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HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

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31–40 of 55 posts

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#31
I’d love to see something like this for late 90s through mid 00s computers, because many of those machines can still find modern uses but are awkward to use with modern high-resolution displays, even if they can sometimes be adapted digitally (DVI-equipped machines). Of course you can always grab an old monitor to pair with said machine, but that comes with heavy picture quality concessions in the case of LCDs, and good CRT monitors are becoming rare and expensive.

So for example it’d be super cool to be able to drop a new GPU into a PowerMac G4 tower and allow it to drive a modern 2560x1440 display under both OS 9 and OS X.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#32
post #29

> 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 crisp pixels is usually very worth it.

For old game consoles it's often enough to switch to RGB or Component and you don't have to go full digital. Composite (and RF) are quite bad.

This is not an audiophile type of distinction, it's very visible and obvious to almost anyone.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#33
post #24

Earlier quoted context omitted.

"Sound Blaster" was the original funny name - these are both derivations in a modern style, given to clones of that ol' sound card .. and yeah, they are hilarious names, and I hope the trend sticks, personally .. the world tires of X3000-style naming conventions, I'd wager, and for fun things like sound cards and video cards, a bit of naming whimsy would be welcome.

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 where equipment had "cool" names for some time already (since 70s at least).

Interestingly, Intel made "Pentium" trademark to distance and distinguish themselves from other x86 CPU vendors, but Creative failed to protect Sound Blaster trademark in a way that in mid90s everyone called every OPL3 card "a sound blaster". In that age real Sound Blasters had quality synthesizer, big wavetable with a quality soundfont and a DSP for effects on top of it, a feature which became less and less relevant as 90s went by. In mid 90s games were already moving to MIDI+CD Audio combination and by late 90s MIDI based soundtracks were largely gone. When you were playing Duke for the first time the type of "sound blaster" you had and hardware around it mattered. A clone would render worse MIDI than real Creative hardware and then came the external hardware such as Roland SC series, etc. The differences were real. When you were playing Half Life or UT for the first time just a few years after, there was no difference.

So Creative never managed to actually stamp "Sound Blaster" with something particular. It always remained a synonym for the entire standard and something even cheap hardware was described by. "Sound Blaster Audigy" was mostly reffered to as Audigy or Creative Audigy and it didn't have an ubiquitous meaning because it was clearly separated from all the junk audio cards of the day.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#34
post #4

I've worked on something similar while in college. HDMI is actually a fairly simple protocol, based on VGA. It still has scanlines and such, but the signals are digital instead of analog. So instead of a RAMDAC, you have the HDMI encoder chip. You typically need control some i2c interface to set the HDMI encoder chip in the correct mode, but that's about it.

It's worth mentioning that HDMI encoder chips are actually quite difficult to get hold of as a hobbyist; the HDMI association prohibits their sale to anybody who has not signed the relevant NDAs, paid membership fees and whatnot. The project shown here gets around this by using a freely available DVI encoder chip instead, which works fine (the HDMI specification mandates backwards compatibility with DVI) but lacks su…

This is a good reason to bit-bang the protocol. It is in fact possible to get HDMI including audio out of an RP2040, as is demonstrated by infones[1], a NES emulator.

[1]: https://github.com/shuichitakano/pico-infones

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#35
post #4

I've worked on something similar while in college. HDMI is actually a fairly simple protocol, based on VGA. It still has scanlines and such, but the signals are digital instead of analog. So instead of a RAMDAC, you have the HDMI encoder chip. You typically need control some i2c interface to set the HDMI encoder chip in the correct mode, but that's about it.

How does its complexity compare to DisplayPort?

HDMI is simpler to have a simple implementation; DisplayPort is simpler to have a fully featured implementation.

HDMI keeps normal analog video timing with blank/hblank, etc. Stuffing anything other than video is pretty complex and a mish mash of finding weird gaps in the video data.

DisplayPort is it's own packet based protocol. Sending things other than video are just other packet types over the same link.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#36

I’d love to see something like this for late 90s through mid 00s computers, because many of those machines can still find modern uses but are awkward to use with modern high-resolution displays, even if they can sometimes be adapted digitally (DVI-equipped machines). Of course you can always grab an old monitor to pair with said machine, but that comes with heavy picture quality concessions in the case of LCDs, and g…

Just be aware that old machines can bog way down when you start asking them to push millions of pixels. Their old graphics subsystems were never designed to handle that much data, bus widths are a major bottleneck.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#37
I have a couple of vintage computers. One is my original first computer. While there is a cheap expansion that would allow me to hook up any VGA screen on it, the part of the experience is the screen.

I've been hooked on to retro computing a while, and I flatted out somewhat. It all depends on what you want to do. If you want to play games or run software I suggest you take a good deep look at the emulators. I had a task to do with my XT and that was pulling the data out from it. I did some original programming for that purpose. I spent days loading software from the internet to it in minutes which was kind of miraculous. I programmed some graphics demos on it. I upgraded it with an XT-CF, etc. In the end there is no need to keep that machine up and running on a desk somewhere. The best purpose would be aesthetic, because it is really beautiful as a package, but even if it were in mint condition, I wouldn't risk running it for a couple hours daily for an useless purpose. Although it would be nice to have an 80s style terminal displaying current whether, RSS feeds, etc, it's just a bad way to run your historic machine out of working hours.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#38

I’d love to see something like this for late 90s through mid 00s computers, because many of those machines can still find modern uses but are awkward to use with modern high-resolution displays, even if they can sometimes be adapted digitally (DVI-equipped machines). Of course you can always grab an old monitor to pair with said machine, but that comes with heavy picture quality concessions in the case of LCDs, and g…

Just be aware that old machines can bog way down when you start asking them to push millions of pixels. Their old graphics subsystems were never designed to handle that much data, bus widths are a major bottleneck.

Yeah that’s a good point. There’s definitely some machines in that bracket that are capable since with the right GPUs they could drive similar contemporary displays though (G5 tower with circa 2005 2560x1600 Apple display for example), and it’d be great to not be restricted to only those old GPUs to gain that capability.

For older machines even cleanly driving a new 1920x1080 display without a dongle would be a nice upgrade.

Re: HDMI ISA graphics card for vintage PCs by improving the Graphics Gremlin

#40
post #4

I've worked on something similar while in college. HDMI is actually a fairly simple protocol, based on VGA. It still has scanlines and such, but the signals are digital instead of analog. So instead of a RAMDAC, you have the HDMI encoder chip. You typically need control some i2c interface to set the HDMI encoder chip in the correct mode, but that's about it.

If you only want to drive the monitor in DVI compatibility mode, you don't need very much because the interface is (as you describe) fairly simple and electrically compatible - if you actually want "real" HDMI then it's much more complex.
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