Awesome work, Yeo! Sorry if I'm asking a duplicate question, but have you considered submitting this to Hackaday?
They have already written an article about it :)
https://hackaday.com/2023/09/10/upgraded-graphics-gremlin-ad...
HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin
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Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin
#52What kind of command.com they use? I don't remember any with autocomplete.
I used Enhanced Doskey. http://paulhoule.com/doskey/
Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin
#53Earlier quoted context omitted.
That's only the case in the (relatively) shiny new 2.1 spec with FRL. Prior versions are TMDS with 3 channels for red, green, blue, along with a clock. The audio and InfraFrames slot into the data islands in blanking periods on those signals.
Thanks for the complementary infos. YCbCr420 (which you can't just mux on the channels directly?) dates back to HDMI 1.4 though
Absolutely - YCbCr 4:2:2 and 4:2:0 use different encodings across the lines to balance bandwidth. Complexity then continues to stack with deep colour pixel packing. There's a beautiful pocket of simplicity for RGB 4:4:4 8bpc which is essentially a direct digital encoding of ye oldy RGBHV signals. More than OK for any retro-comp needs, and a fun starting point for general hacking.
Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin
#54Earlier quoted context omitted.
Kids nowadays will never understand how cool it was to have a Sound Blaster, an Athlon Thunderbird and Voodoo graphics. I might be nostalgic, but to me it sounds much cooler than having a 11700k with a 4090 nowadays
There was a time before Pentium when hardware was not named with trade name but by standard it implements. For instance you had your 486 with VGA, were it Cyrix CPU with Trident graphics card or Intel CPU with S3 graphics card didn't matter much. For consumers only sound expansions broke this mold because they came with cool names such as Sound Blaster, Gravis Ultrasound, etc. They carried that over from audio market…
I thought the Sound Blaster AWE32 was nicely named .. Advanced Wave Engine, indeed .. helped them differentiate from the same technology being touted by Yamaha at the time, if I remember correctly ..
Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin
#55> The frequencies and connectors used by CGA and MDA are no longer supported by modern monitors hence it is difficult for older PCs of the 1980s era to have modern displays connected to them without external adapters. Some CGA ran over composite, and there's plenty of modern small TVs with a composite input. It's perfectly fine to use a TV as a computer monitor. (I do!) > This analog-to-digital conversion will also l…
Count me in as someone who likes vintage hardware but modern displays. In my case it's old game consoles. The drop in video quality with composite is real. This has less to do with the resolution, but more with the fact that hardware that upscales this to an HD or 4K panel needs to make an educated guess where pixels start and end, and gets it wrong. It looks quite ugly practically and switching to something with cri…
> Count me in as someone who likes vintage hardware but modern displays
I should also add that, if you change the graphics card in an old PC, you're inserting a huge variable when it comes to playing a game on "vintage hardware."
Some games resorted to various tricks, whatever, that might not be emulated correctly on the new graphics card.
Again, that's why I find the idea of a "modern" CGA silly: When you use it, you no longer have vintage hardware, and the CGA connector is digital so there's no need to worry about a loss in quality.