Search found 687 matches

by Sik
Mon Jul 16, 2018 8:45 pm
Forum: Cartridge
Topic: Size limits
Replies: 11
Views: 144

Re: Size limits

It's possible that particular mapper only had enough pins to map 32MB. And yeah, if I recall correctly there's work to make one that can address up to 128MB (we should call it the GIGA POWER cartridge since it's 1 gigabit :v). And technically nothing prevents you from using the remaining 8 bits from...
by Sik
Mon Jul 16, 2018 12:04 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 175
Views: 9756

Re: Tänzer, a "ninja" game (Dev Diary thread)

mix256 wrote:
Mon Jul 16, 2018 6:51 am
Slacking in updates, mostly because I'm hard at work on the game. Which is good, I guess.
You can pick a specific period (e.g. every one or two weeks) to do updates if you see there's enough regular progress to fill it in (・・ )
by Sik
Mon Jul 16, 2018 5:43 am
Forum: Cartridge
Topic: Size limits
Replies: 11
Views: 144

Re: Size limits

For the record, I'm not sure where the 32MB limit comes from (as we don't have any actual official docs from the mapper - what we know is from reverse engineering I think?). But yeah, you can use the mapper to go over 8MB easily if you have a cartridge that actually provides that much memory. In the...
by Sik
Mon Jul 09, 2018 7:35 am
Forum: Megadrive/Genesis
Topic: 68000 programming optimization tips? (for speed)
Replies: 21
Views: 2244

Re: 68000 programming optimization tips? (for speed)

The Scc instructions only come in byte size so if I want a word or long result I actually need to use AND if I want 1 instead of -1 (I mean, I could use EXT and NEG together, but it's not better and takes up more lines of code). EDIT: also using AND you can get other values like 2 or 4. Convenient f...
by Sik
Mon Jul 02, 2018 2:45 pm
Forum: Megadrive/Genesis
Topic: Random special effects pics
Replies: 7
Views: 702

Re: Random special effects pics

The spheres in the last level of Earthworm Jim 2 (20:03 in the video) https://youtu.be/DVAl6bsJiJY?t=1203 Let's dissect it: https://i.imgur.com/RP52DJd.png https://i.imgur.com/MUSfTKM.png Plane B has a few circles that peek through the gaps in plane A. It just scrolls around to animate it, the inter...
by Sik
Wed Jun 20, 2018 10:08 pm
Forum: Video Display Processor
Topic: How h interrupt register works?
Replies: 7
Views: 701

Re: How h interrupt register works?

Well, two steps ahead is not that problematic (even if a bit annoying)... the problem is what you do the first time - the first two interrupts have to happen with the same interval, no way to avoid that situation.
by Sik
Tue Jun 19, 2018 2:12 am
Forum: SGDK
Topic: Pixel,circle,square and line draw
Replies: 8
Views: 361

Re: Pixel,circle,square and line draw

It just rewrites those sprite entries during hblank interrupts (possibly just the X and Y coordinates - an autoincrement of 6 can help here). Note that you don't need to rewrite them every line (that'd be slow), just fast enough that it matches the difference between two uses of the same sprite (whi...
by Sik
Mon Jun 18, 2018 9:59 pm
Forum: SGDK
Topic: Pixel,circle,square and line draw
Replies: 8
Views: 361

Re: Pixel,circle,square and line draw

I'm doing rain and snow effects for my rpg, I'll analyze if I get more perfomance like this or with tiles. Although I have already seen that the functions are very different from the "line" of the Amiga and Msx. There's a game (forgot the name now) that multiplexes two sprites across the screen and...
by Sik
Mon Jun 18, 2018 1:37 am
Forum: Demos
Topic: wolfenstein demo for sega genesis
Replies: 359
Views: 103261

Re: wolfenstein demo for sega genesis

You could do that using a7 (sp) reg like this: move.b d0, (a7)+ move.b d0, (a7)+ move.b d0, (a7)+ ... because sp reg. autoincrement by 2 even on bytes. But you have to avoid using subroutines (bsr, jsr) and take care of disabling interrupts. Does that work when you need to write to odd bytes? (hone...
by Sik
Sat Jun 16, 2018 6:56 am
Forum: Demos
Topic: wolfenstein demo for sega genesis
Replies: 359
Views: 103261

Re: wolfenstein demo for sega genesis

@kabuto, I'm still not sure if this "byte-wide" DMA has any use for this, because as I read in that document: "just the lower byte of each word written to VRAM will get stored" does that mean that there is no way for the high byte of each word to be read? or is not it? I'll refer to the relevant ef...
by Sik
Sat Jun 09, 2018 6:00 pm
Forum: Video Display Processor
Topic: How h interrupt register works?
Replies: 7
Views: 701

Re: How h interrupt register works?

The counter is reloaded as soon as the interrupt fires, and the register only takes effect when the counter gets reloaded, so yes, it'll only take effect on the interrupt following the next one.

Yes, it's annoying and you have to work around it.
by Sik
Thu Jun 07, 2018 3:29 pm
Forum: Video Display Processor
Topic: disable video on vblank, better?
Replies: 7
Views: 416

Re: disable video on vblank, better?

I think Stef meant the amount of registers per DMA is fixed, which means you could unroll the loop to iterate over every transfer instead of every word. But yeah technically that still isn't correct, it assumes all you do is normal DMA transfers and nothing else (e.g. it won't work if you do "contin...
by Sik
Sat May 26, 2018 7:07 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 175
Views: 9756

Re: Tänzer, a "ninja" game (Dev Diary thread)

Making a dumbed down NTSC version is pretty much guaranteed to cause outrage. Don't do that. Also you'll probably find out that the real issue is that the game is likely unoptimized and there's a lot of opportunity to improve how things are done (and enough to make everything fit in NTSC). Depends ...
by Sik
Fri May 25, 2018 9:54 pm
Forum: Demos
Topic: Tänzer, a "ninja" game (Dev Diary thread)
Replies: 175
Views: 9756

Re: Tänzer, a "ninja" game (Dev Diary thread)

Making a dumbed down NTSC version is pretty much guaranteed to cause outrage. Don't do that.

Also you'll probably find out that the real issue is that the game is likely unoptimized and there's a lot of opportunity to improve how things are done (and enough to make everything fit in NTSC).
by Sik
Sat May 19, 2018 3:05 am
Forum: Megadrive/Genesis
Topic: Random special effects pics
Replies: 7
Views: 702

Re: Random special effects pics

You know, I'm kind against the idea of automatic mipmap generation (e.g. through rescomp?) as you probably want to have some control over how the chunks get split (so you can decide how much trade off you want to have regarding overlap). Remember sprite limits become an issue if you start having a l...