VIC interlaced video!!!

[bacon]

Trying it out right now on my PAL flat 128 with 1084s monitor. The default settings gave me a jittery picture without color. These settings for both even and odd fields work for me:
Cut raster = 300+0
Cut = 4 rasters

Looks really good!

[wte]

Marvelous, really great!
I've tried it today with my C128DCR and a 1901 monitor (PAL).
Parameters:
even: 300+0 / 44 / 4 ; cut cycle 44 is the best value to seperate the raster lines
odd: 299+0 / 40 / 4 ; cut cycle can vary +/- 14
Without change of "Reverse even/odd fields" (works with programm standard)

WTE

[hydrophilic]

Thanks for the feedback guys!  I'll mod the program so PAL default will use raster 300 with cycle 45 as a compromise between 44 (1901) and 46 (1084).  I'll get it uploaded tonight.

If you think the images are good now, just know they can be much better.  First these are standard bitmap images not FLI (higher color density). Second the pix were converted to Commodore format as two seperate images; an optimal method would consider both fields together for better dithering / more colors.

Unfortunately, I no longer own a small set I can hook up to my C128

It looks great on a large set!   I use a 36 inch JVC.  Now if I could get my hands (arms?) on a 54 inch set...

Edit
The moded version is now available.

Can I make a request of bacon and/or wte?  I am curious if it also works if you reduce the #cuts from 4 to 3 rasters and also increase the raster by 1.  In other words,
  301(even), 300(odd)
  cut 3(even), cut 3(odd)

If this works, it should be prefered, I think, because it would produce a frequency closer to 50Hz and would give the CPU an extra raster for processing (and it would be a border raster for 2MHz if desired).

[airship]

So... the method you describe on your web site for creating interlaced pix is rather convoluted and requires using a couple of different tools PLUS hex editing the file. Are you planning on coming up with something that a humble end-user (like me) could use? For free?

Ooh, ooh... and a slideshow program, too!

[wte]

@hydrophilic
1.  301(even), 300(odd) works with cut 4 (even/odd) but you have to change cut cycle to 26/50 (even/odd) for equidistant lines.
2.  There is no color (only grey) using 301(even), 300(odd) with cut 3 (even/odd) [cut cycle to 46/40 (even/odd) for equidistant lines].

How do you call your new graphic mode?
RIM for Real Interlace Mode and RIFLI for Real Interlace FLI?

WTE


I've made some picturs from my 1901 screen. I used my own hack of the program (see new menu point D. with "my" parameters).
If you want to have a look go to http://www.c128.net/album/interlace/index.htm
Sorry for the info text in pidgin english but if you are a native speaker please send me a better version.

[hydrophilic]

Thanks a ton for the feedback.  I really don't know why you'd loose color with cut 3... just goes to show I don't understand PAL interlace!  I love the screen shots on your web site!  I don't have a camera to take screen shots (and my video capture card doesn't grab both fields for snapshot pictures!), so would you mind if I used some of yours for my web page?  You would get credit of course.

I just call it Interlace mode, but if you want an acronym, RIM sounds good.  I like it because it sounds like REM.  For FLI mode, RIFLI is good too.  Really I don't care what its called, just that somebody uses it for something cool.  The entire reason I published it open source.

Airship, yes it is a pain to create images!  The hex editor is needed to add 1 stinking byte (the background color) to the end of the commodore file.  Why, why, why that program doesn't write the info is beyond me!  I've been contemplating an all-in-one conversion program, but the color optimization process gives me a headache just thinking about it!

I never intended to create a suite of application programs or games or anything.  I just wanted to see if Interlace is possible.  The idea had been bugging me for a few years so I broke down and bought a 128 just to try it out... so here I am today!

That said, I have a graphics program I wrote back in the day which is pretty cool if I may say so.  It was a combo BASIC+ML program like GEOpaint except it operated in multi-color mode.  It offered some unique tools too like polygon and polygram.  And multiple 'dimension' modes -- like for a circle, you could specify the the boundaries like GEOpaint / MSpaint OR you could specify the center and drag out to the desired radius (MSpaint et al PISS ME OFF for not offerning this mode).  If I ever finish my current project, I'll consider rehashing it to support Interlace pix.

[wte]

Thanks a ton for the feedback.  I really don't know why you'd loose color with cut 3... just goes to show I don't understand PAL interlace!  I love the screen shots on your web site!  I don't have a camera to take screen shots (and my video capture card doesn't grab both fields for snapshot pictures!), so would you mind if I used some of yours for my web page?  You would get credit of course.

Hi!
It's your program and hard work, so feel free to use the pix. I used a simple digital camera an a tripod took 20 or 30 pix and used the best one

regards WTE

[hydrophilic]

Thanks for the pix.  Although proud to have accomplished my goal, I would not call it work.  Or maybe, I wish all my work was as fun as this project.

I noticed in the FLI text screen that the top of 'Zero' is cut off.  I guess this is just hard to see because of the bright border?  I also noticed the PAL screen is very wide compared to NTSC.  For NTSC, the VIC display is close to the TV aspect ratio of 4:3 but it looks like PAL is about 7:4 (almost 2:1).  Interesting...

[wte]

I noticed in the FLI text screen that the top of 'Zero' is cut off.  I guess this is just hard to see because of the bright border?

Yes it is the bright border. All lines are visible. I've changend the border color, shot a new pic and added it on my site.
Direct link: http://www.c128.net/album/interlace/10_textdemo2.jpg

[smf]

If this mode had been discovered back in the day (along with the hi-res graphics capabilities of the 64K VDC), the C128 would have remained a viable machine for years, and the C65 would have just been the first of many successors.

It's that good.

I think it's great that this has been discovered and I don't want to diminish the achievment. However I disagree with your conclusion.

The 128's problem was that not only was it never viable, it's fate was sealed by the amiga(*)

The 64 managed to last until the early 90's because it was dirt cheap. Making it better would made it more expensive. You could argue that a few more weeks here and there could have extended it's life alot more, the serial bus was a joke. Trying to fix it in the 128 was too late and too expensive.

The only way the 128 could have lasted over the 64 is if the vic 20 was more like the 64 and the 128 was more like the 64. Then ditch the 64 completely. The 128 should have had an 80 column vic that could output analogue rgb, in fact the 128 should have been more like what the 65 was going to be ( but better compatibility ). No z80, no vdc, less rom & it might have worked.

However without the vic20 and c64 as they were and when they were, the market would have been a completely different place and commodore might not have had the success they did. Commodore would also have had to pass on the amiga, which could have changed everything.

I guess, in summary, it was a hell of a ride and even today you can have some fun with it.

* yes I understand the irony of this statement, bearing in mind what site it's posted on. I couldn't afford either when they launched, but the amiga was better and about the same price to build. I bought an a500 in 89 when I could afford it.