ViTi95 wrote on 2022-07-26, 21:18:

New game that supports Hercules video card. Super Mario 64.

https://youtu.be/4qXImwCfZco

Beautiful. I love it when new and old come together like this. 💙
Thanks for sharing! 🙂

ViTi95 wrote on 2022-07-26, 21:18:

New game that supports Hercules video card. Super Mario 64.

https://youtu.be/4qXImwCfZco

Lovely, but does it run on anything I'm reasonably likely to think a mono herc card is appropriate for? i.e. nothing much faster than a 286-16?

Edit: ohhkay, seeming like you want coppermine P3 sort of ooomph to play it software rendered at 320x200

ISA VGA cards can do Hercules in emulation mode, too. 😀

So, Athlon XP 2600+ can do Bayer dithering in real-time...

A fast 486 / Pentium can do Bayer dithering in realtime if the code is optimized enough, for example FastDoom runs very well on Hercules.

Akuma wrote on 2021-10-31, 18:39:

Akuma wrote on 2021-10-03, 10:01:

** EXPECT BUGS** and **USE AT OWN RISK** apply here, it has only tested in DOSBox. I still don't have a proper name, I just name […]
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** EXPECT BUGS** and **USE AT OWN RISK** apply here, it has only tested in DOSBox.
I still don't have a proper name, I just named it CGA.COM because it was short 😉

This is the first version of the emulator pack with menu, simple navigation and an INI file to edit. I need help making the INI sane, its just a bunch of options thrown in now.

Everything has been packed into one ZIP file, just unpack somewhere in your PATH and it'll find its way.

No complaints, no feedback. Is anyone using this?

And I forgot to mention, that you can start a game with CGA MYGAME.EXE. Some of the emulators mess up the display and I hate typing in the dark 😉 Alone....again.

Thank you so much for this clean archive! It made it possible for me to systematically test through all the CGA emulators to then - by chance - find a COMBINATION of two of them support Digger Remastered on my family's XT clone fresh from the attic.

For reference, the combination is: ymencga.10 + hgcibm.202

Our XT clone seems to have a particularly bad and unheard of BIOS ("ATEC turbo board version 2.0 1985") and / or Hercules implementation and Digger Remastered is rather challenging for the old machine. Other games do run with several of the CGA emulators solo so this probably is an edge case.

While I wasn't actually running your cga.com, the cga.ini was very helpful to get head starts for the various CGA emulators. Any documentation on these is very welcome and rare to come by.

I'd like to point out there's also versions 1 ("mg.com") and 2 ("mg2.com") of Multi-Graph from Veith System GmbH you could include. It was a commercial product but the author is still around and could be contacted about his stance on copyright (see http://www.independent-software.com/how-did-h … ators-work.html for a review and a comment from the author).

Did anyone able to start Star Trek 25th anniversary , in tandy (display) mode? on my 80286 w/ cga it hangs.....

In case you didn't catch it, CGA plus XT mod for Wolfenstein3D WolfensteinCGA yes it plays at good speeds on period hardware, maybe hurtin' on a PC Jr but turbo XTs run it great. Didn't try it with a CGA emulator yet, but the standard modes are shaded okay on my mono LCD screen.

Hey folks, sorry for resurrecting this old topic, but I need some help. I have written an article on various graphics cards, including Hercules for a certain retro mag in my home country. The trouble is, I can't get proper screenshots from Hercules and they seem to use the ones from the internet, which are plain wrong.

If you check this post in particular from this thread, you will note that screenshots of Hercules games from DosBox look different than their actual on-screen look. And for some reason or other, it is impossible to find the good screenshot from Prince of Persia. So the magazine wants to use this photo: https://www.mobygames.com/game/196/prince-of- … ots/dos/862076/ But it doesn't look like what you would see on the actual screen and it bugs the hell of my OCD. I know this screenshot could be done well using 86Box , but I have just spent an hour trying to set it up properly and failed time and time again. Perhaps I am just a moron.

So I would be very grateful if someone could either:

• send me a screenshot from the same place like the one above (link repeated here) in Hercules amber, ideally via private message and not publicly
• or provide me a link to preconfigured x86Box via private message (once again, not publically, please)

I hope that is all right with you - and sorry for the trouble!

You are supposed to use the monitor's hardwired vertical stretch knob to scale the game to the correct aspect ratio. I can get you a better photo if you want; I just happened to already have this one.

nice sharp hercules...I love it!

copper wrote on 2023-10-13, 16:20:

You are supposed to use the monitor's hardwired vertical stretch knob to scale the game to the correct aspect ratio. I can get you a better photo if you want; I just happened to already have this one.

Hi copper, I was asking more about emulation screenshot, as it is what they usually use. But if you can make a good and stable photo off the screen, then perhaps that would work as well. Would you be able to?

OldCat wrote on 2023-10-14, 13:57:

Hi copper, I was asking more about emulation screenshot, as it is what they usually use. But if you can make a good and stable photo off the screen, then perhaps that would work as well. Would you be able to?

Well in this case, the typical emulator scaling is wrong. Yeah, I can get a photo.

copper wrote on 2023-10-14, 14:29:

Well in this case, the typical emulator scaling is wrong. Yeah, I can get a photo.

In this single particular case yes, the aspect ratio of the Hercules graphics is different than the aspect ratio of the 320x200 CGA/EGA/VGA graphics on a CGA/EGA/VGA monitor. That's because the authors of Prince of Persia did a really low-effort Hercules port (understandably; this was a late 80s game, so it was just a means to milk some easy extra revenue from the game).

From the raw capture it can be seen that they simply re-used the dithered-down 320x200 assets for Hercules mode (measure the extents of the graphics minus the black bars in some drawing program; it's 640x200):

Which looks like this with the correct Hercules aspect ratio (720x348 stretched to a 4:3 monitor). Also remember, the original IBM 5151 did not have stretch controls—that's something that clone monochrome monitors introduced later.

Other games interestingly use a larger than 320x200 "active area" for the graphics. For example, Total Eclipse uses a 640x260 area in Hercules mode. So to stretch both PoP and TE to fill a 4:3 monitor, we'd need two different custom stretch ratios. Moreover, the emulator cannot decide what stretch ratio to use; the best we can do is to use the "canonical" IBM 5151 stretch ratio.

Then we have a large number of games that fully support the 720x348 Hercules mode. The graphics in these games make full use of the total drawable area.

The conclusion from all this is: the IBM 5151 emulation of DOSBox is pretty much perfect with aspect ratio correction enabled. For games that re-used CGA/EGA/VGA assets and thus look squashed on Hercules, the only practical way would be to emulated "OSD controls" so users can set up their custom stretch ratios per game—the emulator doesn't have the information to make that choice.

Hey Rincewind42,
First of all, kudos for the nickname - I'm a huge Terry Pratchett fan myself - and thanks for taking time to contribute to this thread, both in writing and by providing screenshots - much appreciated!

Secondly, you are correct in everything around aspect ratio and lazy port(s) on Hercules.

Thirdly, you are, however, not entirely correct when it comes to the conclusion that "(the IBM 5151) emulation of DOSBox is pretty much perfect with aspect ratio correction enabled" (or partially correct, which boils down to the same result). The error lies in this assumption: "From the raw capture", namely treating both the original machine and the emulated one as a black box with a video output. Yes, if you performed the raw capture of output signal from the actual hardware, it would be very similar to the screenshot(s) you presented, give or take the general imprecision of analogue signal. Yet what you would ultimately see on the screen of amber monitor of that era would look different, due to many factors, but especially the atenuation of the phosphorus. The actual points would not be so sharp (think small normal distribution rather than a singular peak in place of each pixel), but "bleed" a little bit around it, therefore blending the pixels with their neighbours.

Below you can see your screenshot (slightly adjusted for size and aspect ratio) compared with another one (taken from here) that applies this effect:

As someone with access to the original hardware, I can confirm that what you see on the amber monitor from that era with actual Hercules graphics card looks like the second image. This is what I wrote about in this thread before - 86Box seems to emulate this effect rather nicely, but DosBox does not (click the link, please - there are screenshots there and off-screen photo). Therefore DosBox screenshots from Hercules games that are used in various places over the internet and in retro magazines give these titles a different look than the original.

Now, coming back to my original request, which remains unanswered: I cannot seem to force 86Box to work and I don't want to use DosBox screenshots due to the reason stated above. Could someone provide a screenshot from 86Box or a very clear and stable photo off the screen that could be used in print (ideally, via private message)?

A real Hercules monitor certainly shouldn't blend to the same degree that the 86box patch does, at least not if it's in good repair.

In the Gobliiins post, the second image ('with patch') has absolutely solid colors, but the photo off the monitor shows very clear vertical pinstripes.

If you don't mind cooking your shots a bit, you can try this. Using a raw DOSBox screenshot (*not* like the first one in the Gobliiins example -- that one doesn't look like anything other than a bad jpeg-to-png conversion) it can approximate the monitor photo rather well, IMO:

Thank you very much, your input is indeed spot-on! As for your tool, I have bumped into it quite some time ago and watched various retro flavours with awe. You even got plasma right!

Now, the real question is how difficult is it to use? Also, FFMPEG suggests to me application for movies, not still images?

EDIT: Or perhaps, if you excuse my terrible laziness / technical ineptitude, you would be able to convert yhis screenshot https://www.mobygames.com/game/196/prince-of- … ots/dos/862076/ using your tool?

Sure, NP. The Moby screenshot already has interpolation applied, so it's not a good input, but I just took a new one in DOSBox. This one doesn't have the curvature/vignette effects, which might be obtrusive.

Yeah, ffmpeg is primarily for video, but it can do most of the same things just as well for still images, so the script supports those too.

If you want to play with it yourself (and you're on Windows), all you really need is to have ffmpeg's 'bin' folder in the system PATH. Then just put ffcrt somewhere, and in the same directory run "ffcrt <config_file> <input_file>" (the input should be a raw unscaled PNG).

The download should have a few sample config files, which include comments to explain the settings... hopefully they're at least somewhat clear, but for reference, here's the config file I used for this image:

Thanks for the feedback @OldCat and @VileR.

For the record, the Hercules CRT shaded examples I posted were created using the adaptive CRT shaders that will be part of the upcoming DOSBox Staging release. Basically, it will be a set-and-forget solution to get authentic CRT-shaded output across *all* supported graphics adapters, from Hercules to SVGA (authentic in *feel*, so no pixel-peeping please 😄).

I don't have a Hercules monitor, just SVGA monitors (9 of them, to be exact 😎), so I had to rely on photos and videos I found online to dial in the Hercules presets. Still, I have a pretty good understanding of the various CRT monitor technologies and the tradeoffs involved, so here's my understanding and perspective:

- Monochome Hercules monitors were optimised for text, full stop. They were designed for business use, so staring at spreadsheets all day from up close, etc., which means sharpness trumped everything else.
- However, all CRTs have *some* bloom as you increase the brightness & contrast, however minimal. Depending on the particular monochrome monitor, you could get more or less bloom at high brightness settings.
- I actually could get some pleasant bloom by increasing the brightness substantially in my shader, but I don't find the increased brightness pleasant to look at. Well, at least I'm sensitive to overly bright light 😀

My late 90s/early 2000s SVGA monitors don't bloom too much (it's there, but it's very subtle). On TVs, blooming can be extreme—I have a small TV I use for my C64, and on max contrast the white pixels are about 3x as large as the dark gray ones! They become basically big round blobs of light, very cool. But when dialing the contrast back to 40-50%, they're only about 1.5x larger and appear more "rectangular".

Anyway, here's my CRT-shaded output on the left, and VileR's example on the right:

Sure, there's more bloom in the right example (and it's great, btw), but for me personally that's way too bright. Probably I'd prefer something in-between as a set-and-forget sweet-spot setting. Ultimately, I wanna pick something that most people will enjoy, is representative of the "Hercules gaming experience" on a real CRT, and isn't fatiguing to look at for hours (I love your work overall, VileR, don't get me wrong 😎).

The Goblins example is more to my liking, maybe I'll try to mimic the blending on that one a bit more. Ultimately, I'm interested to hear the perspective of actual monochrome monitor owners. If you could post photos of the same image that features dither patterns at *different* brightness / contrast settings, that would be the best! The real solution would be adjustable brightness & contrast controls in the emulation (which will happen one day), so everybody can just dial in the bloom/brightness tradeoff according to their taste. Until then, I just need some good fixed setting that represents "Hercules gaming" well overall.

Here are some of the many photos of actual Hercules displays I used as reference. Note that most of these are tack sharp and have no blooming and blending whatsoever. I assume that's because they were on "business settings", so low to medium brightness & contrast. By increasing the brightness, they would all bloom a bit. However, on the last amber image you can notice a small amount of blending.

It should be noted that in text mode Hercules supports 3 shades: BLACK, NORMAL, BRIGHT.
However, with both BRIGHTNESS and CONTRAST knobs set to max, NORMAL and BRIGHT look the same, therefore my preferred setting for text is: one knob to the max, the other in the middle.

In graphics mode, there's only BLACK and NORMAL.
So, I often set both knobs to the max for graphics.

Overall, there's no single universal BRIGHTNESS/CONTRAST setting, and no single universal amount of blooming.