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Gunnar von Boehn
Germany
| | (Natami Team Member)
Posts 3727
24 Sep 2009 13:52
| Claudio Wieland wrote:
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Gunnar von Boehn wrote:
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Claudio Wieland wrote:
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The system can display up to 1280x1024. Which means that at 60Hz this is about 78.6 MHz pixel clock.
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1280x1024@60Hz is about 108 MHz Pixel-Clock
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How? My calculator says: 1280x1024x60 = 78,643,200 px/sec . Do I make a mistake here? Something I forgot?
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you forgot to add the sync timings :-) Here some pixel cocks:
640x480@60 = 25 mhz
800x600@60 = 40 mhz
1024x768@60 = 65 mhz
1280x1024@60 = 108 mhz
1600x1200@60 = 162 mhz Here is an online calculator:
EXTERNAL LINK
cheers
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Claudio Wieland
Germany
| | (Natami Team Member)
Posts 364
24 Sep 2009 14:07
| Sou desu ka. Thank you very much, Gunnar :-) .
So, 1080p might be a bit far out ^^ . Maybe you can do some magic tricks to get the system clock up to 182.5MHz ? lol. Maybe some better future FPGA might do the trick.Or maybe some scandoubling on 1080i .. ?? Who knows. But you.
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Marcel Verdaasdonk
Netherlands
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Posts 2089
24 Sep 2009 14:13
| oops, i see that i have miss calculated. (I used the number of pixels twice...)
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Christian Kummerow
Germany
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Posts 171
24 Sep 2009 15:06
| Gunnar von Boehn wrote:
| | you forgot to add the sync timings :-)
Here some pixel cocks:
640x480@60 = 25 mhz
800x600@60 = 40 mhz
1024x768@60 = 65 mhz
1280x1024@60 = 108 mhz
1600x1200@60 = 162 mhz |
Most Amiga users buy anyway TFTs that support 50HZ Refresh
then we are on 1600x1200@50=135 MHZ. It don^t flicker because
of the TFT technic.
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Marcel Verdaasdonk
Netherlands
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Posts 2089
24 Sep 2009 15:27
| Hm, i think i should be posible to show a image twice before refreshing it.
This would reduce the bandwidth need too.
And this would word for most films too since they only would have what 25 fps?(PAL)
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Claudio Wieland
Germany
| | (Natami Team Member)
Posts 364
24 Sep 2009 16:20
| Marcel, you are forgetting that video data is a continuous stream of DRAM data. You would need to buffer a whole image in - guess what - a *fast* RAM. And as e.g. external SRAM does not seem to give any real advantage in comparison to DDR2, this effort is useless. So there is no bandwidth reduction at all, since there is no dedicated frame buffer whatsoever. Never was. And probably is not worth the cost.
As I mentioned, I could imagine a solution where 1080i at 60Hz is scandoubled. Half the bandwidth for a not-so-crappy picture, IMHO. And if someday (soon?) some really fast FPGA comes out, an additional 1080p mode could be added.
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Gunnar von Boehn
Germany
| | (Natami Team Member)
Posts 3727
24 Sep 2009 18:15
| gees what is the bandwidth problem with 1080p at all?
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Thomas Hirsch
Germany
| | (Natami Team Member)
Posts 233
24 Sep 2009 18:59
| As already said the NatAmi will work in an AMIGA like fashion, not like a PC GFX card with fixed video modes. On the Amiga there are only two limiting factors for display resolution. The DMA bandwidth to chip ram and the pixel clock. Nothing more.
The resulting screen resolution is defined by the monitor driver in DEVS:
As this is the bringup thread I will tell here when any DMA actually works. As I can tell for now is that the DMA performance greatly depends on the memory controller and it's schedule.
Ram has gotten very fast. But the big disadvantage is that accesses have to be scheduled or (the better word is) interleaved. The original Amiga design processes one access after the other. To get a reasonable performance increase I/we need to change this. This means that the access arbitration part will increase.
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Guillaume Michalakakos
France
| | (Natami Team Member)
Posts 144
24 Sep 2009 20:27
| New pictures : NatAmi LX with NAe60R are available in the hardware section and they are very nice ^^
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Joe M
Norway
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Posts 164
24 Sep 2009 20:51
| Thomas Hirsch wrote:
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The resulting screen resolution is defined by the monitor driver in DEVS:
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Does this mean that the Natami's new resolution modes will only work from
Workbench like external Amiga graphic cards?
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Channel Z
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Posts 213
24 Sep 2009 20:52
| @Joe I would guess that the modeid can be set in the usual way too.
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Claudio Wieland
Germany
| | (Natami Team Member)
Posts 364
24 Sep 2009 21:18
| It's just.. another.. mode.. ^^ . Set the right bit-> wee!
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Thomas Hirsch
Germany
| | (Natami Team Member)
Posts 233
24 Sep 2009 22:21
| @Joe
no.
The new resolutions will not only, but also work from Workbench. The new modes are available by programming the ECS registers @ $DFF1C0 through $DFF1E4. This is what the monitor drivers in DEVS: are for.
External Amiga graphic cards can not run on Workbench directly. They need an RTG layer like CyberGraphX or P96 as they do not have any ECS registers.
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Joe M
Norway
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Posts 164
25 Sep 2009 02:06
| Good to hear :) I've never been a fan of external Amiga graphic cards because of the RTG layer. I was afraid the Natami's new resolution modes would need a CyperGraphX or P96 driver to work as well, but now I know better :) Thanks.
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Istvan Szekeres
Hungary
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Posts 23
26 Sep 2009 12:55
| BEAUTYFULL! THE DREAMS COME TRUE...
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Andreas G. Szabo
Germany
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Posts 102
26 Sep 2009 15:18
| Istvan Szekeres wrote:
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BEAUTYFULL! THE DREAMS COME TRUE...
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Well, annother hungarian. szia!
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Dag Jacobsen
Norway
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Posts 47
27 Sep 2009 05:28
| What I really meant was that how will the fact that most old games are 4:3 screen format and not 16:9 or 16:10 be handled ? Most LCD computer screens have no facility for changing this.. So the image will be stretched :-(
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Jacek Rafal Tatko
Espania
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Posts 515
27 Sep 2009 06:24
| Hello Marcel, even if... in Games at 25fps this would mean e.g. blurry moves of fast bullets and shots.. some games like turrican were coded at 50fps for that reason... even tennisgames like Great Courts II ... many others true pal is 50hz Disclaimer: *if i am wrong it is because i smoked a song* oo
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Marcel Verdaasdonk
Netherlands
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Posts 2089
27 Sep 2009 12:14
| Jacek your right about PAL being 50hz, but Pal movies are generaly in a lower frame rate. I myself loath playing games in the highest resolution, especialy FPS games.
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Mr Copland ;)
United Kingdom
| | (Natami Team Member)
Posts 452
27 Sep 2009 14:38
| Marcel Verdaasdonk wrote:
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I myself loath playing games in the highest resolution, especialy FPS games.
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Nah, you just need a faster computer :P (joke!)
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