Sponsoring RTG support

mbo77
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Re: Sponsoring RTG support

Unread post by mbo77 »

Forgive my ignorance, but is it functional already somewhere?

robinsonb5
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Re: Sponsoring RTG support

Unread post by robinsonb5 »

mbo77 wrote:
Mon Jul 13, 2020 8:37 pm
Forgive my ignorance, but is it functional already somewhere?
Currently it's only implemented on the Turbo Chameleon 64, which has the same FPGA as the MiST (as opposed to MiSTer) but no supporting host CPU. It shouldn't be too difficult to port to other devices though. (It does also work on the DE10-lite, since I use one of those as a dev platform - but that's a totally different board, not remotely similar to the DE10-nano.)

kolla
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Re: Sponsoring RTG support

Unread post by kolla »

@robinsonb5
Do you have a MiST yourself to test with?

robinsonb5
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Re: Sponsoring RTG support

Unread post by robinsonb5 »

kolla wrote:
Tue Jul 14, 2020 11:00 am
@robinsonb5
Do you have a MiST yourself to test with?
I do, yes - however I had to make some changes when porting the core to TC64 which broke the MiST build in my repo - I haven't got around to un-breaking it yet!

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limi
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Re: Sponsoring RTG support

Unread post by limi »

@robinson5 So can we send you a MiSTer to help out? 😄

robinsonb5
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Re: Sponsoring RTG support

Unread post by robinsonb5 »

limi wrote:
Tue Jul 14, 2020 7:48 pm
@robinson5 So can we send you a MiSTer to help out? 😄
Thanks for the offer - it's much appreciated. However, I think wheels are already in motion to bring a MiSTer my way - I'll let you know if for any reason it doesn't happen, if that's OK?

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limi
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Re: Sponsoring RTG support

Unread post by limi »

Great! Just let us know 😄

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Sorgelig
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Re: Sponsoring RTG support

Unread post by Sorgelig »

Recent MiSTer framework supports framebuffer from DDR3 supplied by core. So the proper way for RTG is to use framebuffer.
Basically it's just another memory region in DDR3 (left some space in DDR3 exactly for RTG). For me, the hardest part is Amiga side, not HDL. Resolution on RTG for MiSTer isn't a problem. Up to 1920x1080 can be easily supported.
Modification is SDRAM is not required. SDRAM is only for Chip RAM.

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uigiflip
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Re: Sponsoring RTG support

Unread post by uigiflip »

limi wrote:
Wed Jul 15, 2020 11:01 am
Great! Just let us know 😄
checking if the care package has departed lol
MiSTer Ultimate, MiSTer Ultimate LL Cool Joy version, Replay Vidor version, Replay 2, Real Amiga's 500, 500 plus, a1200 and cd32.

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uigiflip
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Re: Sponsoring RTG support

Unread post by uigiflip »

Checked will be dispatched next week
MiSTer Ultimate, MiSTer Ultimate LL Cool Joy version, Replay Vidor version, Replay 2, Real Amiga's 500, 500 plus, a1200 and cd32.

robinsonb5
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Re: Sponsoring RTG support

Unread post by robinsonb5 »

Sorgelig wrote:
Sat Jul 18, 2020 10:25 pm
For me, the hardest part is Amiga side, not HDL. Resolution on RTG for MiSTer isn't a problem. Up to 1920x1080 can be easily supported.
Well having done it once, the software side's easy for me now.
With the framebuffer approach, does the Amiga still need to set up a CRTC frame with sync/blank counters, or is that all handled host-side with the MiSTer framework?
Modification is SDRAM is not required. SDRAM is only for Chip RAM.
Sure - I did say that would be necessary for a *direct port* of what I already have working - but I realise on the MiSTer there's a better approach.

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Grabulosaure
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Re: Sponsoring RTG support

Unread post by Grabulosaure »

@robinsonb5

The idea is to use the scaler to generate the image. You provide image size, colour depth, base address and a switch to activate the thing and it will display your framebuffer instead of the existing MiniMig core output. This is how the framebuffer mode (F9 from menu) works.
(colour depths are 256c indexed, 16bits 565 RGB, 24bits RGB, 32bits RGB_)

Constraint is that line length is rounded to 256 bytes (example 800 pixels, 24bits = 2400 bytes => 2560 bytes per line)

robinsonb5
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Re: Sponsoring RTG support

Unread post by robinsonb5 »

uigiflip wrote:
Sun Jul 19, 2020 9:24 am
Checked will be dispatched next week
Awesome - many thanks for that.
Grabulosaure wrote:
Sun Jul 19, 2020 8:48 pm
The idea is to use the scaler to generate the image. You provide image size, colour depth, base address and a switch to activate the thing and it will display your framebuffer instead of the existing MiniMig core output.
OK, so the timings created in Picasso96Mode will be irrelevant - only the dimensions and pixel format will be needed.
Constraint is that line length is rounded to 256 bytes (example 800 pixels, 24bits = 2400 bytes => 2560 bytes per line)
OK, I've just done a quick test and it doesn't look like rounding up the row size will be a problem.

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Sorgelig
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Re: Sponsoring RTG support

Unread post by Sorgelig »

robinsonb5 wrote:
Sun Jul 19, 2020 9:40 pm
OK, I've just done a quick test and it doesn't look like rounding up the row size will be a problem.
ascal has been changed already current version in template has stride granularity of 16 bytes so it should be not a problem for RTG resolutions.
Soon it will be updated with 1 pixel granularity.
I'm currently working on SVGA in ao486 which is basically similar to RTG on Amiga and uses framebuffer in DDR3.
robinsonb5 wrote:
Sun Jul 19, 2020 9:40 pm
OK, so the timings created in Picasso96Mode will be irrelevant - only the dimensions and pixel format will be needed.
Yes and no. HSync/Vsync has to be generated anyway from the core as scaler does sync to video. So basically scaler needs to know how fast to draw the video. But anyway it can be simplified as you don't need to generate blanking. Just HSync/Vsync will be enough.

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Grabulosaure
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Re: Sponsoring RTG support

Unread post by Grabulosaure »

@robinsonb5
@sorgelig
When using vsync_adjust=2, the scaler (actually a separate block in sys) tries to synchronise input video with scaled output. If the framebuffer mode is used, that same block willl still try to synchronize video, even if the "input video" isn't displayed anymore.
I don't know how RTG boards work, but if some boards used synchro pulses as interrupts, or for double buffering, then the hsync/vsync signals generated by the scaler will be needed as inputs.

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Sorgelig
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Re: Sponsoring RTG support

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Grabulosaure wrote:
Wed Jul 29, 2020 11:44 am
@robinsonb5
@sorgelig
When using vsync_adjust=2, the scaler (actually a separate block in sys) tries to synchronise input video with scaled output. If the framebuffer mode is used, that same block willl still try to synchronize video, even if the "input video" isn't displayed anymore.
I don't know how RTG boards work, but if some boards used synchro pulses as interrupts, or for double buffering, then the hsync/vsync signals generated by the scaler will be needed as inputs.
this is why i've wrote above that even in framebuffer mode the core should generate the hsync/vsync.
Getting sync signals from output video back to core is not an universal solution. Some cores may also need hblank/vblank for internal work. Also core may need to generate specific refresh rate instead a standard. So it's better if core will generate hsync/vsync (together with other sync signals if required) and then scaler will sync to it (if asked) as usual.

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Grabulosaure
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Re: Sponsoring RTG support

Unread post by Grabulosaure »

@sorgelig @robinsonb5
Besides HSYNC/VSYNC, The DE "Display Enable" is needed for synchronisation (because the scaled image must be aligned with the top or bottom of the input image.

The transparent multi-buffering done by the scaler isn't available in framebuffer mode.
Many options are available, such as ignoring synchronization and allow tearing, or use HDMI sync signals to software in RTG mode, or using that synchro for transparent multi-buffering : This is how works the GBA core in framebuffer mode, using the signal fb_vbl = hdmi_vblk, to synchronize multi-buffer switch with HDMI output : The software always has the original vertical frequency independantly from HDMI video mode, and double-buffering is done by the core instead of the scaler.

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Sorgelig
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Re: Sponsoring RTG support

Unread post by Sorgelig »

Right. This is again toward my original post - core needs to generate its sync signals in framebuffer mode. So it will control multiple buffers itself and scaler will follow the vsync.

kolla
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Re: Sponsoring RTG support

Unread post by kolla »

Is it at all possible to simultaneously have different outputs on the HDMI and the IO-board analogue port, or are they very much linked together?

Fularu
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Re: Sponsoring RTG support

Unread post by Fularu »

kolla wrote:
Thu Jul 30, 2020 1:04 pm
Is it at all possible to simultaneously have different outputs on the HDMI and the IO-board analogue port, or are they very much linked together?
Like RTG via HDMI and 256p via RGB out?

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Grabulosaure
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Re: Sponsoring RTG support

Unread post by Grabulosaure »

Typically the analog out port can display "normal" Amiga video (OCS/ECS...) while HDMI will display the RTG output.

kolla
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Re: Sponsoring RTG support

Unread post by kolla »

“Typically” on real Amiga, yes, but this is MiSTer, it already displays native modes on HDMI, and the analogue port seems to mirror what’s on the HDMI, so I suspect it’s not possible to seperate them.

robinsonb5
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Re: Sponsoring RTG support

Unread post by robinsonb5 »

Thanks for the useful info, Sorgelig and Grabulosaure.
kolla wrote:
Fri Jul 31, 2020 10:47 am
“Typically” on real Amiga, yes, but this is MiSTer, it already displays native modes on HDMI, and the analogue port seems to mirror what’s on the HDMI, so I suspect it’s not possible to seperate them.
I get the impression that it's the other way around - the HDMI normally mirrors what's on the analogue port, but doesn't have to - for RTG mode it can be made to display something different instead.

apolkosnik
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Re: Sponsoring RTG support

Unread post by apolkosnik »

kolla wrote:
Thu Jul 30, 2020 1:04 pm
Is it at all possible to simultaneously have different outputs on the HDMI and the IO-board analogue port, or are they very much linked together?
Although I'm sporting a monitor that can take 15kHz on the VGA, and does auto-switching between these inputs (Acer G276HL Kbix). Having additional options is always pretty cool.
In most cases, you end up with one of these screens displaying nothing but the static. I would imagine that the most people using de10-nano are either plugging a modern HDMI monitor or CRT for the VGA (if they have the analog IO board).

Though, you can't expand out the WB over two screens, like in windows. You can however run one program on screen1 and second program on screen 2 at the same time.

SpringMaus is a small utility for using 2 monitors with AmigaOS
http://www.steamdraw.homepage.t-online.de/

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Sorgelig
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Re: Sponsoring RTG support

Unread post by Sorgelig »

In Russia we call it as "Splitting the skin of not yet killed bear."

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