Chuck(G)
25k Member
Not taking any issues with the post, but I wonder if a later EGA card might give the same display (some EGAs could do 800x600). That would also be all-digital, right?
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World first(?) all digital VGA video 486 PC
- Thread starter juj
- Start date
Eudimorphodon
Veteran Member
There were VGA cards made by several companies (OAK, ATI, etc.) that had both digital and analog connectors on them. Once out of curiosity I did connect the digital output from an OAK O37 to an old NEC Multisync that accepted both TTL and analog signals and, yeah, it worked. (The digital port was mostly for backwards compatibility with older monitors, you could set a DIP switch to strap the card to only act like EGA, CGA, Hercules, but it did output a 31.5khz signal when the switches were set for VGA.) Palette was obviously a bit messed up, especially in 256 color mode.
(Messed up palettes were also a thing with early TTL laptop LCDs. I still have a 486 mini notebook that has a C&T chipset that only does 12 bit (4 bits-per-color) to the LCD instead of VGA's 18 bit or modern SVGA's 24 bit. It's normally "fine" but the jig is up if you go to a 256 color mode and try to display grayscale images, you only get 16 grays instead of 64; the difference is *very* noticeable. Truly ancient color laptops sometimes had 6 (EGA depth) and 9 bit LCDs.)
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Agent Orange
Veteran Member
Well, I for one am not using my 15" LCD for 320x240 with my 1000SX as it has an Oak VGA and the video is outstanding. The whole purpose of the upgrade was to get rid of MDA/CGA etc which as you stated "sucks".
Eudimorphodon
Veteran Member
The one I had for a while (Pentium 200) had a VGA card with a C&T chipset that could directly drive an LCD panel.
Some of the older ones with mono screens (plasma) did use displays that plugged directly into a feature connector, though I think they still may have used hacked video BIOSes so the 70hz VGA modes were adjusted to run at the 640x480x60hz framing?
Do you maybe mean "when scaling is not integer"? (i.e. an integer multiple of the input resolution?) I find that linear (as in bilinear) scaling from very small resolutions up to large resolutions (320x200 -> 1600x1200) is too soft to look good. Point sampling from small resolution up to a large resolution does look better, although not perfect if the scaling is not an integer multiple.
CRT Terminator's "MultiMode output" combines point sampling and linear sampling in coordination with the flat panel display's "Force 4:3" mode to find what I think is the best balance of both worlds. See e.g. the Pinball Fantasies screenshot at https://oummg.com/USB3HDCAP_Pinball_Fantasies.png , or here are other examples of upscaling from 640x480 up to 1600x1200 in the Windows 3.11 installer:
https://oummg.com/media/win311_mouse_crtt_640x480_upscaled_1600x1200.png
https://oummg.com/media/win311_installer_crtt_640x480_upscaled_1600x1200.png
which shows a balance of being crisp, but not exhibiting point sampling aliasing.
Not sure what you compare to by "same" here, though yeah, if an EGA card did 800x600, then that would allow a nice passthrough conversion to DVI-D, or e.g. 2x integer upscaling to 1600x1200.
One drawback with EGA and CGA outputs is that they do not provide a pixel clock signal on the wire, so clock reconstruction techniques need to be applied at receiver in order to acquire a good signal for flat panels which require a pixel clock for TMDS+LVDS processing. This is of course possible, but requires some care. Feature Connector does provide the video pixel clock directly at a pin, which makes life simpler.