Screen mode with AGA only

[udihow]

I'm sorry for bringing up this, but there's just so much out there I can't really find exactly what I'm looking for. Or perhaps I'm using the wrong search terms.

Basically, I'm just looking for an answer to what the "best" screen mode is, that I can use with a regular AGA chipset, without any expansions. Fully usable, with 256 colors.

I have realized that there's a lot to this, with all these Hz and KHz-numbers.

Of what I can gather, some of the possible but not listed modes are 640x480, 800x600, 1024x768, 1280x720, 1280x1024 etc.

I have a Dell 20" monitor, with a max support of 1600x1200, connected with VGA/DSUB. Therefore I decided that 800x600 would probably be ok (50% of the native).

So, I installed HighGFX40_6 and HighGFXnmore which both provided 800x600 modes, and some others. However I haven't been able to try that. Anything else than the standard PAL:x and NTSC:x modes give me a black screen.

Also for information, the PAL/NTSC Super high-res gives a compressed unusable image. Not sure why.

Can I somehow figure out what modes and numbers I need, to get 800x600 with my setup?

[Jope]

The 22kHz horizontal refresh is most likely the problem here. Most monitors don't have much support for horizontal frequences above 14 and below 30, even if they can show the 15kHz PAL/NTSC modes.

[udihow]

Just found the specs for the monitor, does it say anything useful?

I noticed that when using the pal high-res, the monitor thinks it receives 800x600?

[Daedalus]

The official specs don't always list everything the monitor can display - many 15kHz-capable monitors only list 31kHz in their specs.

Resolutions like 800x600 from AGA need a trade-off in some other parameter of the signal - as Jope points out, the resulting frequency probably falls awkwardly between what's supported and what's not. I would try the DblPAL and DblNTSC modes, with VGAOnly installed too. These tend to work on many 31kHz monitors as they're close enough to 31kHz to be accepted, though they fall short of the 800x600 you're looking for. Whether they can be scaled to look "good enough" is up to you - the maximum overscan of DblNTSC is something like 720x480, which is fairly close to the proportions of a 16:10 panel.

[udihow]

Not going to use a wide screen monitor for this, 4:3 fits an amiga better, in my opinion at least. However, for testing, I just tried 2 much newer 16:9 monitors. They behave exactly the same, black screen when trying anything else than NTSC/PAL. Except, they report every working resolution as 720x576, even when showing the unusable super high-res mode. Feels like a software problem.

I tried to install something called DblPAL (found on aminet) but it didn't show up as a new screen mode, it just reduced the width of the current PAL mode (to 690, vs 708), So I deleted it.

SUPERPLUS 800x600 shows up as 48Hz, 15kHz while all working modes shows 50Hz, 15kHz. Not much difference, yet it doesn't work.

I guess I have to continue as it is and forget about other screen modes.

[khph_re]

It also depends on what what connector you are plugged into.

I have a monitor with composite that only accepts PAL/NTSC
But through VGA it will only take Double PAL/NTSC

So I have my A1200 hooked up to both, and luckily it auto switches.

[udihow]

On the back of the amiga there's only one connector that the VGA-cable fits in. For normal use I haven't had any problems with video or signal, it's just now when trying to go outside the borders a bit.

There's however 2 other connectors, one unlabeled to the left and one underneath, labeled VIDEO. Could I get a different or better signal out of these?

The monitor does have composite and s-video inputs, but I don't think it would be any better than VGA.

[Jope]

Seems you have an impact vision in your video slot. This card has a built in flicker fixer, which probably will not fare very well with HighGFX and other tweaked monitor drivers. The drivers delivered with the OS might work mostly.

If you wish to experiment more with custom Amiga monitor drivers, I guess a D23 -> DE15 buffered adapter would be a good buy so you can bypass the flicker fixer.

DblPAL and DblNTSC shouldn't need a trip to Aminet, the monitor drivers for should be in storage/monitors. You can just double click them there, then go to screenmode prefs or overscan prefs to try them out. If you end up finding something that works with your setup, then you can move that driver to devs:monitors and it will be available automatically when you boot up the Amiga.

The drivers can have their frequencies boosted by also enabling the VGAOnly driver. To enable it, it has to be in devs/monitors and you must reboot the Amiga, as it is only possible to enable it during startup before the other drivers.

[udihow]

Originally Posted by Jope

Seems you have an impact vision in your video slot. This card has a built in flicker fixer, which probably will not fare very well with HighGFX and other tweaked monitor drivers. The drivers delivered with the OS might work mostly.

If you wish to experiment more with custom Amiga monitor drivers, I guess a D23 -> DE15 buffered adapter would be a good buy so you can bypass the flicker fixer.

Ok, perhaps that is why the output stays at 720x576.

I had a hard time finding anything called D23 to DE15 until I found out that you probably meant DB23. I have something like that, see attached photos, is that it? It fits in the VIDEO connector, but when I connect my monitor to this I get "Out of range" right at bootup, so it is apparently of no use.

Originally Posted by Jope

DblPAL and DblNTSC shouldn't need a trip to Aminet, the monitor drivers for should be in storage/monitors. You can just double click them there, then go to screenmode prefs or overscan prefs to try them out. If you end up finding something that works with your setup, then you can move that driver to devs:monitors and it will be available automatically when you boot up the Amiga.

The drivers can have their frequencies boosted by also enabling the VGAOnly driver. To enable it, it has to be in devs/monitors and you must reboot the Amiga, as it is only possible to enable it during startup before the other drivers.

Thanks, didn't think about looking in there. I tried DblPAL and Euro72, but neither seem to offer anything more than 640px wide. Some of the DblPal modes work, but the picture is blurry and washed out.

[Jpor]

Originally Posted by udihow

I'm sorry for bringing up this, but there's just so much out there I can't really find exactly what I'm looking for. Or perhaps I'm using the wrong search terms.

Basically, I'm just looking for an answer to what the "best" screen mode is, that I can use with a regular AGA chipset, without any expansions. Fully usable, with 256 colors.

I have realized that there's a lot to this, with all these Hz and KHz-numbers.

Of what I can gather, some of the possible but not listed modes are 640x480, 800x600, 1024x768, 1280x720, 1280x1024 etc.

I have a Dell 20" monitor, with a max support of 1600x1200, connected with VGA/DSUB. Therefore I decided that 800x600 would probably be ok (50% of the native).

So, I installed HighGFX40_6 and HighGFXnmore which both provided 800x600 modes, and some others. However I haven't been able to try that. Anything else than the standard PAL:x and NTSC:x modes give me a black screen.

Also for information, the PAL/NTSC Super high-res gives a compressed unusable image. Not sure why.

Can I somehow figure out what modes and numbers I need, to get 800x600 with my setup?

I’m addressing the elephant in the room. If you are planning on high resolution best colour scheme possible. This will impact your Chip RAM. So I’m guessing your aim here is just to have the prettiest Workbench screen with the chipset given but not bothered how this may impact programs with lack of Chip RAM?

[Lord Aga]

Also, a mandatory Dell warning. Although Dells will display 15KHz / 50 Hz picture, and they have analogue inputs, they do some kind of internal 50HZ>60Hz (60>50?) conversion which results in choppy/blurry performance. You will never get a nice picture out of that Dell without some extra hardware.

You are much better off with buying a true 50Hz monitor like tried and true BenQ BL912. Or a TV set.

[Jope]

Originally Posted by udihow

I had a hard time finding anything called D23 to DE15 until I found out that you probably meant DB23.

The 23 pin connector is not quite B width at its shell, so that's why I left the B out. Perhaps I should have said Amiga buffered VGA adapter, which would have given useful google hits. :-)

I have something like that, see attached photos, is that it? It fits in the VIDEO connector, but when I connect my monitor to this I get "Out of range" right at bootup, so it is apparently of no use.

Unfortunately your monitor does not like to sync down to 15kHz, so as you said the sync dongle is not immediately useful. Hang on to it in any case, you might end up with a 15kHz capable monitor in the future.

DblPAL is basically doing the same thing as the Impact Vision's flickerfixer but with the added expense of eating lots of DMA time and slowing down your Amiga. The IV card's flickerfixer is probably the way you would want to go in this case.

Thanks, didn't think about looking in there. I tried DblPAL and Euro72, but neither seem to offer anything more than 640px wide. Some of the DblPal modes work, but the picture is blurry and washed out.

Seems your monitor does not like the Amiga's output very much. :-(

In search of the perfect image you are looking at some level of compromise and/or spending hundreds of euro on this quest. The best results with regards to sharpness can be had by using a digital output using a D520, ZZ9000, OSSC or Indivision mk2/mk3, but all have some caveats. Getting 1:1 pixel mapping to your panel's native resolution is probably only possible with the Indi mk3, most of the others will output a smaller resolution and your monitor's scaler will either do well or not so well when zooming it to fill the panel.

From the above list, the ZZ9000 is also an RTG card, so you can get Workbench in the monitor's native resolution over the digital output, but Amiga custom chip modes will show up in a smaller resolution and again the monitor gets to scale it as it best can.

[udihow]

Originally Posted by Jpor

I’m addressing the elephant in the room. If you are planning on high resolution best colour scheme possible. This will impact your Chip RAM. So I’m guessing your aim here is just to have the prettiest Workbench screen with the chipset given but not bothered how this may impact programs with lack of Chip RAM?

Do applications still use chip ram when there's other ram available?
I usually have about 1.6mb free when running 708x548. Bumping it up to 800x600 is not that much of a difference in pixels at least.

Originally Posted by Lord Aga

Also, a mandatory Dell warning. Although Dells will display 15KHz / 50 Hz picture, and they have analogue inputs, they do some kind of internal 50HZ>60Hz (60>50?) conversion which results in choppy/blurry performance. You will never get a nice picture out of that Dell without some extra hardware.

You are much better off with buying a true 50Hz monitor like tried and true BenQ BL912. Or a TV set.

Perhaps the panel needs a 60Hz signal and that is why they do an internal conversion.

However, personally I haven't noticed any artefacts and the overall picture isn't really bad. Not sure if the card does anything to improve the picture?
Is there something I can run to make it more obvious? Just for evaluation.

Originally Posted by Jope

In search of the perfect image you are looking at some level of compromise and/or spending hundreds of euro on this quest. The best results with regards to sharpness can be had by using a digital output using a D520, ZZ9000, OSSC or Indivision mk2/mk3, but all have some caveats. Getting 1:1 pixel mapping to your panel's native resolution is probably only possible with the Indi mk3, most of the others will output a smaller resolution and your monitor's scaler will either do well or not so well when zooming it to fill the panel.

From the above list, the ZZ9000 is also an RTG card, so you can get Workbench in the monitor's native resolution over the digital output, but Amiga custom chip modes will show up in a smaller resolution and again the monitor gets to scale it as it best can.

I feel it is a bit overkill to go and buy expensive hardware when I'm just using the computer like I do. Which is nothing hardcore, just some occasional tinkering. Currently I think it's better to stop fiddling and keep the settings that work.

Thanks for all the answers and ideas.