Search found 469 matches

by Miquel
Mon Nov 18, 2019 1:43 pm
Forum: Megadrive/Genesis
Topic: DMA and FIFO
Replies: 11
Views: 2076

Re: DMA and FIFO

Yep, 68k should request the bus on every memory access, and release it when done, except for TAS.
Every memory access takes (a minimum of) 3 cpu cycles.
by Miquel
Sun Nov 17, 2019 7:23 am
Forum: Video Display Processor
Topic: Upload speed on display time
Replies: 2
Views: 239

Re: Upload speed on display time

Ops! I forgot to mention the resolution, currently I’m using 256px mode, but it’s a static parameter, so it can be changed to 320px with no effort. 320px->18 bytes/line 256px->16 bytes/line -> 2 long/128px 4 cycles -> 3.5 px => 128 cycles -> 112 px Well… it seems it fits! The non-buffered version is...
by Miquel
Wed Nov 13, 2019 1:16 am
Forum: Video Display Processor
Topic: Upload speed on display time
Replies: 2
Views: 239

Upload speed on display time

I’m trying to do a map mode, or also known mode 7, on Megadrive/Genesis. So far the best idea I got is to use the idle time, or background “thread”, to upload pixels to the vdp nonstop independently from any synchronism, meaning no vblank will trigger it. This way it uses all idle time for this task...
by Miquel
Fri Oct 25, 2019 10:10 pm
Forum: Demos
Topic: Street Fighter Alpha Mockup
Replies: 17
Views: 2376

Re: Street Fighter Alpha Mockup

On a fighting game both characters are the main and only focus, so half of VRAM sounds good to me; obviously it depends on game’s objectives/priorities. When you say 2x2x7KB, I believe you are referring to uploading half character per frame; that would be the extreme case, the “definitive fighting g...
by Miquel
Fri Oct 25, 2019 6:51 pm
Forum: Demos
Topic: Street Fighter Alpha Mockup
Replies: 17
Views: 2376

Re: Street Fighter Alpha Mockup

I can’t download the ROM so I can’t tell how exactly you did thinks but if I have to do something similar my approach will be clear: During vblank around 7.4KB per frame can be upload to the VDP, so I will reserve a 2x 7KB on VRAM for each character and upload on every frame next character animation...
by Miquel
Wed Oct 23, 2019 5:03 pm
Forum: Collaboration
Topic: Music for Sega homebrew games
Replies: 4
Views: 691

Re: Music for Sega homebrew games

I’m not sure a typical homebrew developer can pay 300 euros per song. I suppose is a matter of reevaluating the project, and decide when is ready to go ahead with music. Do you think a usual artist is willing to listen to criticism and modify its own music to suit better the project? And not the son...
by Miquel
Mon Oct 21, 2019 10:56 pm
Forum: Collaboration
Topic: Music for Sega homebrew games
Replies: 4
Views: 691

Re: Music for Sega homebrew games

As a game programmer the main problem is that a concrete game needs specific tone or themed music. It will be much better to offer a site where both sides can meet and discuss together. Even be involved in the project and share gains,once the tile is launched.
by Miquel
Mon Oct 21, 2019 10:45 pm
Forum: Demos
Topic: Hyrule in Megadrive/Genesis
Replies: 14
Views: 3351

Re: Hyrule in Megadrive/Genesis

Oh! I see what Chilly Willy meant: Earth has too much light from the Sun. Well, you can say that for Mercury, Earth and Mars too, on all of them looking directly at the sun hurts, at different intensities, but the idea is the same. Really the only difference between Earth and Mars is on the last, Su...
by Miquel
Mon Oct 21, 2019 5:27 pm
Forum: Demos
Topic: Metal Blast 2277 - Sega Genesis / Mega Drive
Replies: 54
Views: 13839

Re: Metal Blast 2277 - Sega Genesis / Mega Drive

Well done. Checking what Chinese have to offer is always a good idea. As is today, for example.

As they say "Follow yesterday light to find today's blast"... I'm pretty sure someone in the Universe says that...
by Miquel
Fri Oct 11, 2019 8:50 pm
Forum: SGDK
Topic: Sprite half in front of PLAN_A and the other half behind.
Replies: 8
Views: 786

Re: Sprite half in front of PLAN_A and the other half behind.

The whole effect can be done even better using only one plane: - Launching bombs characters are low priority - Using only plan B with low priority, except for - The tiles which are in front of the bomb launchers - Set black as the background color, and the same color number as index 0 on that palett...
by Miquel
Sat Oct 05, 2019 7:48 pm
Forum: Controls
Topic: New device letters
Replies: 20
Views: 2260

Re: New device letters

Why it seems ugly if it's a byte value? Well, perhaps because it's meant to be read?
In lowercase seems just you forget to push shift. Also some parsers could ignore to upper/lower-case.

But you are the father of the creature after all, do what you think is right.
by Miquel
Sat Oct 05, 2019 12:50 pm
Forum: Controls
Topic: New device letters
Replies: 20
Views: 2260

Re: New device letters

Sik, I think there are two approaches here: a) Every distinct device has its own letter. In that case lowercase is confusing. b) For sake of simplicity let’s group similar devices into groups, same letter if possible, or if there are small differences using letters that are more coincidental. Which ...
by Miquel
Wed Oct 02, 2019 9:56 am
Forum: SGDK
Topic: SRAM read / write
Replies: 12
Views: 903

Re: SRAM read / write

How code (and if applies data) is structured depends on optimization flags, mostly related to cache hit and miss, there is no way to guarantee anything.
by Miquel
Tue Oct 01, 2019 8:20 pm
Forum: SGDK
Topic: SRAM read / write
Replies: 12
Views: 903

Re: SRAM read / write

Another solution is to create a new section and place those functions in this new section. Or reuse other previously created section. The only thing to look after is how sections are ordered. There is no relationship between sections and files, or n<->m relationship if you want. All this is specific...
by Miquel
Tue Oct 01, 2019 3:28 pm
Forum: Controls
Topic: New device letters
Replies: 20
Views: 2260

Re: New device letters

Concerning the 8 button saturn pad on megadrive, I think the key factor is how data is served; if it follows the exact same pattern as 6 button megadrive pad, just two more bits for L and R (or however are labeled on saturn) I think it should add the character “8”. So the string for a game compatibl...