OSSC (Open Source Scan Converter) with an Amiga

[drHirudo]

Originally Posted by Jope

This is your grabber doing the rolling, OSSC cannot help unfortunately, since it is not a scaler. It will not be able to adjust the vertical refresh for you.

I've found a fix for the vertical rolling issue! When I select the Screen Mode to be interlaced, the Amiga outputs at exact 50 Hz vertical refresh rate, which works fine with the framegrabber.
This works pretty good for Workbench and applications that allow selecting a Screen Mode. For other applications if they don't close Workbench there is still a way to fix it refresh rate:

[ Show youtube player ]

There are even some games that accept screen mode promotion, one most popular example that I remember from the past being Simon The Sorcerer.

Unfortunately there is still no fix for the games that boot directly or close Workbench, which is around 90% of the Amiga games.

P.S.:

Workbench and Music-X recording with the Framegrabber:

[ Show youtube player ]

[ Show youtube player ]

[Grassini]

Hi, does anyone have saved profiles in the json file and would be so helpful to make the saved profile appear (compatible with firmware 0.88).
Thank you very much

[Foul]

is the Pro version out ??? many OSSC-X Pro on Aliexpress ?? WTF ???

https://fr.aliexpress.com/item/4001280244469.html

Real version

[Retro-Nerd]

Nah, the Pro isn't out yet. The device would cost much more anyway from what i've read. The Pro also will have HDMI in. Can't see this on the Aliexpress pics.

[Foul]

Ok thx !

[quantum8]

Does anyone know how to adjust the vertical size so that it fits on my monitor without cutting off the lower area of the screen?

It makes games like Pinball Dreams and Furtum Sanctum a bit hard to play!
I'm using the first set of parameters:
H Sample: 908
H fraction: .00
H. Synclen: 60
H Backporch: 76
H Active: 724
V Synclen: 3
V Backporch: 25
V Active 288
phase 180.

I've tried adjusting the various V parmaeters as well as the line modes from 2-4x , generic 4:3, as well as the various modes for each lineX.

I'm a bit lost on how to properly setup the size parameters here.

[Jope]

Originally Posted by quantum8

Does anyone know how to adjust the vertical size so that it fits on my monitor without cutting off the lower area of the screen?

It is a sum of many things. I don't have my OSSC here so this is based on memory and the junkerhq menu listing.

First set the Amiga to the mode you want to tweak.

Press the info button on the OSSC remote and see what mode is applied. The default display might show 313p or something, but this is the input mode. After you press info, you can see the output mode.

Now that you see what mode the OSSC is applying to the signal, you can tweak that mode. First go to Output Opt. and select the same resolution as was displayed in the info screen, such as 240/288p proc if it was in a 288p mode. You select the multiplication here depending on your monitor's resolution. Line2x is always visible, so let's choose this for the time being. Same steps but different selections if you want a different multiplication.

Now that you have selected a multiplication mode, you have to go to "Line2x mode", still under Output Opt. Here you must select one of the processing modes. Generic 4:3 is the default, but this will not allow any adjustments. Now you should make an educated choice, but since the timings given here are from a time when there wasn't this much choice, go with 256x240 optim, as that was the one we had back then.

Ok, now you have set up the pipe for the output mode and it is actually tweakable.

Now you can go check the info screen again to see which timing mode you should adjust. Go to Adv. Timing and select that timing mode and enter the values you posted in your message. V. Active = 288 should already be correct.

[quantum8]

Thanks Jope, it's a start. The info screen shows it's using 263p and using the preset of 320x240.

It seems all the processing modes are limited to 240lines which I'm guessing is why I am seeing the lower section of the picture being drawn outside the lower boundary of my screen.

[Jope]

The numbers in the processing mode shouldn't matter in this case. What kind of monitor do you have connected?

[Retro-Nerd]

Looks like your monitor is in 60Hz mode, hence the 240p output. For PAL 288p you need 50Hz.Yep, 313p in the OSSC info screen is correct for PAL.

[Jope]

You may be right as in the Amiga being in NTSC mode. 263p is a lot less than what mine shows.. in PAL mode it is 313p as the input mode.

Is PB Dreams off floppy or WHDLoad?

[Retro-Nerd]

These are my OSSC PAL Amiga settings (49.92Hz), in Line 4x mode/Generic 4:3. I use 270 for V.active because it gives you a perfect 1080p output. Most Amiga stuff doesn't use more than 272 vertical anyway. Good enough for Pinball Dreams too. 1440p for H.active gives you a perfect 4:3 output (on Full HD & 4K displays). H/V backporch and synclen may differ, depending on the monitor/TV.

[quantum8]

Now there's something I didn't consider! I've checked the mode of the machine and forcing it to PAL. It's picking up the correct settings now, centred and all. Thanks guys!

[MoonDragn]

Anyone know if there is a way to get the OSSC to output to exactly 1080p standards? I can't get it to show up on my USB-C only monitor using a SIIG hdmi to USB-C converter.

I can use a cheap composite to hdmi converter in 1080p with this but can't seem to get the OSSC to match the signal. Do I need to get an hdmi video processor on top of the OSSC to get it to output correctly?

My Amiga is connected to the ossc using an RGB to VGA adapter.

[Jope]

Probably "impossible" as the vertical refresh frequency is dependent on the input frequency.

If your application requires a scaler, you should look at the framemeister instead.

[Herpes]

Hm, since the OSSC described in the posts looked so good I just bought my own device - it has the fw. 0.86a - but unfortunately I am too dumb to operate it

Can anyone and tell me what to do to get this baby running with the Amiga500?
I just plugged in the usual RGB-SCART cable from my 1082 into the OSSC-device and set the input to AV1(RGSBS).

It syncs - and on the OSSC-panel are two lines displayed.
AV1_RGSBS 313-p
15.61kHz 49.89 Hz

My monitor tells me that the current signal has a non supported frequency - but nothing else.

On start-up - the OSCC displays a nice grey test screen and it look superb.

Is my old and trusty monitor Acer B273HU already too old, or do I need to change some settings?

Thanks for any hints!

[MoonDragn]

Originally Posted by Jope

Probably "impossible" as the vertical refresh frequency is dependent on the input frequency.

If your application requires a scaler, you should look at the framemeister instead.

can I put the output of the ossc through this thing: ?


https://www.amazon.com/Monoprice-Bla...5072832&sr=8-3

[Jope]

Originally Posted by Herpes

Is my old and trusty monitor Acer B273HU already too old, or do I need to change some settings?

Most likely your monitor can't do 49.92Hz vertical. You can try Line3x or Line4x if your monitor has enough resolution, but none of these affect the frequency.

[Jope]

Originally Posted by MoonDragn

can I put the output of the ossc through this thing: ?


https://www.amazon.com/Monoprice-Bla...5072832&sr=8-3

I believe you can, but why use an OSSC at all in this signal chain? First you have the OSSC that is capable of perfect input <-> output frequency matching and pixel perfect sampling.

Then the signal goes to this converter which blurs the pixel perfect image and forces it into some other refresh frequency.

[MoonDragn]

I managed to get it working with this:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Has relatively no lag and the picture is pretty good.

Why am I using this? because I don't want to set up the amiga 1200 in front of the TV and the only monitors I have are the Asus ROG swift g-sync monitors and my Cforce touchscreen.

The g-sync monitors only take Displayport and the cforce only takes usb-c.

I managed to get an adapter from hdmi to usb-c but the cforce only accepts 1080p and some other computer resolutions.

The orei upscaler converts the OSSC to HDMI which my adapter then converts to USB-C. I know it sounds convoluted but that is what I got. There was no guarantee that buying another portable monitor could solve my problem with the ossc and I have limited desk space where the Amiga 1200 is sitting.