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Author Topic: REQ: Someone Mass-Produce Scandoubler/Flicker Fixers  (Read 11354 times)

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Offline DamageX

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Re: REQ: Someone Mass-Produce Scandoubler/Flicker Fixers
« on: October 08, 2005, 05:54:42 AM »
This may not be a bad idea. Something like a scandoubler/deinterlacer which is useful not only for Amiga but for other games/computers might sell enough to get the production cost down.

Look at this (TrueView 5700):
http://www.tvia.com/index.cfm?page=body&crid=16

From the information given I think it needs an SDRAM chip and a microcontroller or something to go along with it.

P.S. while we're at it I would like to see a memory board that plugs into both A2630 or Zorro3 and has either SIMM sockets, DIMM sockets, or 8MB of SRAM (zero waitstates)
 

Offline DamageX

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Re: REQ: Someone Mass-Produce Scandoubler/Flicker Fixers
« Reply #1 on: October 09, 2005, 06:55:19 AM »
If one wanted to use a PC to do the job, one might as well get a TV tuner card since those are pretty cheap on ebay. It would be nice if there was one with RGB input though, anyone know if such a thing exists?

Any "flicker fixer" needs to have enough RAM to buffer the whole display, close to 1MB at 24bpp (well I guess a clever device could get away with only a little more than half that much RAM, buffering only the previous field and previous scanline). I wonder if the Averlogic chip has enough RAM on it to do this.

One could use the digital video signals at the video slot instead of converting A->D but that would limit the systems that you could use the device with.

Maybe designing the logic from the ground up would be the way to go? Maybe someone who knows more than I do can help me out with this...

1) First thing needed would be a set of ADCs for the RGB input (minimum 16bpp but preferably 24-bit)
2) some logic that can sample the input at 14.3MHz (28.6MHz if we need super hires ECS modes...) and generate the proper addresses to write the data to odd/even lines of a framebuffer in RAM (720x480... unless we need extra lines for PAL or super hires again)
3) set of DACs for VGA output
4) logic to generate sync for VGA output, and count addresses for reading the output data from the framebuffer
5) memory that can handle this bandwidth... (dual-ported SRAM??)
 

Offline DamageX

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Re: REQ: Someone Mass-Produce Scandoubler/Flicker Fixers
« Reply #2 on: October 17, 2005, 03:46:42 AM »
I wouldn't worry about the difference between 18-bit RGB and 24-bit RGB, as long as we're talking about 6 bits per component. It would be a vast improvement over 12-bit or the screwy 8:4:4 that has been mentioned.

The extra precision of 24-bit would only be noticable under certain circumstances (for instance, doing gamma correction in software instead of using the controls on your monitor)