Native CGA Video Capture Using Startech PEXHDCAP

[chjmartin2]

Hi,

I will post a lot more on this later. I bought a Startech PEXHDCAP, grabbed a TTL to Analog RGB converter (For C128/CGA) and rather than running it into a VGA Resyncer the PEXHDCAP can handle the 15 KHz signal directly. Woot. I can tell you that even 60 HZ Flicker effects capture beautifully on this card. Fun stuff. So happy that it worked because I was not sure it would.

Here is a teaser:

 

[chjmartin2]

And another...

 

[chjmartin2]

Would like to know if anybody would know how I could figure out how to make/buy an EGA TTL to Analog RGB converter. I know this card can capture 15 Khz, wonder if it can sync to Ega 23 KHz....

 

[Great Hierophant]

Very impressive, I can see the brown in your Archon video. I'd like to see some geniune 60Hz/fps capture. Of course, you will need to upscale the video for that.

Would like to know if anybody would know how I could figure out how to make/buy an EGA TTL to Analog RGB converter. I know this card can capture 15 Khz, wonder if it can sync to Ega 23 KHz....

I think most people would simply use a VGA capture device, the pixels are not. However, several arcade games use refresh rates in the low 20s, so it may be possible.

 

[chjmartin2]

Very impressive, I can see the brown in your Archon video. I'd like to see some geniune 60Hz/fps capture. Of course, you will need to upscale the video for that..

Here is a link to a Transport Stream captured at 60 fps. It is the flicker encoder Heman intro on 8088 Domination.

 

[Trixter]

a TTL to Analog RGB converter (For C128/CGA)

Which one? Are these available for sale, or did you build one from a schematic? If so, was it this one: https://groups.google.com/d/msg/comp.sys.cbm/ARbaCb8n9Sg/B0UPWvrKOaUJ

 

[archeocomp]

Please post links to what you bought so that we can buy and try it out too

 

[chjmartin2]

Which one? Are these available for sale, or did you build one from a schematic?

http://he-insanity.blogspot.com/2014/03/commodore-128-cga-video-dac-board.html

The board is available at the link. He recommends combining it with a GBS 8220 Arcade Scaler, but that is not what I did. I bought the PEXHDCAP and then made this:



I connected the RGB outputs to RGB, Horiz Sync and Vertical Sync to the appropriate pins and then ground for a whole bunch of pins. I feel like if I had a capacitor between R/R return, G/G Return, B/B Return but no idea what the right value would be. But it does work great.

 

[Chuck(G)]

Since this is under "PC", does the setup correctly do the translation for yellow-to-brown? Or does it look like yellow?

 

[chjmartin2]

Since this is under "PC", does the setup correctly do the translation for yellow-to-brown? Or does it look like yellow?

It shows Brown. Not quite right, but it is what it is.

This picture makes me feel like I have channel cross talk. Maybe I shouldn't have twisted Blue and Green together.... hmmmm...

 

[Trixter]

Colors, including brown, look pretty damn good to me!

 

[chjmartin2]

Colors, including brown, look pretty damn good to me!

Make no mistake - I love it - I just think the brown is a tad bit lighter than life. I am super pleased with it. I do wish I knew how to clean up the little bit of noise I can see.

 

[chjmartin2]

More Screen Caps

More Screen Caps

 

[chjmartin2]

 

[chjmartin2]

 

[chjmartin2]

 

[chjmartin2]

 

[chjmartin2]

 

[chjmartin2]

Thought you might like some additional screen caps. There are 16 color images but everything is RGBI captured through a DAC. Not pixel perfect but really darn nice.

Chris

 

[cr1901]

No doubt a real CGA monitor could display all these images, but I'm guessing that some of these images couldn't actually be generated by a physical CGA card due to framebuffer limitations? I.e. each bit represents a dot in 640x200 mode, on-board logic selects 4 colors from a palette of 16 colors in 320x200, etc. The monitor doesn't care, but a real CGA card would never feed a CGA monitor a 16-color image in 320x200 without some fancy tricks (I'm not part of the demoscene for a reason ).