Search found 80 matches

by Manveru
Sat Jun 06, 2020 2:43 pm
Forum: Sound
Topic: Sega CD Mode 1 support functions for SGDK
Replies: 25
Views: 9036

Re: Sega CD Mode 1 support functions for SGDK

I suppose that after a certain amount of time, or if the user selects something from the menu to disable the cd, you could reset the asic and the sub cpu. That should do it. /* * Reset the Gate Array - this specific sequence of writes is recognized by * the gate array as a reset sequence, clearing ...
by Manveru
Thu Jun 04, 2020 11:08 pm
Forum: Sound
Topic: Sega CD Mode 1 support functions for SGDK
Replies: 25
Views: 9036

Re: Sega CD Mode 1 support functions for SGDK

Emulators generally don't handle things like Mode 1 since it wasn't used by anything commercial, so it was of no interest to emulator authors. It's like CD32X emulation - not something emulations handle. This is more a real hardware thing. Yeah, but finally Kega can be used for testing if you do no...
by Manveru
Thu Jun 04, 2020 4:16 pm
Forum: Sound
Topic: Sega CD Mode 1 support functions for SGDK
Replies: 25
Views: 9036

Re: Sega CD Mode 1 support functions for SGDK

Now i see this thread up, i wonder if there is any tutorial or else to make "Mode 1" (sorry Sik) work in emulators. I tried with Kega but it has some glitches that does not draw the graphics after loading the CD. It is suppose to work with Genesis plus gx, but i can not find any guide for that, so a...
by Manveru
Fri Dec 06, 2019 9:17 am
Forum: Video Display Processor
Topic: Horizontal Cell Scroll + Vertical Plane Scroll
Replies: 4
Views: 7738

Re: Horizontal Cell Scroll + Vertical Plane Scroll

Could it be that vdp hardware applies first vertical scroll and only then horizontal? If that’s the case, since there is no way to exchange priorities, I don’t think there is a solution, one of both scrollings has to be first. it is possible and i also can not find a solution so we decided to set h...
by Manveru
Tue Dec 03, 2019 9:55 am
Forum: Video Display Processor
Topic: Horizontal Cell Scroll + Vertical Plane Scroll
Replies: 4
Views: 7738

Re: Horizontal Cell Scroll + Vertical Plane Scroll

Your post is extremely confusing, not sure I understood it at all, but let’s give it a try. You can only scroll 28 tiles because that’s the max resolution on NTSC (28 * 8 = 224). The questin was if it is possible to make properly a horizontal cell scroll when the vertical scroll is moving. Horizont...
by Manveru
Mon Dec 02, 2019 9:43 am
Forum: Video Display Processor
Topic: Horizontal Cell Scroll + Vertical Plane Scroll
Replies: 4
Views: 7738

Horizontal Cell Scroll + Vertical Plane Scroll

I come from this topic but i do not know very well how it works and if the same applies to horizontal scroll: http://gendev.spritesmind.net/forum/viewtopic.php?f=22&t=737 In short: i have a cell (tile) scroll for a 36 tile height background. When vertical scroll is 0, then the background horizontall...
by Manveru
Thu Jul 11, 2019 4:58 pm
Forum: Video Display Processor
Topic: DMA Fill with autoinc 128
Replies: 3
Views: 2968

Re: DMA Fill with autoinc 128

See official documentation for an explanation; see SGDK code implementation for a solution. Fill basically works only with bytes when transferring, so both bytes of the map have to be the same; this will only work if you intend to use the very first tile as a substitute with all flags to 0 (everyth...
by Manveru
Thu Jul 11, 2019 1:43 pm
Forum: Video Display Processor
Topic: DMA Fill with autoinc 128
Replies: 3
Views: 2968

DMA Fill with autoinc 128

Hello mates. I think what i wanted to do is not possible due to how DMA Fill works, but i want to ask you before definitely discard that idea. I want to clear an image in a plane, column by column. Then my first thought was to do a DMA Fill of 0s from the corresponding plane nametable pattern coordi...
by Manveru
Fri Jan 18, 2019 12:11 pm
Forum: Video Display Processor
Topic: Help scale and rotation sega genesis
Replies: 33
Views: 13067

Re: Help scale and rotation sega genesis

Some time ago we made some tests with scaling and rotation, and as Sik said, it is very very expensive. Anyway, i you want or need to make some basic stuff in intros or something like that, we used this guide with as much optimizartions as we could: http://www.drdobbs.com/architecture-and-design/fas...
by Manveru
Sun Dec 23, 2018 11:05 am
Forum: Tools
Topic: Fork of DMF2ESF (Deflemask to Echo converter)
Replies: 10
Views: 6722

Re: Fork of DMF2ESF (Deflemask to Echo converter)

I hope someone can help us. We need some stuff to convert from a tracker to Echo, and Deflemask + your converter seems to be the best chance. Hi. I made an app to convert DMF to Echo's format. It's call "DefleMask Convert" and it's in the Tools section. You should try it. Thanks for your work mate,...
by Manveru
Sun Dec 02, 2018 2:32 am
Forum: SGDK
Topic: XGM Driver issue
Replies: 21
Views: 4942

Re: XGM Driver issue

As after some weekend party is a great moment for coding xD, i decide to check a bit the "volatile" pointers causing the issue. I tested adding a "volatile" keyword to every var accessing memory, and (at least in emulators Blastem and KMod, can't test in real hardware) i can make music samples sound...
by Manveru
Tue Nov 20, 2018 6:27 pm
Forum: SGDK
Topic: XGM Driver issue
Replies: 21
Views: 4942

Re: XGM Driver issue

I am using gcc 8.2 but i did my tests also with gcc 6.3 and 7.2, and with all of them i have the issue.
Probably one day i will try to make some performance test with different gccs, it can be interesting.
by Manveru
Tue Nov 20, 2018 12:32 pm
Forum: SGDK
Topic: XGM Driver issue
Replies: 21
Views: 4942

Re: XGM Driver issue

I had no idea about memory barriers. It is common not to find much info about 68k and gcc, and it is usually a problem. I hope Stef and the people like you who know about that stuff can improve SGDK and let us learn about that good behavior programing for the mega drive.
by Manveru
Mon Nov 19, 2018 3:30 pm
Forum: SGDK
Topic: XGM Driver issue
Replies: 21
Views: 4942

Re: XGM Driver issue

Ohh.. again a compiler optimization issue, generally optimization issue are caused by missing "volatile" keyword on port access. It also may be related to your "wait" loops. I observed for instance that in some situation the VDP_waitVSync() method may be optimized by the compiler so that the next l...
by Manveru
Mon Nov 19, 2018 2:46 pm
Forum: SGDK
Topic: XGM Driver issue
Replies: 21
Views: 4942

Re: XGM Driver issue

while(!Z80_isDriverReady()) while(Z80_isBusTaken()); You DO realize that Z80_isBusTaken() merely checks if the 68k has halted the Z80? That "while(Z80_isBusTaken());" either does nothing, or it hangs forever, depending on if the Z80 has been halted. Yes, that is the problem, the question is why tha...