OSSC (Open Source Scan Converter) with an Amiga

[rabidgerry]

Originally Posted by Shaytan

I'm still thinking that the OSSC doesn't like your monitor...

I think you are right, which is a shame.

If I can stomach another bout of OSSC brawling I will try it with my Samsung 913n.

However the NEC has very fast response so I would not want anything less than this that which is 5ms I believe. The Eizo monitor I was looking at to buy which I believe would also be a good candidate for working with the OSSC is 20ms. I dunno what the Samsung is. I will try check it out soon. In the mean time I've hooked the good old GBS-C up.

[Shaytan]

Originally Posted by rabidgerry

I think you are right, which is a shame.

If I can stomach another bout of OSSC brawling I will try it with my Samsung 913n.

However the NEC has very fast response so I would not want anything less than this that which is 5ms I believe. The Eizo monitor I was looking at to buy which I believe would also be a good candidate for working with the OSSC is 20ms. I dunno what the Samsung is. I will try check it out soon. In the mean time I've hooked the good old GBS-C up.

Keep in mind that the OSSC was made for modern 16:9 1080p display, buying a not so recent 4:3 lcd could potentially lead to even more issues.

[rabidgerry]

Originally Posted by Shaytan

Keep in mind that the OSSC was made for modern 16:9 1080p display, buying a not so recent 4:3 lcd could potentially lead to even more issues.

Wouldn't this be pointless though as you will just end up wit stretched displays? I used to use my Amiga with a 32" sharp tv and thought it was great, but thenI realised everything was stretched lol.

I thought lots of people used 5:4 monitors with OSSC. I can use it with mine as well I just can't use the DBLPal driver.

[Jope]

Depends on the screen, many allow you to adjust the aspect ratio.

Unfortunately the older the screen, the less compatible it is with the refresh rates that come out of our old computers and games consoles, but that doesn't automatically any new screen will be compatible either.

The OSSC does not stop the search for a suitable screen, but it does give us more choice when hunting.

[rabidgerry]

I believe the Samsun 913n has a response of 8ms so if it works with the OSSC it might be a keeper. NEC has speakers though which is a bonus.

***edit*** I just checked and the Samsung has a range for Horizontal Synchronization : 30 ~ 81 kHz, may be it's a good candidate in more ways than one for the OSSC. Looks like I will be testing it out later on then.

[MrClump]

Originally Posted by rabidgerry

@MrClump how did you get on? Did you try my settings?

I didn’t have much joy, so I took the monitor to work where it is now doing sterling service rotated into portrait mode for my todo list.

[rabidgerry]

Originally Posted by MrClump

I didn’t have much joy, so I took the monitor to work where it is now doing sterling service rotated into portrait mode for my todo list.

Shame as it's a good monitor.


Tried the Samsung last night and managed to actually get something to display using the DBLpal. But it doesn't fill the screen and I can't get the image any bigger no matter what I do.

Can I get pixel perfect workbench if I use a screen mode that has say 640 horizonal and 600 vertical, but I change the vertical to be 512 instead, then use the DBLpal overscan settings? Would this equate to the same thing or am I tripping?

[Shaytan]

Originally Posted by rabidgerry

Shame as it's a good monitor.


Tried the Samsung last night and managed to actually get something to display using the DBLpal. But it doesn't fill the screen and I can't get the image any bigger no matter what I do.

Can I get pixel perfect workbench if I use a screen mode that has say 640 horizonal and 600 vertical, but I change the vertical to be 512 instead, then use the DBLpal overscan settings? Would this equate to the same thing or am I tripping?

You can try something like SuperPlus which is a modified version of the Super72 monitor driver (800x600) or even go higher with monitors like HighGFX (1024x768) but all of them will probably be interlaced so without a flickerfixer or an Indivision I doubt they are usable if you can get a picture (I don't).

https://aminet.net/package/driver/moni/HighGFXnmore

[rabidgerry]

Originally Posted by Shaytan

You can try something like SuperPlus which is a modified version of the Super72 monitor driver (800x600) or even go higher with monitors like HighGFX (1024x768) but all of them will probably be interlaced so without a flickerfixer or an Indivision I doubt they are usable if you can get a picture (I don't).

https://aminet.net/package/driver/moni/HighGFXnmore

I have all those drivers, in fact I have so many I have lost my mind.

If use something like this for example HighGFX 1024x768 (don't think my monitors like it), I can't use 2x mode right? So what if I modify the size using Overscan and change to 640 x 512, will this work then if it is doubled? I don't really understand overscan, is it a customizable screen tool basically where you can change any drivers output?

I think with my NEC monitor accepted a multiscan mode at one point, can't recall as I have tried so many and spent many hours on this now.

Also if I use the DBLpal driver v45.5 with VGA only I get some crazy output like 98.5khz!! What the hell is going on there?

[Shaytan]

Originally Posted by rabidgerry

I have all those drivers, in fact I have so many I have lost my mind.

If use something like this for example HighGFX 1024x768 (don't think my monitors like it), I can't use 2x mode right? So what if I modify the size using Overscan and change to 640 x 512, will this work then if it is doubled? I don't really understand overscan, is it a customizable screen tool basically where you can change any drivers output?

I think with my NEC monitor accepted a multiscan mode at one point, can't recall as I have tried so many and spent many hours on this now.

Also if I use the DBLpal driver v45.5 with VGA only I get some crazy output like 98.5khz!! What the hell is going on there?

Overscan Prefs can't underscan a resolution, so no, you can't reduce the screen size.
HighGFX, SuperPlus etc are all hacked monitors so I don't think Overscan Prefs would work at all.

Don't know about your frequency using VGAOnly.

[rabidgerry]

Originally Posted by Shaytan

Overscan Prefs can't underscan a resolution, so no, you can't reduce the screen size.
HighGFX, SuperPlus etc are all hacked monitors so I don't think Overscan Prefs would work at all.

Don't know about your frequency using VGAOnly.

I got that wrong it's 93.5hz, so I assume that's refresh rate. No idea why that is. If I use the original DBLPal driver that was in OS3.1 storage and VGAOnly I get like 52.5hz refresh rate. The DBLpal with the crazy read out is from OS.3.1.4 or just v45.5 if you will.

Yeah totally fed up with this, it's been a big let down for this Amiga user anyways.

[danko]

Hi, I would like to buy ossc to connect Amiga to an LCD TV in your opinion is it worth it?

[jbenam]

Lately I finally had a bit of time to hook the A1200 on my usual TV + OSSC and after some fiddling with the settings the result was amazing. Much better than the usual LCD with their horrible upscalers which end up causing moire effect on grids.

One thing to keep in mind is that the OSSC is not plug and play, you have to know what you're doing (even if the Generic modes are already good enough for most gamers, imho) if you want to get the best quality out of it.

[Playaveli]

Originally Posted by jbenam

Lately I finally had a bit of time to hook the A1200 on my usual TV + OSSC and after some fiddling with the settings the result was amazing. Much better than the usual LCD with their horrible upscalers which end up causing moire effect on grids.

One thing to keep in mind is that the OSSC is not plug and play, you have to know what you're doing (even if the Generic modes are already good enough for most gamers, imho) if you want to get the best quality out of it.

Can you share your settings? That would be cool.

[jbenam]

Originally Posted by Playaveli

Can you share your settings? That would be cool.

I have pretty much used the settings from the first post then tweaked the values a bit to see everything as sharp as possible. I will try to take a picture later.

[Playaveli]

Originally Posted by jarp

Hi all!


PAL:HiRes (724x284), PAL:LowRes (362x284):
240p/288p lineX3: Off
H. samplerate: 908
H. synclen: 60
H. active: 724
V. active: 284
H. backporch: 76
V. backporch: 25
Sampling phase: Adjust until you get stable and crisp picture.
Note: If V. active 284 does not work you may try 288 (PAL standard).

Thanks for these settings. Pixel perfection!

[rabidgerry]

Unfortunately I am have decided to give this a go again!

So I bought a different monitor and it can accept Amiga Pal ok.

So now I'm using DBLpal to get a x2 line doubled 1280x1024 output from my OSSC into my monitor.

However I cannot get an image bigger than this. Any ideas? Nothing gets me a bigger image. This is as large as I can make it. It doesn't even show me the full workbench screen, part of which is chopped off at the side.



If I can't get a picture to fill my screen using these settings then I can only conclude my OSSC has been faulty all along!

[Jope]

What's your h.samplerate and h.active?

Unrelated to the dblpal sampling problem:
I didn't quickly see from the past discussion why you're using dblpal + vgaonly .. PAL games will not run in this screen mode so if your monitor won't sync to pal through the ossc, then you'll have a bad time anyway.

[rabidgerry]

Originally Posted by Jope

What's your h.samplerate and h.active?

h.sample rate = 1040
h.active = 640

Originally Posted by Jope

Unrelated to the dblpal sampling problem:
I didn't quickly see from the past discussion why you're using dblpal + vgaonly .. PAL games will not run in this screen mode so if your monitor won't sync to pal through the ossc, then you'll have a bad time anyway.

I'm confused at what you are saying here. So I am lead to believe I can get a pixel perfect display using DBLpal into a 5:4 monitor (its a Viewsonic ViewSonic VA916g this time) that has best resolution at 1280x1024 that is correct right?

My monitor does sync to Pal, I don't remember saying it didn't?

Every time I discuss the OSSC I always seem to get told something different

So to run an OSSC you need a monitor that can accept Amiga PAL which is just below 50hz right? 49.92Hz or there abouts. So both my monitors can accept this.

If you mean that I will need different settings on the OSSC to run games then I know this, and I think what people suggested here before was to have a separate setting I can switch to on the OSSC remote.

However in saying that I have an issue where if DBLpal and other drivers are in the monitor folder in devs it causes some games like F1GP to load all distorted and messed up. As of yet I haven't heard of a solution for this. Again suggested back a while ago someone said disable mode promotion, but this was already disabled for me.

@Jope If you had a 5:4 Monitor then how would you set it up with your Amiga?

[Jope]

You should increase h.active until you see the entire screen. Currently you are taking 1040 samples of the horizontal sweep and showing 640 of them on screen. In an ideal world, your h.sample rate would be very close to the actual amount of "pixels" that the entire horizontal sweep with blanking contains and h.active is the part of the sweep with actual content in it. Armed with this knowledge, it will probably now make sense how the ratio of 640 "active" samples out of a total of 1040 will not result in the entire WB screen showing up. In reality the invisible part of the screen is a lot smaller.

I've been following your OSSC journey with half an eye, but unfortunately I really haven't been paying enough attention to remember what has been told and by whom.

My OSSC recipe: I configure the OSSC so that it shows exactly PAL max overscan (using overscan prefs to stretch to maximum, then I adjust the OSSC in that screen). Then I put up a single pixel alternative dither pattern (wbpattern prefs is useful) and adjust phase so that it snaps into pixel perfection.

And then I use PAL forever after with the OSSC.

Filling the screen and pixel perfection are mutually exclusive, as you have noticed. I try to choose / adjust my monitors so that they are as pixel perfect as possible in a 4:3 aspect ratio. The OSSC outputs a perfect 1:1 pixel digital image with my settings, but after it gets shown on a monitor it gets mangled a bit, as the Amiga's PAL max overscan resolution does not match up with any panel's native resolution or any VESA standard resolution.