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Interlaced Character Editor 1.0 wins 4th place in ABBUC Contest


Synthpopalooza

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Well, looks like my font editors won 4th place in ABBUC. :)

 

ICE is a series of font editors that work with special character-flip text modes that enable the display of extra colors onscreen through VBI swapping. There are 20 different graphics modes supported, which can display anywhere up to 256 colors onscreen at once.

 

Attached are three ATR's, plus the insctuction manual as a .PDF, and also some articles I wrote for AtariUser documenting most of these new Graphics modes.

 

To use ICE, I recommend any Atari with 64K RAM. You can run this on a PAL machine, but NTSC gets better results because of the faster refresh rate. For Emulation, Altirra is recommended. Atari800Win is not recommended because there are issues with displaying some of the CIN modes, and the screen flicker refresh rate is horrible on it.

 

The ATR's are:

 

iceirg.atr - Edits in Super 0, Super IRG, Super IRG 2, and DIN

icegtia.atr - Edits in the GTIA modes (including Super 9, Super 10/10+, APAC, and HIP)

icecin.atr - Edits in the CIN modes (3 variations each of CIN, MIN, and PCIN)

 

I will be working on updates to these programs as I get time, and also I am working on new ICE editors for the Super IRG modes based out of Graphics 1. Examples of these modes can be seen in this thread.

 

Some screenshots:

 

post-23798-0-22309300-1320252595_thumb.png

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post-23798-0-91769500-1320252698_thumb.png

post-23798-0-56546800-1320252738_thumb.png

ice abbuc 1.0.zip

super irg modes 2.zip

super irg modes.zip

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I have some German speaking friends (and Polish) so I can have the manual translated if you like.

 

In fact, Kaz over on atarionline.pl has been translating my AtariUser articles on the ICE modes into Polish.

 

I guess this project has had a lot of effort, it's taken me 2 years of experimenting to get to this. I'll be really happy if, hopefully, some new games and demos come out of these ICE modes.

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Hi,

on my (130xe) PAL CRT tv all the programs flickered; I didn't get the nice displays you have above - are the programs usable on PAL or should I try another TV?

The programme is best viewed with emulator altirra. There you can blend out the flickering. Real machines will have the flickering, while PAL ones will flicker more than NTSC ones. It´s the matter of all interlacing technics. But as seen in Space Harrier it is not a matter at all. For sure a textadventure would be very hard to read. Edited by pps
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The programs will flicker more if you are on a PAL machine. One thing that can help with this is using a monitor with a scan doubler. Also, when selecting your colors, watch your luminances, you don't want to vary the luminance between flickers by more than 4 steps, this will reduce the flicker in your designed character set.

 

There are also methods to use these character fonts in scanline mode (that is, changes are made per scanline). The limitations are, you can only do it in assembly, and it has to be a graphics mode which doesn't do display list swapping (this means you can't use DIN, or Super CIN/MIN/PCIN)

 

Also, if you are using Super IRG, Super 10, or the two PCIN modes based out of Antic 4, you can do a dithering pattern on your characters when using solid color fields. This is easiest to explain in Super IRG. The reason this works is because Super IRG and the other modes do not shift any of the color registers. Here's an example screenshot, first of the two font masks, then the resultant character:

 

post-23798-0-65637500-1320780509_thumb.png post-23798-0-82247100-1320780546_thumb.png post-23798-0-66860700-1320780567_thumb.png

 

Keep in mind that the cursor in this example is in the top left corner of the character grid.

 

If you will look at the palette bar (0-9 a-f) you will find some colors are identical. I call these "dithering pairs". In this case I am using colors 6 and 9 as my dithering pairs, these two colors are the result of blending PF0 and PF1, but on alternate frames. You will use one of the dithering pairs on alternate spaces on the grid, making a checkerboard pattern, filling in the spaces left with the other dithering pair color. This will reduce your flickering.

 

The method also works on Super 10, and on the PCIN (Gr. 12 + Gr. 10) modes, except that the pattern will be 2x8, and in PCIN you have to use 2 pixels on the Graphics 12 side of the display, paired with one pixel on the Graphics 10 side. Also, you can only do this with PF0-PF2 in this mode (or PF3 if you use Super PCIN) as these are the color registers shared between Graphics 12 and Graphics 10. I've included screenshot examples for Super PCIN:

 

post-23798-0-44417700-1320782385_thumb.png post-23798-0-70651800-1320782404_thumb.png post-23798-0-97292700-1320782419_thumb.png

 

In this example the dithering pairs are "7" and "A", these will blend PF1 and PF2 on alternate frames.

 

There is some striping in the character grid, because of the Graphics 10 pixel shift, but you will notice in the typing area this same character looks properly.

 

One feature I am considering for future versions is automatic color dithering in modes which support it. I know Bill Kendrick did this in his own SIFE Super IRG font editor.

 

Also, if you're trying to design readable text for a text adventure or a title screen, I've found that the DIN (gr.0 + gr.12) mode works best. You are blending pixels at a higher resolution (320 mixed with 160) and with careful color selection you can get a nice display. This is the mode I used for the ICE IRG Super Mario style title screen.

Edited by Synthpopalooza
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There are more tips to reduce flicker.

 

If you are using HIP 0 or the MIN modes and using only monochrome values, you will also want to keep your luminances within a range of 4 when mixing. I think HIP 0 (like the bitmap version) lets you have 32 shades, while MIN reduces it to about 24, although your pictures will be less fuzzy.

 

You can also do dithering pairs in the MIN modes too. You need your PF0-PF3 settings to be 4-8-10-12 ... you get 5 level shading in Graphics 12 mixed with 16 level from Graphics 9. Intermixing with the even level shades in Graphics 9 creates the dithering pairs.

 

Here's an example of a solid color field in Super MIN, using dithering pairs:

 

post-23798-0-32493800-1320799392_thumb.png post-23798-0-23341600-1320799430_thumb.png post-23798-0-45178300-1320799641_thumb.png

 

Careful selection of colors is needed to create this effect. Remember to mix with even shades in Graphics 9 to do dithering on solid color fields. In theory you get 80 possible colors, but by limiting your lum difference by 4, it's closer to 24 shades, roughly.

Edited by Synthpopalooza
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  • 1 year later...

About a year and a half on, and I am working on updates to the ICE font editors. Here's what's in the works:

 

Updating ICE GTIA to do a better rendition of Super 10+ without the need for the character and font views.

Adding support for PCIN+ (Graphics 12+10 at 45 colors) to ICE CIN editor.

Support for editing Graphics 0 based modes (Super 0, DIN, PC0), in 8x8 mode (no artifacting)

 

I will be writing some new font editors as well:

 

ICE GTIA lo-res, is for doing GTIA mode fonts (Super 9, 10, HIP, APAC) but in Antic 5.

ICE IRG 20, will be for 20 character wide GTIA modes using Graphics 1.

ICE DIN 20, will be for 8x8 modes which blend Graphics 1 with a GTIA mode.

 

 

Here are some WIP screenshots from ICE IRG 20:

 

post-23798-0-09514300-1359862420_thumb.png post-23798-0-32208200-1359862908_thumb.png post-23798-0-49064000-1359862923_thumb.png

post-23798-0-93741500-1359862944_thumb.png post-23798-0-83227300-1359862968_thumb.png post-23798-0-54437400-1359863097_thumb.png

 

Modes shown:

 

Super IRG 20 ... Interlaced Graphics 1.10 with about 36 colors, 9-16 per char cell, over 9 palettes

Super 9/20 ... Interlaced Graphics 1.9, 100 duo-tone shades with 16 colors per char

HIP 20 ... like HIP mode but using Graphics 1, about 70 colors with a simulated 8x8 char resolution

CHIP 20 ... like HIP 20 but blending Graphics 11+10, 70 colors

Edited by Synthpopalooza
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  • 2 years later...

Something I recently discovered is going on with Super-IRG mode graphics with HDTV and using a video converter to VGA. That instead of frame blending, it is actually interlacing the pixels in alternate pixel rows. As some of you know, I made a few games that use this Super-IRG style. At first I thought it was only displaying the game at 30 frames per second and not 60. But closer inspection did indicate all the pixels are there. This game is designed for non-interlaced displays that are either Composite, Chroma-Luma CRT displays. I know these things are rapidly disappearing as everyone is using flat-screen TVs. One work around is to just alternate the character sets every 2 frames instead of 1. I know the flickering would become more obvious.

 

This could be an alternative for creating 480i mode instead of doing that trick with the DMA control register. You can just alternate 2 character sets with DLI at the top of the display.

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I would be most curious to see a screenshot or a video of your game being played on your HDTV to see what is happening.

 

Some ICE modes (like DIN, or some of the GTIA modes) rely on full-frame flicker as opposed to the checkerboarding that you can do with Super IRG, so it might affect the output.

 

There was also that Tetris game I remixed for Itay, which also uses an ICE CIN mode (CIN 12 or CIN lo-res, Graphics 12+11, 160x192 pixels at 60 colors) but alternates the mode by scanline rather than full frame. I would be keen to see how all these examples translate to modern HDTV's.

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Would need some sort of screen capture device because this is not emulated with Altirra properly. Interlace mode only works with setting the DMACTL register, I am still not sure how that works or at which points the DMACTL is turned on and off. My TV-Tuner card only displays at 30 frames per second, so that only shows only one character set.

 

Updates to my games may not be necessary yet because vast majority of the people playing the game are using CRT non-interlace displays that blend two character sets together.

Edited by peteym5
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Ahh, so the game skips every 2nd frame on this TV, if I understand correctly? So that, in a typical Super IRG display with a checkerboarded character set, you just see a solid checkerboard?

 

Blending the frames at 25 frames per second (or 30) will not look that good at all, to be honest. I had heard that some modern LCD TV sets will do the frame blending automatically, so there might be a setting on your TV to play around with.

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  • 2 years later...

Has there been any updates to Interlaced Character Editor since version 1.0? I can see there are a few bugs in the program, maybe I can fix them myself and upload it back here. I am considering using it to help with some of the graphics for games like Secretum Labyrinth that uses Super IRG extensively. I have been using Envision font editor, but I cannot see results until I compile the program with the fonts. Very Tedious.

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  • 1 year later...

Necrobump ... thanks for the update.  I have done a small update to ICE (all versions) but it was one which lets you increment the luminance by one step instead of the two steps normally supported by the 8-bit.  This is for benefit of those using the Sophia card which allows 16 step luminance.  I also altered DIN and Super 0 mode, so that the text in Antic 2 can be colored independently of the BG.

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