Hi.
I am looking for shaders that simulate monitors compatible with the standards supported by PURE: Hercules, CGA (PCjr - Tandy), EGA, VGA and SVGA. And maybe some real image overlays, or reference images, if they exist.
Muchas gracias. Have a nice day.
Scanline Classic has presets for VGA and higher resolutions. I recommend either vga.slangp, svga.slangp, or xga2.slangp for VGA games. The higher resolutions have a stronger scanline effect.
For Hercules youâll need one of the many monochrome presets which I havenât finished yet. However you will find an example monochrome preset in the demo folder labeled âTheMatrix.slangpâ. You can also use bwtv but that wouldnât be period accurate.
For EGA you can use any of the NTSC presets or a VGA preset as VGA was compatible with EGA and RGB CGA.
For CGA composite youâll need to use an NTSC preset with the appropriate composite emulation. I think DOSBox supports this in the emulator so you wouldnât need to add an NTSC modulation shader but Iâm not sure.
Note that VGA is only compatible with EGA and RGB CGA (NOT composite). EGA was compatible with CGA. Hercules wasnât compatible with any of these (it was for monochrome, business monitors). You wonât find a shader that can accurately simulate all of them at once.
They are fantastic, it would be interesting to have it in Retroarch because of the huge amount of games that PURE has. If I noticed them a little slow, and it seems to me that the vga and xga were getting slower and slower.
Yes, VGA is compatible with EGA, but the idea is to show how the monitor looked like, at that time, and as PURE supports them, well, it would be something like that. I seem to remember that EGA was more blurred and washed out than VGA. It was like comparing Hercules with MDA, and the VGA mask was Slot. Plus the old monitors flickered a lot.
I didnât get anything from EGAâs NTSC in PURE, but I did notice that the Hercules graphics can select between B&W, green and amber, TheMatrix shader has amber pre-assigned.
The difference between VGA and EGA/CGA is primarly that VGA runs everything in 31 Khz, which means double-scan thin scanlines for low-res games and higher refresh rate (60 vs 70 hz). Dosbox will automatically do this when you set it to VGA. CGA and EGA just use standard scanlines in 200-line modes, for EGAâs 350px res, they would naturally be thinner.
VGA monitors are typically shadow (dot) mask, but you can also find the other variants. EGA monitors were already pretty sharp (common dot pitch 0.31mm for standard sized crts) but there were also worse ones (dot pitch 0.39mm and above). In TVL speak, this means about ~450 lines upwards.
You can use Guestâs shaders for this, but how effective it can be emulated depends on your host display.
I also like the VT220 shader for DOS stuff. Its scanlines are not nearly as good/accurate as Scanline Classicâs, but the in-room lighting effects/shadows are pretty convincing and the programmatically drawn bezel is nicely yellowed-beige 
Thanks for trying it out. The system requirements are certainly high, and optimization work needs to be done.
If you have time, try basic.slangp. It uses a single pass shader that cuts out a couple features. Iâve been wondering how they compare.
P.S., Iâd also appreciate if you can post screenshots here or in the shader screenshot thread, to see if everything looks right.
You need to set LINE_DOUBLER to 1. Any content that is emulated by Retroarch with less than half the vertical resolution specified in MAX_SCAN_RATE should then be double-scanned.
With a viewport below 1.1, the scanlines become thinner and appear different in thickness.
Maybe this feature is better with integer scale and monitor above 1080.
For some reason neither the vga or svga presets work for me from scanline_classic. I load the shader and i see the shaders loaded in the list, but all i get is a filtered image with no scanlines in DOSBox Pure.
DOSBox Pure, video options SVGA, svga.slangp and set line_doubler to 0.
It is a good option, you get very interesting results, although it is not very faithful to the time.
The monitors of that time were very different from a TV, had its own personality, and the mask was very important.
The memories are not reliable, but I have clear that they were much more, dense? I do not know the technical term, but they looked sharper and the color was more solid.
I canât get good sources on the internet, but some examples I have obtained may serve as a reference.
A good source of CGA is shown in this video from The 8-Bit Guy.
The monitors were tinted.
In this article in Vogon, you can see the Hercules, CGA and VGA mask on an MDA monitor.
One thing I could not get out of my mind was the famous anti-static shields. The last ones were glass, but the first ones were a metal mesh, which I suspect is to blame for 99% of the baby boomer generationâs blindness. This is going to look great in an overlay.
Thanks to you, tonight I test, although the machine is not the most optimal (it is old), I can have references if it is well optimized or as it looks, I load heavy shaders in the middle of the frame, thatâs how Iâm guided.
I think the important thing is that it is light, or if you think, a fast version for low resource systems and a super optimal one. If you need these references, Iâm looking for more.
I like this shader, it has a retro monitor style, and the metacrt too, Iâm trying them all out, I wonder what the future may hold for 3D shaders?
while super-cool, I donât expect the metaCRT concept will take over any time soon just because itâs so demanding and fragile. Itâs a pretty amazing shader, though
Thanks, thatâs a good, natural image. I have only achieved approximations, with design or illustration work.
I for one found this one, lost in the depths of the forum. Classic CRT Collection - Overlay Pack. There are too many, we need a catalog or something with categories so they donât get lost.
Can you take a screenshot?
Unfortunately, DOSBox has its own scaling which can interfere with the shaderâs output. This may be whatâs causing the issue. If you post a screenshot and your DOSBox settings I can take a look at whatâs going on. Whatâs your screen resolution?
Monitor
1920x1080
Core
DOSBox Pure: VGA
RetroArch
Integer Scale ON
Integer Scale Overscale ON
Aspect Ratio 4:3
vga.slangp
Focus 100%
Viewport zoom 1.1
Viewport zoom 0.90
That shader is good, but it is more of a sample, it is not optimized, the 3d models have many polygons and the sphere consumes, it has two diffused illumination focuses plus environment illumination, if it is optimized possibly it will reach an 80% of speed.
If I give you the 3d model, you do that? We can start with a totally flat model, low poly to test.
no, it doesnât use an actual model. each âmodelâ has to be built via a weird mathematical technique called âraymarchingâ. I donât know much about it aside from the concept.
