ao486 Config for a Plain Old CRT TV

[lu_source]

Out of interest, why do you want to disable the analogue?

Because the output to analog on the MiSTer to MY CRT is all garbled. I tried the timings on this thread but they they are either way too low res and makes text hard to read on both thourgh the CRT and HDMI or I experience the same garbled screen. I'm afraid I will cause damage to my CRT by sending an improper signal, which is way I want to disable it just for the ao486 core (Or any other computer core).

[lu_source]

I found another thread that might be relevant here. It seems to call it "underscanning"

what might have worked there was:
"Instead of vga_scaler=1, you can also try vscale_mode=1

vga_scaler=1 gave me big black lines on most resolutions.
with vscale_mode=1 all resolutions seem fine."
viewtopic.php?f=13&t=1448&p=23560&hilit=15hz#p23560

I have linked to this thread on the previous page. With settings from there the scaling itself looks fine on my consumer TV, but image goes into overscan horizontally. Maybe on PVM it can be remedied, hence matsu's good result. Perhaps with better modeline it could work on normal TVs too.

I have not tried vscale mode. I'll see if that works for me. I don't care about the overscan because I'll actually be using the output on the HDMI port. If I can send a proper signal to my CRT and still have a high enough resolution on my HDMI monitor I'll be ok with not disabling the analog port.

[lu_source]

I think I know what my problem is. This thread help me:
viewtopic.php?t=1471

I need to send a 480i signal but the thread above mentioned that the scaler doesnt support 480i. I can get 240p signals to work but they are way too low res to make ao486 usable on my monitor. I'll just unplug the composite cable if I want to use ao486.

[FoxbatStargazer]

Well after actually trying things out on a TV I can offer a little more insight...

So vscale_mode=1 will make your 320x200 dos games look great, even if a bit letterboxed. But its pretty ugly on DOS text, and the reason for that is that it is truly 720x400. So its attempting to downscale 400 tall to 240 or whatever your resolution is, regardless of integer scaling settings, and that's going to be more of a mess than if it would exactly half the resolution at 200.

One way around this is to set vscale_mode=0 and instead use vscale_border. You should add enough border to shrink the vertical area to 200. Here's an example for 720x240 (224p did NOT work for my TV!);

video_mode=720,24,64,88,240,3,10,6,13500
vscale_mode=0
vscale_border=20

Then in the HUD menu set aspect ratio to full and set the scaling type to either narrow or wide HV integer. Also be sure that low-res is "native" and not 4x. (And of course you are using 60hz not adaptive/variable!)

Result is you will get the full width resolution of DOS text, and exactly half its height. Text is still not super pretty but its about the best you can do on a consumer TV. I also get a bit of overscan cutting off a letter or two on the left but not sure how to get around that for DOS prompt. 320x200 DOS games on the other hand should now appear centered with a black border on all sides and be pixel-perfect. (Use interpolation filter "no interpolation")

Now where this would probably cause issues is for any 240p games like Jazz Jackrabbit. You would have to give up vscale_border to make that looks good, which will sacrifice the cleanness of your dos text.

[FoxbatStargazer]

I think I know what my problem is. This thread help me:
viewtopic.php?t=1471

I need to send a 480i signal but the thread above mentioned that the scaler doesnt support 480i. I can get 240p signals to work but they are way too low res to make ao486 usable on my monitor. I'll just unplug the composite cable if I want to use ao486.

This might be extra dumb but there are external downscaler devices that can take 480p to 480i. Although I'm not sure if they would also passthrough 240p for your other cores.

[lu_source]

I think I know what my problem is. This thread help me:
viewtopic.php?t=1471

I need to send a 480i signal but the thread above mentioned that the scaler doesnt support 480i. I can get 240p signals to work but they are way too low res to make ao486 usable on my monitor. I'll just unplug the composite cable if I want to use ao486.

This might be extra dumb but there are external downscaler devices that can take 480p to 480i. Although I'm not sure if they would also passthrough 240p for your other cores.

Thanks for the recommendation, but I want a much simpler setup. I'd rather just unplug the composite cable when using ao486 than buy an extra external device and, like you said, might have issues with the console cores.

[bstar]

For those with 15khz monitors, I finally got ao486 working perfectly on my PVM with this line (suggested earlier in the thread):
video_mode=640,6,56,66,224,14,8,18,1200

It looks absolutely perfect, like it's the proper native resolution (320x200). I also changed the setting to use the native aspect ratio so that the screen isn't stretched slightly vertically (fonts look a bit off when stretched).

[Jegriva]

For those with 15khz monitors, I finally got ao486 working perfectly on my PVM with this line (suggested earlier in the thread):
video_mode=640,6,56,66,224,14,8,18,1200

It looks absolutely perfect, like it's the proper native resolution (320x200). I also changed the setting to use the native aspect ratio so that the screen isn't stretched slightly vertically (fonts look a bit off when stretched).

VGA scaler = 1 ?

[FoxbatStargazer]

Doesn't matter, VGA Scaler is forced on for ao486 unless you use direct_video.

[akeley]

It looks absolutely perfect

Not really, seems you're missing parts on left and right, so it's just how I mentioned earlier above in this thread.

[_javi_]

Is there any setting for outputting to a Sony Trinitron TV CRT, using directvideo (with an hdmi to vga/rgb adapter) ?

I tried many modes listed in this thread, but i only get a shrunk image to 1/3 at the center of the screen. Selecting widescreen makes it garbled and overexpanded out of the borders.

Of course, many other console/computers cores work a charm in this setup.

[akeley]

Selecting widescreen makes it garbled and overexpanded out of the borders.

Even in games? They will be overexpanded (vertically) but shouldn't be garbled. It's not great but at least you can see what could be, if... I guess some games can be also playable, if you're willing to tolerate such overscan. You can check my .ini, I have a similar setup to yours.

If anybody ever solves this, they will have my eternal gratitude - it's my Most Wanted MiSTer feature atm. Games just look much better on a CRT TV than on a VGA monitor (even though it isn't the native display target). I'm pretty sure it's possible, it works when using crtemudriver on a PC.

[_javi_]

Selecting widescreen makes it garbled and overexpanded out of the borders.

Even in games? They will be overexpanded (vertically) but shouldn't be garbled. It's not great but at least you can see what could be, if... I guess some games can be also playable, if you're willing to tolerate such overscan. You can check my .ini, I have a similar setup to yours.

This is what it looks live when expanded..

I'll check your ini. Thanks!

[akeley]

I saw similar glitching as well before, with some other settings.

One thing which you might want to change from my .ini is "composite sync=0". I have "0" because I also use Ultimate SCART Adapter which has its own CSync jumper. But with just a direct cable from the dongle it needs to be "1".

[_javi_]

I managed to get a readable image with this ini settings..

[ao486]
direct_video=1
vscale_mode=0
vscale_border=1
video_mode=640,8,58,78,240,1,3,18,12324

The parameter which fixed the screen was vscale border. Anything above 0 fixes the garbling. (I dont understand the reasoning behind it)

Theres too much overscan to the left. Maybe i can center the image within the tv Service Menu, but that would break my tuned positioning for others cores.

Many games are playable, but the overall experience is suboptimal. It seems this core was not meant to be used this way.

[MiSTer_Kirk]

Many games are playable, but the overall experience is suboptimal. It seems this core was not meant to be used this way.

DOS games were not meant for a 15hz TV, they are VGA games for VGA monitors. These resolutions are more hacks to get a decent-ish image on a TV, but don't expect anything as good as a real VGA monitor.

[thorr]

I have pixel perfect games on my CRT TV. Dos text is not perfect because the resolution is too high, but games are great. Try these settings:
[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, 170, 140,244,240, 2, 0, 22, 29020 ; Best for ao486

[flynnsbit]

run vmode "insert a number from 0-9" at the dos prompt to change video modes for text and the TDL menu. this will make both legible on a CRT/RGB set. I think I use vmode 4 once you find the one you like, edit autoexec.bat and add it before the tdl command.

[thorr]

Thanks! I am running a plain DOS installation right now, but I will definitely check out your games collection which I assume comes with the required utilities to fix the DOS resolution. I think it includes all the games I am interested in and much more.

[akeley]

I have pixel perfect games on my CRT TV. Dos text is not perfect because the resolution is too high, but games are great. Try these settings:

Well blow me down, it does work indeed! Not ideal, since there are some black bars, but the in-game display seems to be scaled properly and that's all that matters. Perhaps even better solution is possible, but that will do me for now. Thanks a million! I might try that vmode trick for DOS later too, I understand it's an external program?

(one thing: setting "Variable" instead of 60Hz in the OSD breaks things and image gets heavily scrambled/jumping - at least on my setup, Direct Video to a Trinitron)

DOS games were not meant for a 15hz TV, they are VGA games for VGA monitors. These resolutions are more hacks to get a decent-ish image on a TV, but don't expect anything as good as a real VGA monitor.

The MiSTer itself is a big hack to get a decent image on HDMI displays, in a way. VGA monitors were meant for productivity first and foremost, where you need a very sharp image. Many games (CGA-VGA era at least), on the other hand, will look much better on a TV set, where they benefit from bigger size, vivid colours and inherent anti-aliasing (thanks to more pronounced shadowmask/aperture and scanlines). It's now also much more convenient to have everything on one display and not have to switch cables/configs.

I still love having the pure-VGA ability, and it works very well with that modded mister file, but ao486 --->CRT TV is a godsend.

[MiSTer_Kirk]

The MiSTer itself is a big hack to get a decent image on HDMI displays, in a way. VGA monitors were meant for productivity first and foremost, where you need a very sharp image. Many games (CGA-VGA era at least), on the other hand, will look much better on a TV set, where they benefit from bigger size, vivid colours and inherent anti-aliasing (thanks to more pronounced shadowmask/aperture and scanlines). It's now also much more convenient to have everything on one display and not have to switch cables/configs.

I suspect, 99.9% of the 486 era DOS gaming was done on VGA monitors, not 15hz consumer CRT TVs.

I still love having the pure-VGA ability, and it works very well with that modded mister file, but ao486 --->CRT TV is a godsend.

It's ok, not perfect. But side-by-side, my Philips 15hz CRT vs my VGA Monitor, the VGA monitor does look much better. Better, clearer text, and a really nice and sharp image. Anything else, such as consoles, and 8-bit computers, the Philips looks much better.

[akeley]

I suspect, 99.9% of the 486 era DOS gaming was done on VGA monitors, not 15hz consumer CRT TVs.

So? It hasn't been done on HDMI panels either, and yet... Huge chunk of "DOS" gaming also comes from machines where TVs were the main displays (and from the RF/Composite era too), see below.

But side-by-side, my Philips 15hz CRT vs my VGA Monitor, the VGA monitor does look much better. Better, clearer text, and a really nice and sharp image. Anything else, such as consoles, and 8-bit computers, the Philips looks much better.

Really? What about a game which was ported to a PC from 8/16 bit machine (or vice versa)? Ooops

This is a subjectivity-zone, (and also similar to the old tired CRT vs LCD thing), so arguing about it is a bit pointless, but to me there is no contest between a (decent) TV and a monitor - even CRT VGA one - when it comes to most games. Especially after spending few hours today comparing the two. Sharper/clearer image might be important when it comes to productivity software and games which rely on a lot of text. Other ones, with more advanced gfx, look naked & raw because of these factors. I actually remember this was one of our main arguments, from the Amiga side, vs PC debates back in the day, one which was only made redundant with the arrival of SVGA (and games such as Wolfenstein, but that's another story). If people liked to see stairway curves, nobody would bother with developing the anti-aliasing tech, which seems quite popular now. Same with colour banding.

In any case, there are quite a few people interested in this functionality, hence the existence of this thread.

[thorr]

I have pixel perfect games on my CRT TV. Dos text is not perfect because the resolution is too high, but games are great. Try these settings:

Well blow me down, it does work indeed! Not ideal, since there are some black bars, but the in-game display seems to be scaled properly and that's all that matters. Perhaps even better solution is possible, but that will do me for now. Thanks a million! I might try that vmode trick for DOS later too, I understand it's an external program?

(one thing: setting "Variable" instead of 60Hz in the OSD breaks things and image gets heavily scrambled/jumping - at least on my setup, Direct Video to a Trinitron)

Great! I am glad it worked for you. The reason for the black bars on the top and bottom is because the vertical resolution of the TV is 240 pixels and the games are 320x200. To achieve pixel perfect games, you will only be using the center 200 pixels. I added as much black bars on the left and right as possible to not cut off the left and right sides with overscan. Since it has a 1280 resolution horizontally, there is plenty of resolution to show all the pixels perfectly.

Back in the day, there was no good way to hook a PC to a TV, so the games were 100% made for monitors. However, now that we have a way to display them, it could be argued either way which way looks better.

Regarding the "Variable" setting, make sure you also set vsync_adjust=1. It is optional for most things but adds some additional compatibility. I needed it turned on in order to get the PC demo Second Reality working all the way through. If you turn off Variable, you may be able to set vsync_adjust=2.

[_javi_]

....
Back in the day, there was no good way to hook a PC to a TV,
....

Back in the day i had the Ati Xpression PC2TV, and i was a pro, gaming on a 29 Trinitron thru S-video

Maybe recreating an ATI Rage card in ao486 would make TV out easier.


..and back to the subject

I have pixel perfect games on my CRT TV. Dos text is not perfect because the resolution is too high, but games are great. Try these settings:
[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, 170, 140,244,240, 2, 0, 22, 29020 ; Best for ao486

Those give me a nice up to down scrolling screen. Maybe these setting work when using the io-board.

I had to set direct_video=1 to stop the scrolling, as i'm using an HDMI to vga adapter (and then RGBs to the TV)

[MiSTer_Kirk]

So? It hasn't been done on HDMI panels either, and yet... Huge chunk of "DOS" gaming also comes from machines where TVs were the main displays (and from the RF/Composite era too), see below.

How many graphics cards from the 486 era had composite out ? Not many that I can think of. Connecting a consumer-grade TV to a PC, in the early 90s, wouldn't have been a straight-forward thing.

Really? What about a game which was ported to a PC from 8/16 bit machine (or vice versa)? Ooops

Oooops ? The 486 era didn't have many ports from the 8-bit or 16-bit machines - I mean, why would it ? The PC was the dominant gaming machine in the 90s, so any ports would have went from PC to lesser machines.

This is a subjectivity-zone,

Is it ? So a 640x480 DOS game, according to you, looks better on a consumer-grade TV, rather than the display it was meant for ?
Don't be silly. Try a point 'n click adventure, a game where you would need to see detailed graphics AND text. On a TV, these look awful, on a VGA monitor they look how they're supposed to look. And the higher you push the resolution, the better these old adventures look.
Even FPS games, like Doom, look utter shite on a regular TV. On a CRT VGA/SVGA monitor, Doom looks amazing, as does Duke Nukem 3D, and all the other DOS FPS games.

In any case, there are quite a few people interested in this functionality, hence the existence of this thread.

I agree. But not long after trying some of my own ini files, I hooked up my VGA monitor, despite it having an arching issue, I was surprised at how much better DOS games looked compared to my Philips, or Sony TV.

Back in the day i had the Ati Xpression PC2TV, and i was a pro, gaming on a 29 Trinitron thru S-video

Maybe recreating an ATI Rage card in ao486 would make TV out easier.

Both of those cards didn't exist during the 486 days, so not sure what "Back in the day" you are referring to.

[thorr]

....
Back in the day, there was no good way to hook a PC to a TV,
....

Back in the day i had the Ati Xpression PC2TV, and i was a pro, gaming on a 29 Trinitron thru S-video

Maybe recreating an ATI Rage card in ao486 would make TV out easier.


..and back to the subject

I have pixel perfect games on my CRT TV. Dos text is not perfect because the resolution is too high, but games are great. Try these settings:
[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, 170, 140,244,240, 2, 0, 22, 29020 ; Best for ao486

Those give me a nice up to down scrolling screen. Maybe these setting work when using the io-board.

I had to set direct_video=1 to stop the scrolling, as i'm using an HDMI to vga adapter (and then RGBs to the TV)

There may have been TV output cards back in the day, but they were not the norm and companies didn't program for them.
I am not using an IO board. I am using HDMI with an external HDMI to component converter. It's quite possible your HDMI to VGA adapter doesn't like the signal. I had to go through a lot of HDMI to component converters before I found one that works very well. The others would have scrolling issues and other problems.

[FoxbatStargazer]

run vmode "insert a number from 0-9" at the dos prompt to change video modes for text and the TDL menu. this will make both legible on a CRT/RGB set. I think I use vmode 4 once you find the one you like, edit autoexec.bat and add it before the tdl command.

Is vmode.exe not included in your top 300 mister pack?

[akeley]

Back in the day, there was no good way to hook a PC to a TV, so the games were 100% made for monitors. However, now that we have a way to display them, it could be argued either way which way looks better.

Back in the Eighties gaming was low-priority for PC users and most of the significant games from that time are ports from micros, consoles, and arcades. So, made for TVs, so to speak. Even if we allow that games might've been designed on monitors (not always thou) it's obvious, and well documented, that they aimed to utilise the TVs' strenghts, because that was what vast majority of gamers was using. It's also common sense to try and portray reality as it really is - ie vibrant and curved - and not in a blocky, dull way. The PC didn't have any way to remedy that in the pre-SVGA, pre-AA, pre-shader era, so the users just had to live with it.

Great! I am glad it worked for you. The reason for the black bars on the top and bottom is because the vertical resolution of the TV is 240 pixels and the games are 320x200. To achieve pixel perfect games, you will only be using the center 200 pixels. I added as much black bars on the left and right as possible to not cut off the left and right sides with overscan. Since it has a 1280 resolution horizontally, there is plenty of resolution to show all the pixels perfectly.

Again, huge thanks for making this possible. I had a stab at making an appropriate modeline some time ago, but my math-fu is just too weak. It's something I always wanted, especially for the past-1991 games (before that Amiga was still better). And while it;s possible on my crtemudriver PC, it's also very cumbersome to faff around with modelines and Win10@320x200

I get the necessity for black bars, though I also wonder why the bloomin' consoles get to fill the screen while being mostly 224x? Is it an NTSC thing? Anyway, it's not really botehring me. In fact, I think this scaling might even look a bit better than on my VGA monitor, ie: the circles are more round.
getting DOS sorted would be nice though, I need to try tha vmode thing flynnsbit mentioned.

Also, I'll try the vsync_adjust again, I did copypaste your settings but might've left the old one still at "2".

[akeley]

@Mister_kirk: I see expletives, so I guess you're ranting now. Like I said I don't want to derail this thread further, so I'll just do a few bullet points and then you're welcome to carry on. I'd rather concentarte on what this thread was meant to be about: technical stuff about displaying ao486 on CRT TVs.

-instead of talking about some vague "486 era" I prefer "DOS gaming". This applied to MiSTer is probably best described as 1981-early Nineties. Later on ao486 just won't cut it, unless you like to watch slideshows. In that era PC was hardly a "dominant gaming machine" (if ever) and had countless ports from other platforms.

-it's not that relevant anyway, for the reasons I've already mentioned few times ITT and why 240p content looks better on TVs. To visualise it, it here's how Mona Lisa could've looked if Leonardo followed the "clean/sharp" logic.

-Of course you realise that most of DOS's "640x480" is just upscaled 320x200 and 320x240, right? For the proper hi-res games the situation changes, but then I've already mentioned it too, you just chose to ignore it.

-go have a look at any point'n click adventure, observe the text-to-gfx ratio and then tell me how I'm silly again. Alternatively, fire up a modern AAA 3D game, go into settings and switch off all the post process options and the AA. This is what you're arguing for mate

[thorr]

It's possible to fill the screen with pixel perfect 320x200 games without black bars, but it will chop off the top and bottom in DOS (edit: no DOS would be fine because it has 400 for the vertical resolution, but other games would be chopped off like 320x240 or 640x480). I remember seeing a special method for VGA CRT's where the scaler changes resolutions on the fly. This might be worth looking into for this situation as well. I will keep it in mind and try to find time to work on it at some point. I haven't really looked at it, so I don't know if that is an unofficial core that makes the on the fly scaler changes possible.