SpritesMind.Net

Hey thanks, this is perfect.

I found Pascal's VDP calculator and I wanted to try out TmEE's as well but the link is dead. I just wanted to try it out, I like having dos stuff.

Although this forum probably isn't as lively as it once was. Everyone here has been really helpful and tolerant of my noob mistakes. I just wanted to thank you guys real quick. Now, more work to do.

That indeed was the problem, and you fixed it.


VDPRegisters:
dc.b 0x20 ; 0: Horiz. interrupt on, plus bit 2 (unknown, but docs say it needs to be on)
dc.b 0x74 ; 1: Vert. interrupt on, display on, DMA on, V28 mode (40 cells vertically), + bit 2
dc.b 0x30 ; 2: Pattern table for Scroll Plane A ...

Well after your suggestion I tried 0x0c81, 0x0c87, 0x0c06, and 0x0c00 in the main program code, and all values result in black screen. At least now, I know how to better manipulate the VDP. Thanks for pointing me in that direction.

EDIT: Putting that VDP control instruction before my palette code ...

Hi there. I'm working on an M68k music tracker for the Genesis. In preparation for doing the GUI I was testing loading palettes to the VDP. Although I'm not too sure I was able to successfully load a palette (which is surely my fault), I was able to successfully fill the screen with a color (any ...

powerofrecall wrote:...and maybe the interactive VDP docs at the bottom of that page.

THAT, is awesome.

Cool thanks for the info. Maybe I can learn 68k AND figure out how to do a hello world at the same time . I really want to get started messing with the genesis immediately. Then once I figure all that out I can start on the YMDJ tracker GUI and control pad input. Then I'll worry about the sound ...

Oooh more learning.


setcolor:
move.l #0xC0000000,%d1
move.l %d1,0xC00004 | setup CRAM write
move.w %d2,0xC00000 | write bg color


I want to make sure I understand this because it's interesting to me. From the Genesis manual if I understand correctly, 0xC00004 is the address for the control ...

Nice to know, that makes this project seem a lot less complicated, although I know it will still be complex. At least Algebra is painless.

I understand what you're saying. I've thought of ways I could use 68k to do something useful, beyond apparently just moving bytes around. Something like, read ...

Well I think you've given quite a comprehensive explanation as to why my attempt didn't quite work. That primer book is very useful and easy to understand. Thanks to all your help I can move on to the next step and continue to learn this fascinating language.

Now while I'm playing around with 68k ...

Ahhh so basically that code was basically a bit sloppily done (no offense to the original coder of course) by a coder who was relying on the assembler to do optimizations.

As for vtimer, I figured I'd have to declare that variable, I just wasn't sure how to go about it properly in asm (I attempted ...

Okay.
I got a couple of errors with that init code.

Line 55 move a6,usp
asm68k complained about data size, so I changed the move opcode to move.l

Line 154? addq.l #1,vtimer
asm68k complained about vtimer being undefined. I looked around to see if I could figure this one out, but couldn't and ...

I'm using no startup code. The code above is all I have. So basically I need a header and code to initialize the genesis before this code can even be used right? I was hoping I could just jump in and start learning and toying with 68k without having to do all that. I'm using asm68k.exe.

Although I ...

Regen might not like that because based on the genesis memory map, you'd be writing to ROM there. Genesis RAM starts at $FFFF0000 and lasts till $FFFFFFFF (64kbytes). Try that out and you can peep in Regen's RAM viewer to see it work.

Yeah I probably should've taken a closer look at the sega doc ...