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New development: GTIA in CPLD


Simius

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Super IRG demo #1 is finished. Anyone who has this enhancement, please test it.

 

Firstly, run the "SUPERIRG.BAS" program. The colors have been set to blend a 16th step apart and should not flicker really badly, with the exception of the colors that blend with the background.

 

Secondly, I have modified ICEIRG (The ICE editor for super IRG modes) to work with the 16 steps, and to also alter the hi-res color in the two Hi-res modes (Super 0 and DIN) independently of the background. Can someone test this and see if it works? Run ICEIRG.TUR, then in the Super 0 mode, go to the color tuner and try to change the text color. Also use "G" to cycle to the DIN mode and try to change the color there too on the text.

 

Please let me know what results you get. My next test is going to be in the GTIA modes, with a modified Graphics 10 at 45 colors.

 

post-23798-0-31018900-1486625347_thumb.png

iceirg2.atr

Edited by Synthpopalooza
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Super IRG demo #1 is finished. Anyone who has this enhancement, please test it.

 

Firstly, run the "SUPERIRG.BAS" program. The colors have been set to blend a 16th step apart and should not flicker really badly, with the exception of the colors that blend with the background.

 

Secondly, I have modified ICEIRG (The ICE editor for super IRG modes) to work with the 16 steps, and to also alter the hi-res color in the two Hi-res modes (Super 0 and DIN) independently of the background. Can someone test this and see if it works? Run ICEIRG.TUR, then in the Super 0 mode, go to the color tuner and try to change the text color. Also use "G" to cycle to the DIN mode and try to change the color there too on the text.

 

Please let me know what results you get. My next test is going to be in the GTIA modes, with a modified Graphics 10 at 45 colors.

 

attachicon.gifsuper irg demo.png

 

I don't have the enhancement to check this out but I was curious anyway. When I mount the ATR and take a look at the disk there is no SUPERIRG.BAS file on it.

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Two more Super IRG demos, these should show better what this new device can do.

 

The first one has color settings which are of a variance of 1/16 luma. There should be 10 colors on one scanline which have minimal flicker ... the other 4 blend with the background so will flicker more.

 

The second one uses monochrome settings which step up gradually by 1/16 luma. This should give you about 10 level shading in Antic 4 resolution, with 1/32 luma steps.

 

I took these screenshots in the emulator. I would like to see what these look like on real hardware. The second one doesn't show all the luma steps in emulation, because Altirra does not yet support 16 level lumas which this device enables.

 

Run TEST1A.TUR and TEST2A.TUR ... someone please tell me how the flicker is with these on real hardware running with this new device. Especially on PAL.

 

post-23798-0-93632700-1486790214_thumb.png

 

post-23798-0-66674500-1486790234_thumb.png

iceirg2.atr

Edited by Synthpopalooza
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I have also done a demo in DIN mode ... this is a Antic 2 and Antic 4 flicker mode.

 

In this, I have set the luminances of the Graphics 0 text, and three of the PF colors, to the same luminance to reduce flicker. The program will also cycle the Graphics 0 text color through all 16 luminances slowly. If you are running using the new GTIA device the letters should be seen to change color.

 

I used the other PF color for text shadowing, but you could also use this for another set of letters in a 4th color.

 

Run DIN1.TUR ... the memory locations are as follows:

 

712 and 1045: BG color (keep these two the same)

708: PF0

1043: PF1 color in Graphics 0

1042: PF1 color in Antic 4

1044: PF2 color in Antic 4

711: PF3 color

 

You can try altering these in the program if you want to play with the colors ... the program cycles 1043 through 16 chromas repeatedly.

 

post-23798-0-93306500-1486793271_thumb.png

iceirg2.atr

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I'm going to do some Super IRG experiments which take advantage of the new features of this device ... specifically the independently programmable COLPF1 in Graphics 0, and the 16 step luminances. It should be possible to dramatically reduce the flickering in these modes if you blend using the 16 step luminances. I don't have the device available, so I will be relying on others to test this for me. The key is how well it will look in PAL, without frameblending.

 

Any tricks using the properties of the PAL system, like the adjacent lines color blending, will not work. Here is no PAL encoder, but direct color outputs.

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On the older, 26" Samsung LCD TV in the interlaced mode the image is the same as at the Nir's pictures.In the non-interlaced mode a flickering appears. NTSC computer, component output. The same TV, the same computer, S-video input - colors are blended, no flickering.

Edited by Simius
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Another demo ... this time in the PCIN mode.

 

This is a Super IRG mode that switches the GTIA register between an Antic 2 or Antic 4 mode, and Graphics 10. While this mode can produce less flickering, it is fraught with it's own problem: The Atari's GTIA shifts the Graphics 10 pixels one color clock to the right, which makes the pixels not line up properly. Some programming involving playing around with the HSCROL register in VBLANK is needed to get the display to line up properly ... at the cost of VBI cycles.

 

The new SOFIA device fixes this problem. The Graphics 10 pixels are not shifted. While this means that, sadly, HIP mode and other graphics mode which rely on this shift to increase resolution in GTIA modes, will no longer work, it also means that implementing the PCIN mode is easier. No HSCROL shift is needed.

 

I've attached an example pic, a converted Commodore 64 FLI. In this case I have left the pixels un-shifted. It will be out of alignment on a standard Atari, but with the new SOFIA board, it should look properly. The colors are optimized for NTSC so they will look different in PAL.

 

Also attached is an updated ICE CIN font editor, which now supports the hi-res color in the PC0, C0, and M0 modes, and the 16 step luminances. I have not yet been able to fix it for the non-pixel shift in SOFIA yet so the font display in the PCIN modes will look blurry.

 

post-23798-0-26761800-1486965306_thumb.png pilgrims-pcin-sofia.obx

 

Also attached is a screenshot of the ICE CIN editor in PCIN mode. On the character grid on top, you will see artifact lines on the left and right. These should disappear when using the SOFIA board. I would appreciate it if someone could test these. :) Thanks

 

post-23798-0-74378000-1486965854_thumb.png

 

When booting the .ATR, RUN D:ICECIN.TUR, and then press "L" and enter "D:WALLPCIN.ICE" to load the example font set from the .ATR to see the screen above.

 

 

 

icecin-2.atr

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