I do some code that resets the x coord back to 0 and y down to the next line once the drawing routine reaches the rightmost part of the visible display area. Either way, I would like to understand register 16 and up better.
Where do I find more information about the hex values? Are they in the Sega Manual? For example, move.w #$80xx,($C00004) for register 0... I'm curious about the 80 part of the hex value. I found in the YaVDP the hex values all the way up to register 15 which is #$8F. But that's the end of the document and there's more registers after that. Would register 16 for setting scroll size be #$90? Just need clarity here. I already understand how to setup all the bits for the instructions to the data + control ports, thanks to the vdp calculators I found.
Thanks again for the help. I have my first screen layout on Plane A loaded using a nametable, and it's skewed beyond the boundaries of the screen. I figured either I set the scroll size, or I do some code that resets the x coord back to 0 and y down to the next line once the drawing routine reaches the rightmost part of the visible display area. Either way, I would like to understand register 16 and up better.