MSX HDMI mutlimedia card

Страница 33/56
26 | 27 | 28 | 29 | 30 | 31 | 32 | | 34 | 35 | 36 | 37 | 38

By maxis

Champion (512)

Аватар пользователя maxis

24-07-2015, 19:13

fernando.collazo.5682 wrote:

Forgive me my ignorance, can´t you put a simple switch to change 50/60 Hz?
Here in Brazil, 60Hz is ok for almost all MSX software, but some european games and demos, they run too fast and we can't appreciate them in the proper way how are to be.
Perhaps is too much trouble, but europeans are a huge MSX fan base and will be a potential customers of Procyon.

Hello,
When the card is used like OCM, then no problem, it's easy, no genlock.
In the MSX extension mode (in parallel with the built-in VDP), the card has to genlock its HDMI video output to the MSX video output. Technically it's a very difficult engineering task. The 50Hz limitation comes from the availability of the 50Hz/100Hz HDMI screen modes in the modern monitors. Only HDTVs do support such modes.
There are 2 ways displaying the MSX screen over HDMI:

1. Genlocked mode, where the HDMI gigabit serial pixel stream is perfectly locked to the MSX VDP built-in crystal oscillator. MSX raster matches the HDMI raster timing. No artifacts are produced.

2. Free scanning mode, where the HDMI refresh rate is fixed to 60/75 or 120Hz, but the original frame rate can switch between 50 and 60Hz. This mode produces the artifacts on the moving images, like the lag and "broken" raster.

Currently I try to achieve a breakthrough in the first method. If I'll fail, I'll use the method 2.

By syn

Paragon (1983)

Аватар пользователя syn

24-07-2015, 20:39

maxis wrote:
syn wrote:

Btw I somehow missed some info about this thing, I thought it was just a msx1 hdmi out cartridge so I didn't really paid attention to this thread Big smile

I just browsed your site, the project it looks pretty amazing Big smile

Thanks. Last December the card could do the MSX1 HDMI out + PSG/SCC audio emulation + memory extension. However, for about 7 months I'm working on the HDMI genlock, which is a difficult task.
If HDMI genlock idea is operational, then I can do the MSX2 VDP emulation. Otherwise I'll resort to the free scanning, but it is not so good, since this method produces the artifacts.

Current project plan:
- Finalize the current VGA mode HDMI genlock;
- Implement the stand-alone MSX1;
- Implement the stand-alone SMS;
- Design and validate the multi-mode 50/60Hz genlock;
- Finalize MSX2 VDP command engine.
etc.

I see. From what I understand from your site you can basically upgrade any MSX1 or 2 to a 2+ with SD card reader, scc and 4MB ram, thats pretty sweet I think if you get it working. Also stand-alone use is pretty nice Big smile

About Unknown Reality, I dont know the specifics about that. Bifi posted a video on youtube and he mentioned about the 50/60hz switch causing problems with the recording. https://www.youtube.com/watch?v=jqv9drS3wGQ He also provides a link about how he recorded the video.

My guess is that the switch happens in between the ending and start of parts/chapters, but I am really just speculating here.

By Manuel

Ascended (17064)

Аватар пользователя Manuel

24-07-2015, 20:54

UR switches while loading.

By maxis

Champion (512)

Аватар пользователя maxis

25-07-2015, 00:27

syn wrote:

From what I understand from your site you can basically upgrade any MSX1 or 2 to a 2+ with SD card reader, scc and 4MB ram, thats pretty sweet I think if you get it working. Also stand-alone use is pretty nice Big smile

About Unknown Reality, I dont know the specifics about that. Bifi posted a video on youtube and he mentioned about the 50/60hz switch causing problems with the recording. https://www.youtube.com/watch?v=jqv9drS3wGQ He also provides a link about how he recorded the video.

My guess is that the switch happens in between the ending and start of parts/chapters, but I am really just speculating here.

Manuel wrote:

UR switches while loading.

Thank you guys,

The thing is that any HDTV will blank the screen for at least 0.5 sec when receiving the mode change... Initially I planned to mix audio into the HDMI, but since on the mode change the HDMI sound is cut too, then now audio is going through analog output and TOSLINK. I.e. uninterrupted.

If there is the absolute requirement to provide 50/60Hz seamless and instant mode changes, then, unfortunately, I've got to use the double buffered video output with the fixed HDMI format.

Are these fast mode changes really necessary to support?

By syn

Paragon (1983)

Аватар пользователя syn

25-07-2015, 01:09

It depends on your vision imho, do you want 100% perfect compatibility/emulation?

Some demos have interrupt mode switchers https://www.youtube.com/watch?v=XGxpXluGBhU https://www.youtube.com/watch?v=3hpsB9jkyJE

In my opinion interrupted music isnt that bad during selection screens, since the image will go blank by default because of the tv/monitor. and I would just accept it as a part of the "mode change". But other ppl would probably complain.

I don't know if there are other software that have mode change in other places than at start. I am curious also. I havent read the complete topic, double buffer is slower I guess (latency)? Would it be possible to select it through a Jumper or something? Personally I wouldnt mind if one or 2 demos dont work perfectly and would prefer less latency instead, but I am really not a purist (I dont care about scanlines/perfect CRT emulation either, I am perfectly fine with, probably even prefer, just a sharp upscaled image with correct aspect ratio), but this depends if people can answer above the question (what other software have this mode change in other places than at start?)

By Grauw

Ascended (9379)

Аватар пользователя Grauw

25-07-2015, 02:06

maxis wrote:

Are these fast mode changes really necessary to support?

No, it’s not important at all. Frequency switches typically don’t happen frequently. My TFT monitor also blanks out for 0.5 seconds when I switch between 50/60Hz, never been a problem. Any PC does this too. It’s just how things work with modern screens (quite oddly Smile). Audio dropping out is also not a problem, I would prefer audio through HDMI or even better, through all the outputs.

By yzi

Champion (444)

Аватар пользователя yzi

25-07-2015, 03:26

maxis: sorry for making you feel insulted. My concern is not standards compliance at all, but rather the way 1980s machines are currently presented: having big perfectly square pixels filling the screen without scanlines, and jerky motion. They didn't look like that, because of the CRT monitor. Take the essential CRT image qualities away, and its a mockery of what people fell in love with. In my honest opinion. A proper retro video game pixel must not look like a square. The thought of a retro machine that directly outputs a square-pixel atrocity via HDMI, without trying to do any sort of CRT simulation is ... frightening. Frankenstein is the closest word I could think of. The forced line-doubling should at least be straight-forward to get rid of?

Hardware design must be incredibly hard, so all credit to you, very ambitious project.

By gdx

Prophet (3814)

Аватар пользователя gdx

25-07-2015, 07:13

For me, as long as the image is clean and that the proportions are respected, I am satisfied. The CRT simulation is only a gadget, sometimes welcome, sometimes annoying. This is rarely done well anyway.

Grauw wrote:

Frequency switches typically don’t happen frequently. My TFT monitor also blanks out for 0.5 seconds when I switch between 50/60Hz, never been a problem. Any PC does this too.

+1

By maxis

Champion (512)

Аватар пользователя maxis

06-09-2015, 16:16

Hello,

A short update:

MSX HDMI genlock is finally successfully implemented!
Next demo to come -> Synthesix with its perfectly stable image generated from VDP line interrupts.

I do have a concern however:
machines with built-in digitizer could have some problems (no HDMI image) if the PLL generated clock source is too jittery (V7010 based computers like Daewoo CPC400s & Philips NMS8280 generate the VDP clock from 3.579545 MHz crystal).

By maxis

Champion (512)

Аватар пользователя maxis

12-01-2016, 02:44

Project update:

Full V9938 support including the screen modes, sprite mode2, command engine is added. Also HDMI genlock now automatically detects the current MSX video mode. All the 8 scan modes are supported on the fly:
- 50/60Hz;
- Intelaced/progressive;
- 1368/1365 clocks per scanline.

Interesting fact: this genlock architecture doesn't use the intermediate frame buffer/comb filter. So, for the user no difference will be seen between old-style analog CRT and modern HDTV.

Running at 50Hz. Splash screen from Toshiba FS-TM1

Space Manbow switches the screen mode to 60 Hz:

Страница 33/56
26 | 27 | 28 | 29 | 30 | 31 | 32 | | 34 | 35 | 36 | 37 | 38