Hercules graphics card question

[giobbi]

This has come up before;

sorry I missed it...

the general consensus is that these are built for taking RGB TTL video and converting it to 8-color analog RGB output via VGA. IBM CGA (as well as Commodore 128 CGA) is RGBI, which is 16 colors, so if you use one of those converters you get less colors, and the output of yellow isn't correct because IBM/C128 CGA monitors change the color of yellow to dark brown in their internal circuitry.

hm, this part isn't clear to me (my fault, sorry)... I remember that CGA was 3 colors + black, two palettes... 16 colors was EGA, wasn't it?

There are various homebrew adapters that massage CGA TTL into VGA; here is one such success story, with pictures/video: http://www.vintage-computer.com/vcf...ive-CGA-Video-Capture-Using-Startech-PEXHDCAP

Great, I didn't know it, I will take a better look later. thank you.

 

[Scali]

Nice, I didn't know.
Must it be the 1084S or a simple 1084 will be ok? The "S" stands for Stereo or I'm wrong?

I'm not sure really, I've only seen 1084S ones (you want stereo for your Amiga). You'd just have to check, there should be a 'TTL RGB' input on the back (usually a DIN plug, I think it is 8-pin).

 

[Scali]

hm, this part isn't clear to me (my fault, sorry)... I remember that CGA was 3 colors + black, two palettes... 16 colors was EGA, wasn't it?

CGA has 16 colours in textmode, the palettes in graphics mode select 4 colours from these possible 16.
They are formed by red, green, blue and intensity (RGBI) signals.
EGA has a total of 64 colours, because it has three intensities, one for each primary colour. It has a palette of 16 colours from these possible 64.
Note that the 64-colour only works in the high-res 640x350 mode. In 200-line modes, it only has the fixed 16 colours, to remain compatible with CGA monitors.

 

[vwestlife]

Nice, I didn't know.
Must it be the 1084S or a simple 1084 will be ok? The "S" stands for Stereo or I'm wrong?

Yes, the S stands for Stereo. Many Commodore/Amiga monitors will work with CGA, since the Commodore 128's 80-column RGB output used the same pinout and video signal specs as CGA. Just look for a "TTL RGB" input on the back. Be careful when obtaining a video cable, though, as even the same model of monitor might have one of several different styles of video input connectors on the back (D-Sub or DIN) depending on the monitor's OEM (Philips, Samsung, Daewoo, etc.).