Search found 256 matches

by tomaitheous
Thu Jun 10, 2010 6:35 pm
Forum: Tools
Topic: BMP to MD file converter
Replies: 14
Views: 5682

Something somewhat relative to this topic; range compression. Perception of a color brightness is partially relative (like anything else). If you avoid using pure black and use 1,1,1/1,0,1/1,0,0/0,0,1 - you get an interesting effect (as long as the person/viewer doesn't see true black anywhere on sc...
by tomaitheous
Fri Jun 04, 2010 9:20 pm
Forum: Video Display Processor
Topic: VDP Status Register
Replies: 17
Views: 8041

You mentionned something about F flag : Vint occurrance You said that if the bit isn't cleared (by reading the status register) then the Vint stay asserted by the VDP and the 68000 will re-enter in V int routine infinitly. Are you sure of that behavior ? Is it possible that the 68k requires a state...
by tomaitheous
Sun May 09, 2010 5:29 am
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

I decided to use this thread to catalog games that use more than five scrolls in games. Over the next few days I will be adding the catalog of games I have already tested to the original post. Bimini Run - eight line scrolls to the horizon Waves animate to appear like scaling Only one layer represe...
by tomaitheous
Fri Apr 09, 2010 5:37 am
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

Thank you Mr. MacDonald. It took me twice as long to skim through SNES documentation as it did Genesis or TG16 docs because there is over twice as many documents, and because they are far more technical in nature. Overall, I haven't found any technical reason why the SNES library doesn't exemplify ...
by tomaitheous
Wed Apr 07, 2010 4:25 am
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

Anomie's Register Doc Version WIP (reg.txt) implies that Mode 2 is virtually identical to the way the Genesis VDP handles backgrounds. I am sure there are differences, but capability wise I cannot see why this mode couldn't be just as capable of 8 line scrolls as the VDP is. Tile offset mode? I wou...
by tomaitheous
Sat Apr 03, 2010 8:41 pm
Forum: Blabla
Topic: Games for porting to SMD
Replies: 21
Views: 9228

I'm told the source code for those isn't usable as source code (i.e. it would take an unacceptable amount of work to repair them for use with an assembler). Look at the SMB source for yourself, it's quite complete. It's not machine generated disassembly, it was done by hand - tracing through the ga...
by tomaitheous
Sat Apr 03, 2010 6:30 pm
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

HDMA aside, it seems like SNES developers chose to design their games around the SNES' "Mode" system for backgrounds. Based on the games, I'd say they typically stuck to Modes 1-4 if they weren't using Mode 7. At least, I can't think of any reason why they would want an overabundance of 4-color bac...
by tomaitheous
Fri Apr 02, 2010 2:37 am
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

I would also say that the MD with the faster CPU, has more time to update a huge table of scroll values. But with SNES's HDMA you don't have to do every single line, which can save time. Yup. And on the MD, if you enable row or line scroll table mode, you have to set *every* entry for *both* planes...
by tomaitheous
Thu Apr 01, 2010 6:34 am
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

Tom, are you actually trolling me? If you don't want to contribute to the topic, start your own please. Troll, sir? No, sir. What I stated and asked was very relative to what the topic at hand is discussing. I took hours of my time to explain near the very beginning of that "other" thread. I wasn't...
by tomaitheous
Thu Apr 01, 2010 2:07 am
Forum: Video Display Processor
Topic: Understanding the VDP's scrolling capabilities.
Replies: 61
Views: 25237

8-10 independently scrolling background layers, with some showing individual line scrolling at the same time, was only done in Genesis software. I'm trying to figure out whether there was some hardware related reason why this is true. The VDP supporting the effect locally provides just such a reaso...
by tomaitheous
Tue Mar 30, 2010 9:31 pm
Forum: Blabla
Topic: RealArcade Genesis emulation
Replies: 9
Views: 4979

Was there any reason to use this pay per game emulation over the standard emulation for Genesis at the time? I don't remember this app/site.
by tomaitheous
Wed Mar 24, 2010 4:52 am
Forum: Blabla
Topic: Games for porting to SMD
Replies: 21
Views: 9228

I can think of two perfect candidates: SMB1 and Metriod for NES. But are disassembled with commented and sorted source code (well, SMB1 anyway. Haven't looked at the Metriod source).
by tomaitheous
Sun Feb 21, 2010 10:26 pm
Forum: Video Display Processor
Topic: Color counts per screen
Replies: 137
Views: 40307

My premise is simple, if we are going to make subjective qualitative statements about the games, then we need to consider what conditions the target audience was viewing the games under. If you can't see the logic in that we genuinely have no further basis for a discussion on the matter. So subject...
by tomaitheous
Fri Feb 19, 2010 5:28 am
Forum: Video Display Processor
Topic: Color counts per screen
Replies: 137
Views: 40307

oops, I was wrong about CRAM size, didn't know 9-bits memory existed, thanks for clearing that up. Strange thing is the data format when writing from CPU, why would you need to write zeros between 3-bits pixels values, maybe it's 12-bits, not 9 ? From a developer stand point, that's easy. It's easi...
by tomaitheous
Thu Feb 18, 2010 12:38 pm
Forum: Video Display Processor
Topic: Color counts per screen
Replies: 137
Views: 40307

Something that never really came up, was that the original VDP (and on a few models after the first), that the VDP had serial output. A digital bus. 10bits IIRC because it has S/H status bits. Anyway, you can also easily detect sprite pixels from BG pixels on the bus - by checking the corresponding...