ao486 Config for a Plain Old CRT TV

[flynnsbit]

Checking if Binary can make TDL not reset for you guys. Have you tried the other lower vmodes? 3,4,5?

In TDL.INI on E:\

Change this line in it to :
set VESA=0h for mode 6

Vmode 3 does nothing. 4 and 5 have 40 column text (huge).
setting VESA=0h in E:\TDL.INI does nothing in TDL (is 0 correct? that seems wrong to me). I also tried 06h.
Thanks for your help!

The huge text is the point on a 15hz 200 line crt. I don't think 6 is the one you want but it is hard to test where I am at so if you can't find a vmode that you like, that also sticks inside of TDL then I can't help any further.
try them all 0 through 9

[thorr]

The huge text is the point on a 15hz 200 line crt. I don't think 6 is the one you want but it is hard to test where I am at so if you can't find a vmode that you like, that also sticks inside of TDL then I can't help any further.
try them all 0 through 9

Thanks. Mode 6 on my CRT is 80 columns but completely pixel perfect and legible. Mode 3 seems to be the standard mode and is not pixel perfect and missing horizontal lines.

I am confused about VESA=0h. Did you mean 6h? Is there a table that translates the vmodes to the equivalent VESA hex code used in TDL.ini? Is TDL.ini using vmode or something else (can I just say VESA=6)? When you say try them all, do you mean VESA=0h, VESA=1h, etc?

[ash2fpga]

Here are video modes from Ralf Brown's Interrupt List:
http://www.ctyme.com/intr/rb-0069.htm

May or may not be applicable to TDL, though.

[_javi_]

...

[ao486]
; Set it to "Variable" in the ao486 core instead of 60Hz
direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=1 ; Set this to 0 if you want to fill the screen but lose 1 to 1 pixel mapping on 320x200 games
;video_mode=1280,170,140,244,240,2,0,22,29020 ; Old Best for ao486 12-8-2020
;video_mode=1280,138,140,216,240,2,0,22,28070 ; New Best 06-25-2021
video_mode=1280,120,140,202,240,2,0,22,27565 ; New Best Wider 06-25-2021

....

Hope y'all love the new video modes and find this useful.

No matter what modeline i use, i get a rolling screen unless i set direct_video=1.

Maybe the parameters for the ioboard vga output are not the same when using hdmi to vga/rgb adapters.

btw, the more i use exodus/dosbox on my pc (super duper QHD gaming monitor), the more i want ao486 on the sony TV.

[akeley]

That's a great idea about the 50MB vhd file.

Actually, I've just realized MiSTer has shared folder ability. D'oh. If you use flynnsbit's pack it's all already setup: just make a "shared" folder inside fat/games/ao486/ and you can transfer files from PC via ssh. The shared folder is drive Z: in DOS.

[thorr]

No matter what modeline i use, i get a rolling screen unless i set direct_video=1.

Maybe the parameters for the ioboard vga output are not the same when using hdmi to vga/rgb adapters.

btw, the more i use exodus/dosbox on my pc (super duper QHD gaming monitor), the more i want ao486 on the sony TV.

I definitely feel sorry for your situation. The timing parameters are the same, but there are other settings in the ini that might need to be changed. Try adjusting these one at a time to see if it helps:
ypbpr=0 ; set to 1 for YPbPr on VGA output. (I assume you have this set to 1)
composite_sync=0 ; set to 1 for composite sync on HSync signal of VGA output.
fb_terminal=1 ; 1 - enabled (default), 0 - disabled (I am not sure if this makes any difference or not, but I included it anyway)

I am 99% certain you need a different solution than the HDMI to VGA cable you are using. Did you do the sync on green mod to it? The HDMI converter that I am using is no longer made. I ordered a different one from aliexpress.com to test (I don't know how well it works), but the shipment got cancelled for whatever reason so I didn't get a chance to test it. I also found it on alibaba.com but haven't ordered it yet: https://www.alibaba.com/product-detail/ ... 14489.html If you got a VGA IO board, it should work but the color is not quite as good as using the HDMI output. You may or may not be able to tell the difference and be just fine with that solution.

Edit: I just placed an order for the one from alibaba.com. In order to buy just one, you need to click "Buy Samples". It will be several weeks before I get it, but I will report back whether it works or not. Also, you may already have a VGA IO board. I am not sure from your posts. If you do, you can try the timings on that and if they work it will confirm the issue lies with your HDMI to VGA solution. If you didn't do the Sync on Green mod, that would explain why it doesn't work.

[thorr]

That's a great idea about the 50MB vhd file.

Actually, I've just realized MiSTer has shared folder ability. D'oh. If you use flynnsbit's pack it's all already setup: just make a "shared" folder inside fat/games/ao486/ and you can transfer files from PC via ssh. The shared folder is drive Z: in DOS.

That's awesome! Thanks for the information.

[bbond007]

Thanks. Mode 6 on my CRT is 80 columns but completely pixel perfect and legible. Mode 3 seems to be the standard mode and is not pixel perfect and missing horizontal lines.

I believe 0 tells it to not set the video mode.

Anyway,

Mode 6 is a graphics mode - the screen is stored in a bitmap. The BIOS is essentially emulating a character display in graphics.

TDL is designed to run in text mode where the screen is stored as an array of character and attribute data. Text mode works similar to tile maps for game consoles where the character ROM is like the tiles and the video RAM is like the map.

TDL does not use the BIOS for screen writes and manipulates the RAM directly, so this simply won't work...

[thorr]

Thank you very much for the detailed response. That makes sense. I can still use TDL just fine so it is not the end of the world if it is not pixel perfect. At least DOS can be now which is a nice improvement anyway.

[bbond007]

Thank you very much for the detailed response. That makes sense. I can still use TDL just fine so it is not the end of the world if it is not pixel perfect. At least DOS can be now which is a nice improvement anyway.

I tried to make it work with pcem then I realized why it was not working.

Ideally I think you need a GFX mode launcher....

[FoxbatStargazer]

No matter what modeline i use, i get a rolling screen unless i set direct_video=1.

Maybe the parameters for the ioboard vga output are not the same when using hdmi to vga/rgb adapters.

To reiterate, your modeline is irrelevant when using direct video, its just using whatever resolution the core decides on. So yes the direct video resolution settings are different, but you can't control them!

Direct_video seem to pass through some modifications of the analog signal that will not appear from HDMI otherwise. Ypbpr and csync in the ini normally only affect the analog out, that might be passed along HDMI when you use direct video. I'm not so sure about the SoG switch.

I don't know how your "VGA adapter" is connecting to your TV. I'm assuming its HDMI->VGA, and then VGA->?. You might need to find a more fully featured adapter if you ever want to move beyond direct video, or else get a working I/O board (which can use ypbpr/csync in conjunction with vga_scaler)

I will say direct video seems to display 200p DOS games pixel-perfect, just maybe not centered where you will like. 720x400 DOS OTOH will always be slightly ugly (though still readable), though maybe by changing the vmode within DOS you can get around that.

[thorr]

I got a new Sony 20-KVFV300 CRT and spent quite a bit of time on it. I set up the TV service menu geometry to work well with SNES and NES. I tried to find a happy medium vertically for 224p and 239p resolutions. 239p is cropped by about 6-7 lines on the top and bottom, but 224p fills most of the screen with tiny black bars on top and bottom. I wanted to make 224p my primary geometry because most consoles use that. My TV has a couple of horizontal white lines in the upper left corner that I try to move above the screen so they are not displayed, and keep as much of the normal lines visible as possible. If anyone tries my numbers and finds the geometry is slightly off compared to their settings, this may be the reason.

For ao486, here is my video mode for maximizing the vertical screen size for 320x200 games and DOS. There are still black bars on the top and bottom, but they are as small as I can get them and still have it be in sync on the monitor. The left and right side go right to the edge without cutting anything off.
[ao486]
; Set it to "Variable" in the ao486 core instead of 60Hz
direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=3
video_mode=1280,95,140,187,240,11,0,19,27543 ; best for 320x200 and DOS

The above will cut off the top and bottom on 320x240 games like Epic Pinball. I still need to work on settings for this mode.

In the meantime, for the menu, currently I have these settings, but I may tweak them further:
vscale_border=5 ; vscale_border=5 does not work with ao486
video_mode=1280,112,140,178,240,0,0,18,26445

[akeley]

@thorr: did try your latest...work ok, though the difference is not that big compared to other ones. I guess this is pretty much as good as it gets - which is great already. Actually, DOS itself is now squashed and looks kinda 320x200, but that's ok.

I was doing some random comparisons vs games on my PC+VGA CRT and was thinking about AR. Obviously the VGA monitor has 4:3 AR while this method yields a squashed image...a bit like Amiga. I don't suppose there is any chance to produce a 4:3 modeline (or force 320x240?), even if it had some more black bars on the left/right?

I'm just curious really... now, in theory 4:3 should be a standard, but I think in practice not all the games were produced with it in mind (unlike for consoles). Some (most?) DOS games look ok in 4:3, but some do look too stretched (Advanced Destroyer Simulator is a good example, because it has a lot of round dials).

Also, an unrelated thing: I fired up Conan the Cimmerian(1991) and saw that some colours are different - if anybody wants to check, just Restore Game and look at the buildings. In Dosbox on my Windows IPS panel they are white-ish, like marble. Here, both on a CRT TV & VGA (real DOS PC) they look similar to the streets - shade of brown. Why the difference? I know the LCD tech, and Win colour profiles might differ from CRTs, but have never seen such pronounced discrepancy. It's also odd, because you'd've thought the marble one was the intended colour...

[FoxbatStargazer]

The games are 320x200 and you are displaying them on what is likely 240p(244p) display at 60hz. So either you eat some ugly scaling, or you're going to have some black bars on top and bottom. (Or maybe you can really push your vsize TV adjustment?)

The horizontal resolution of CRTs is more arbitrary so we have some choices here. Given you accept black bars on top/bottom to get the vertical resolution right, you have to either stretch games edge to edge (giving that squashed/PAL look), OR you can put black bars on the sides too, to try and get a 4:3ish image in the center. The settings I posted used 720 wide or 1440 wide to get the full 720 DOS text resolution, if you turn on HV Integer scale, then the games will only go to 640 or 1280 wide, leaving black on either side, which will end up not exactly but very close to 4:3. So if you want to try 4:3 look I would recommend those.

To be clear on a real PC monitor you would always see 4:3 and yes, the pixels would be tall. Devs varied on how much they corrected their games with what is essentially 16:10 if you treat as square pixels. Everything in Doom is kind of fat and intended to be squashed together for example. But a more interesting example is duke nukem 2, where the proportions on the large-style intro scene art are very fat and meant to be compressed to 4:3, however the game itself seems to use perfect squares in level design that get squished to tall rectangles on a 4:3 display. 4:3 is how we played it at the time (unless you really wanted to use vertical adjustments to put black bars on top/bottom), but of course its your choice how you want to play the games now.

[akeley]

The games are 320x200 and you are displaying them on what is likely 240p(244p) display at 60hz. So either you eat some ugly scaling, or you're going to have some black bars on top and bottom. (Or maybe you can really push your vsize TV adjustment?)

I've been dealing with this TV maths thing for years, but it somehow still remains black magic for me. My simpleton of a brain just struggles to visualize it. After all, the arcade/console resolutions are also in the 190-240 range, and yet it's possible to fill the screen with them. I know you're obvioulsy correct, it's just...ah, nevermind I guess I'll never "get" it.

Sure, I could stretch it in the service menu, but then it'd mess up everything else, so...

The settings I posted used 720 wide or 1440 wide to get the full 720 DOS text resolution, if you turn on HV Integer scale, then the games will only go to 640 or 1280 wide, leaving black on either side, which will end up not exactly but very close to 4:3. So if you want to try 4:3 look I would recommend those.

I did try these from 2 pages ago, with the "video_mode=1440,40,136,176,240,3,10,6,27000" modeline. When I measured the result with a tape, the ratio was ~1.5 which is indeed better than 1.6 of 320x200. Still, would it be possible to push it even more towards 1.33 (4:3)? The black bars are ok, since on 21" TV the image is still bigger than even on a large PC monitor.

To be clear on a real PC monitor you would always see 4:3 and yes, the pixels would be tall. Devs varied on how much they corrected their games with what is essentially 16:10 if you treat as square pixels.

Yes, it's rather interesting, and overall all the different AR results don't really bother me (the only thing I can't bear is bad scaling). People like me, who also grew up with machines like PAL Amiga got used to all kinds of TV weirdness. Back then we didn't have much choice but now it's nice to be able to experiment with different methods and settings.

[thorr]

Before you said the side borders were too big, and now you want big side borders, lol. If you try my previous settings with the too big borders, they should be closer to 4:3. Getting an even more 4:3 mode should be possible, but personally, I would rather fill the screen than having a huge black border all the way around. If you really want this, I can try when I get a chance.

[akeley]

Before you said the side borders were too big, and now you want big side borders

Of course, that's the beauty of MiSTer + CRTs It's so easy to experiment and tinker. In the RPi+Pi2SCART or crtemudriver world it's more of a struggle and not that fun.

But like I said, I'm happy with what we have already, anything else would be a bonus*. Filling the entire screen would be ideal, but is said to be impossible, so... The 320x200 nearly-wall-to-wall config is great, but a more 4:3-ish one would be nice too.

*cough*...DOS programs...*cough*

[thorr]

a more 4:3-ish one would be nice too.

You're right! Try these... I am quite pleased, but still experimenting. These may be as good as it gets.
[ao486]
; Set it to "Variable" in the ao486 core instead of 60Hz
direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=3
video_mode=1280,159,140,248,240,11,0,19,29568 ; Good for 320x200 games, not 320x240

[thorr]

I did some more tweaking. I think this is my final version. It is extremely close to 4x3 aspect ratio and has the smallest border I could get and keep it at 59.94Hz and stay in sync.
[ao486]
; Set it to "Variable" in the ao486 core instead of 60Hz
direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=3
video_mode=1280,152,140,261,240,15,0,19,30105 ; 4x3 for 320x200 games, 16.42kHz, 59.94Hz

Some TV's may have trouble syncing at 16.42kHz. My settings in the previous post might work if this post doesn't, as they are slightly less aggressive, or you can try reducing the 30105 number, but you will lower the 59.94Hz and might get tearing in games.

(Right click and Open Image in New Tab (in Firefox) and click on it to see the full resolution.)

n4DpnWh.jpeg (1.9 MiB) Viewed 25032 times

VW56HSf.jpeg (1.78 MiB) Viewed 25032 times

vAbSBxJ.jpeg (2.21 MiB) Viewed 25032 times

For your reference and comparison, this is how I set up my CRT geometry with the SNES. This is the Grid at 256x224. I have minimal borders on the top and bottom. The upper right corner is slightly cut off and I need to open the CRT to try to fix that.

fjwZDMW.jpeg (1.67 MiB) Viewed 25032 times

[thorr]

Here are my new timings for the Menu. They provide pixel perfection when running the Update_All script.

[Menu]
direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=1
video_mode=640,65,60,108,224,16,0,26,13919 ; 15.94kHz 59.94 Hz Best 7-8-2021

HcChwgn.jpeg (1.56 MiB) Viewed 25036 times

[hiddenbyleaves]

Really, really cool! Thanks for working this stuff out guys.

[akeley]

16.42 Khz...whoosh! Living dangerously Yeah, my TV said "nope!" to that. Bit odd, as it's one of the newer, very flexible Trinitrons, but what can you do. I think it might something to do with it being from PAL region, even though it's NTSC capable (I also can't change from "60Hz" to "variable" in OSD because it blows things up).
But, it's okay, the other (29568 ) settings are pretty good too, even though bars are bigger. I measured the ratio and it's ~1.42 - not bad!

Interestingly, the DOS is still squashed since the last few days, like in 320x200. Not sure why. It doesn't bother me, but I'm curious why it's different from you and foxbat. I attach my .ini, if you ever find a minute, take a look, maybe you'll see something odd.

[thorr]

16.42 Khz...whoosh! Living dangerously Yeah, my TV said "nope!" to that. Bit odd, as it's one of the newer, very flexible Trinitrons, but what can you do. I think it might something to do with it being from PAL region, even though it's NTSC capable (I also can't change from "60Hz" to "variable" in OSD because it blows things up).
But, it's okay, the other (29568 ) settings are pretty good too, even though bars are bigger. I measured the ratio and it's ~1.42 - not bad!

Interestingly, the DOS is still squashed since the last few days, like in 320x200. Not sure why. It doesn't bother me, but I'm curious why it's different from you and foxbat. I attach my .ini, if you ever find a minute, take a look, maybe you'll see something odd.

I have lots of stuff to say to a short reply.
- For the variable setting, try changing the vsync_adjust setting to other values that have more lag. It might make it work.
- The 29568 works for you? Excellent. I think the ratio can be fixed. I didn't spend time measuring it and getting it exact with that mode. The thing that pushes the limits is getting the vertical as small as possible. Increasing the horizontal margins is most likely doable.
- No need to look at your .ini. The height of DOS is the same as 320x200 video modes. Dos has a 400 vertical resolution so it is double 200. It was previously filling the screen because you didn't have one to one pixel mapping set up. Now that it is pixel perfection in 320x200, it affects the vertical sizing of DOS.

[_javi_]

Every new post and modeline gives me hopes and i try again, only to find the same problem:

Rolling vertical image. (Some modelines scroll slow and others do it fast)

I always get the vertical rolling screen when forcing modelines and turning off direct_video

direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=3
video_mode=1440,40,136,176,240,3,10,6,27000

I get ultra clear picture with that ini, but it scrolls up slowly. What parameters should i fine tune??

PS: Maybe i should note that i'm using an HDMI to VGA adapter. Then VGA to RGBs custom wiring. (Works a charm with other cores)

[akeley]

@thorr:
-if you feel like tweaking it all further, go ahead - I think I'll take a break and play some games finally Guybrush still looks a bit chunky but I think it's cuter this way. And 1.42 is pretty close to 1.33 already...
-re: "variable", I did try adjusting vsync but it's still not working. But then, it doesn't really seem necessary anyway.
-DOS is not really pixel pefect, well, not in the programs at least (but that's where it matters). It'd be nice to have it sorted but one can get used to the warped Dos Navigator look, and there aren't many games which use this mode (some early ones only, I think)

@_javi_: please attach your entire config. You can also try switching composite sync=0/1 when you change direct video.

[_javi_]

@_javi_: please attach your entire config. You can also try switching composite sync=0/1 when you change direct video.

changing composite sync made no difference. Still scrolling

[thorr]

Every new post and modeline gives me hopes and i try again, only to find the same problem:

Rolling vertical image. (Some modelines scroll slow and others do it fast)

I always get the vertical rolling screen when forcing modelines and turning off direct_video

direct_video=0
vga_scaler=1
vsync_adjust=1
vscale_mode=3
video_mode=1440,40,136,176,240,3,10,6,27000

I get ultra clear picture with that ini, but it scrolls up slowly. What parameters should i fine tune??

PS: Maybe i should note that i'm using an HDMI to VGA adapter. Then VGA to RGBs custom wiring. (Works a charm with other cores)

I plugged that mode into the calculator here: https://www.epanorama.net/faq/vga2rgb/calc.html
Both the Horizontal and Vertical are too low. Try changing the last number to 27820. When you plug it into the calculator, you need to use 27.82 in the Pixel clock frequency box. If that doesn't work, try starting at 27100 and increase it 100 at a time and see if you can get the scrolling to stop. Once it is stable, you can move it up, down, left and right with the buttons in the tool above. If it moves it too far left or right, you can see how it affects the numbers 8 at a time and move it 1 or 2 at a time manually by just typing the numbers instead of using the buttons.

[thorr]

@thorr:
-if you feel like tweaking it all further, go ahead - I think I'll take a break and play some games finally Guybrush still looks a bit chunky but I think it's cuter this way. And 1.42 is pretty close to 1.33 already...
-re: "variable", I did try adjusting vsync but it's still not working. But then, it doesn't really seem necessary anyway.
-DOS is not really pixel pefect, well, not in the programs at least (but that's where it matters). It'd be nice to have it sorted but one can get used to the warped Dos Navigator look, and there aren't many games which use this mode (some early ones only, I think)

@_javi_: please attach your entire config. You can also try switching composite sync=0/1 when you change direct video.

I may give it a go just to help you and others out who can benefit, when time permits. I know what you mean about just taking a break and playing games. I am not quite there yet. I am building an arcade cabinet with a rotatable screen and interchangeable control panels and I can't wait to finish it. Then I will stop for awhile and start playing games.

The variable setting affects "Second Reality" and probably other things. If it doesn't affect what you are using, then no need to worry about it.

DOS will never be pixel perfect unless you use Vmode 6 or similar, but this does not work with many text based applications. The resolution is too high and this is a limitation of 240p. Now if we were to get 480i support in the scaler, then we would have the goods.

[akeley]

This 1440 modeline is from Foxbat, it works fine on my TV. But he's missing the other bits:
video_mode=1440,40,136,176,240,3,10,6,27000
direct_video=0
vscale_border=20
vscale_mode=0

@_javi_ : you need to change the other values as well, like above, not just "video_mode". I've looked at your config, apart from that it seems okay, but you can download mine from few posts up and try it too, it won't hurt.

The only other thing I can think of is that your cable might be not up to scratch. When I first started I got a AG6200 based DAC, and a MiSt VGA cable. Most cores worked fine with that, but few caused problems (like Atari ST and ao486 as well) - the image was rolling. I thought it's something in the config or cores, but others have reported them working. Eventually, one day I tried Ultimate SCART Adapter I had lying around and all the problematic cores started working.

So you can look at modifying your cable first, if it doesn't have the 470 ohm resistor, or perhaps consider trying that adapter (there are some similar ones cheaper on ebay) though I can't guarantee it will work. All this is assuming you're using SCART TV, component is probably different kettle of fish.

[thorr]

vscale_mode=0 will kill pixel perfection, but with the vscale_border=20, it probably fixes it. I think vscale_mode=0 allows vscale_border to work, because normally it does not with ao486. I agree the cable is most likely the main issue, but maybe _javi_ can get it to work with at least one mode.

Supposedly these work well and could be combined with a HDMI or vga to scart cable:

https://www.retrotink.com/product-page/rgb2comp