Re: Let's pay a developer to make a VGA output card

[Mark McDougall <markm@vl.com.au>]

heuser.marcus@freenet.de wrote:

> Give me a graphics option that looks like the output of an old 14'' 
> color monitor of yore. Give me pixels that aren't square or blocky
> but smear into their neighbours. Give me pixels that get "thicker" in
> height and width the more contrast the picture has.

Seems there are two distinct schools of though here...

The primary reason for wanting VGA of course is being able to use 
existing VGA monitors, whether that's simply for space-saving (which 
would be my reason), an ever-depleting stock of compatible monitors, or 
simply convenience.

One 'school' would appear to be happy with 'perfect' display quality - 
the crispness of modern displays as is possible on the emulators. 
Arguably, a simple 'scan-converter' is out of the question for this 
purpose. To add complexity, there's also the 'artifact' mode which would 
have to be implemented, even if it results in a similarly 'crisp' display.

Then there's the school that want an exact replica of the old analogue 
output with features such as Marcus has listed above. These features are 
ironically more difficult to produce artificially from a pure digital 
source. Perhaps a scan-converter of sorts would be more suitable here.

Personally, I like the idea of the 'bus snooper' with its own frame 
buffer to produce VGA output. Yes, without any processing it would 
result in the 'clinically sterile' output but with a more capable (and 
costly) design these issues could be addressed somewhat.

I've had some experience with FPGAs and VGA generation and I am sorely 
tempted to build a prototype card... I have a few ideas of what else 
could go on the card as well. But can the A2 hobbyist market support the 
cost of even just producing such a card? I'm debating that myself...

Regards,

--
Mark McDougall, Engineer
Virtual Logic Pty Ltd, <http://www.vl.com.au>
21-25 King St, Rockdale, 2216
Ph: +612-9599-3255 Fax: +612-9599-3266