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New development: GTIA in CPLD


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The new CPLD solution is already working. Features:

  • Standard RGB output
  • Sharp, clean image
  • True 256 colors
  • 16 luminance levels available in all graphics modes.
  • Two colors in hi-resolution graphics
  • P/M colissions, trigger inputs and consol keys are supported by the old chip.

The tests takes some time. The decision on the mass production depends on the interest.


Edited by Simius
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I'm sure there are some high end TV's that support RGB, but the most I've seen have HDMI, YPbPr, composite, and sometimes VGA.

There's also professional monitors like the Sony PVM and BVM series, and you also have upscalers like the Framemeister that can take RGB and output HDMI.


And let be known that I am *very* interested in this. If you want someone to test this in a 5200 that can be arranged...

Edited by ApolloBoy
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Nice - is the low bit capability for palettes selectable on/off like VBXE ? Also I assume GTIA bugs and quirks are reproduced, e.g. persistent PM via size change trick and multicolour mode when PRIOR is changed from GTIA back to normal on a hires line.


I have to agree though, Component video would be way more desirably than RGB. 16 KHz RGB monitors are just a rarity where Component is almost universal on modern TVs.


Another nice addition would be the ability to half shift Gr. 10 pixels to the left so they match other modes. This is one of those mystery things that is rumoured to be possible on normal hardware but not yet verified.

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@ApolloBoy, Mickcris, Lilralphie

There is no reason not work in 5200, since it is originally equipped with GTIA, but I'll try to remove the doubt.

@Mytekcontrols, CharlieChaplin

I'm not sure, but I suppose about US$50-60.


All color registers are eight-bit, so yes, GR.10 also have 16 luminances.


Of course.


1. No, the least significant bit of luminance isn't on/off, athough could be if you can propose a proper, free bit in some GTIA register.
2. I don't know but if you can point some test program, I can check it out.
3. There is no problem with the positioning GTIA-mode pixels relative to hi-res graphics. As above - give a test.


It isn't a stupid question. It will work, but the pinout of GTIA is different than FGTIA and there are significant differences in the TRIGs inputs handling, so different CPLD firmware and an adapter (or another PCB version) would be needed.

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