liqmat wrote on 2021-10-26, 18:11:

I don't have any of that anymore, but this is the model. […]
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Jo22 wrote on 2021-10-26, 17:48:

liqmat wrote on 2021-10-13, 20:51:

These photos are back in 2015 when I was restoring a slew of C64 and VIC-20s. As you can see, the image on that LCD TV is crystal clear with no modifications made on the Commodore systems themselves. Used a composite A/V cable I bought on Ebay.

c64_basic.jpgc64-vic20_restoration.jpg

Um, does that screen use a scaler maybe?
On my b/w tv from the 70s there is noise, with vertical stripes (using the stock RF modulator box). 🙁

I don't have any of that anymore, but this is the model.

Paired with one of these.

It was a crystal clean image.

Ah, I see. Thanks for the links! 😀

I did the modification of removing C6 (2x 68pf ?).
The image turned grayscale, but the vertical lines remained.
Could it be that the VIC II is the real meanie here?

I've checked both via RCA (b/w CRT tv via RF) and the AV/Composite cable (4k smart TV with SCART input)..

From what I can tell, there's not much difference. 😞
The picture of the old televisor isn't that much different, except for some slight noise due to the method of signal transportation (RF).
If I do increase contrast, it goes away, but also increases these nasty vertical lines.

Edit: Found some more information.
Apparently, the stripes are always there unless a mod is installed (LumaFix64 etc).
Also, the original C64 is more affected than, say, the C64C.

http://hitmen.c02.at/temp/palstuff
https://www.obliterator918.com/my-quest-for-a … display-for-it/

Edit: Just found another interesting article/blog entry about the LumaFix64..
It seems that these C64 video issues can't be completely cured.
Also, the issues are apparent in different intensity, depending on the VIC II models (beware, some need 12v!).
https://www.breadbox64.com/blog/the-lumafix64-mod/

Here's another option to clean up the C64's video:
https://www.etsy.com/de/shop/JaystoniansRetroShop

Jan Beta made a video about it:
https://www.youtube.com/watch?v=_xM0HnwY8vY

I did the following on my PAL breadbin (Rev. 250407), to get rid of most of the video signal interferance and noise.

Recapped the entire board and replaced both voltage regulators. Then I bought an 6569 R5 VIC-II chip, as it delivers the cleanest image quality. Some say revision 3, but again it differs from chip to chip. I have just had more luck with an R5 than R3. Cable is important on the C64 as well, as the C64 have one of the worst video signal quality of all vintage 8-bit's. Amstrad and Atari have way better signal quality. However the C64 have room and option for improvements. Hence I bought a cable from RetroComputerShack.

On my SixtyClone 250466 machine, I have gone for an VIC-II 6569 R5 again, and I tried one of the modern RF-Modulator replacements, however I found that a NOS and never used original modulator delivered a better image quality. On my ATX-64 build, I have found that disabling the composit output and using a 8565-R2 VIC-II would give a better image quality.

For cables, then I have nearly eliminated vertical lines and the rainbow effect. By using a RetroComputerShack branded S-Video cable and a Retrotink2X-Mini upscaler on a Samsung syncmaster 1080P television. I am near emulator quality yet still maintaining the analog feel of it all.

You can check out my two builds (SixtyClone and ATX64) on my YouTube channel. But beware. I speak horrible English.

My c64c is really nice with the luma fix installed using svideo on a retrotink scalier. its a very nice clean image but my breadbin is cursed with the red colour in the jail bars at this stage im just going to look for another fully working motherboard and put it in my case as my breadbin case is mint. i am no good at these mods or soldering and dont know any vintage computer repair shops in Australia that i could send it to

Jo22 wrote on 2021-10-26, 17:48:

On my b/w tv from the 70s there is noise, with vertical stripes (using the stock RF modulator box). 🙁

I used to see that on other 8 bits, when the focus was set super sharp, if you knocked it very slightly off focus it went away.

When I first got my C64 a number of years ago I was very disappointed with the video output and made a modification that cleared up most of the problems :

Luma alone :

Chroma+Luma :

The mod is more or less just buffers right at luma and chroma outputs of VIC II + some capacitors peppered around the power rails. AV out I have modified to my own standard so I can use single cable with all my machines.

Yup.... Stock C64 have a shitty image quality, unless you get an original CRT that are specifically designed for it, then you need to do mod's. I can only repeat that if you have a longboard, then you need to get a Rev3 or Rev5 VIC-II and have something like a Retrotink or one of them component upgrade boards. That is, if you are going the LCD route. Another thing to look forward to, is the Kawari board. Adrian Black have this (not exactly new) video about it on YouTube.

Yeah.... These vintage computer areas, can be expensive....

Hi All I know this is an old thread but only recently got around to playing with my breadbin once more to try and fix these video issues i did all the above mods in Adrian Black's Vid.
i also got another lumafix but have not used it as it did not fix the jail bar lines at all. this is the best pic i can get out of this computer as any other mods are well outside my field of expertise.
I Am still not happy with this computer i may be looking to buy another breadbin. at the moment i am using my commodore c64c and that has a beautiful pic.
thankyou all for your help on this matter.

vkcpolice wrote on 2023-11-03, 08:23:

Hi All I know this is an old thread but only recently got around to playing with my breadbin once more to try and fix these vide […]
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Hi All I know this is an old thread but only recently got around to playing with my breadbin once more to try and fix these video issues i did all the above mods in Adrian Black's Vid.
i also got another lumafix but have not used it as it did not fix the jail bar lines at all. this is the best pic i can get out of this computer as any other mods are well outside my field of expertise.
I Am still not happy with this computer i may be looking to buy another breadbin. at the moment i am using my commodore c64c and that has a beautiful pic.
thankyou all for your help on this matter.

I have several C64s and their image quality differs a lot depending on the revision of the motherboard. VIC-II chips have some variances and the condition of the tuner also affects the image quality as the video output is provided by it even if you don't use the RF tuner. Image artefacts are also much more evident in LCD screens, but differences are also very noticeable in a good CRT and using the "pseudo" s-video C64 can provide (I use Sony PVM and s-video exclusively).

I don't have any C64 250469 shortboards (I have two C64cs, but other came with 466 and other with 407), but in my personal experience for longboards 425 and 466 revisions are equally good and provide really good image quality out of the box at least with my setup: sharp image, good color reproduction and no noticeable jailbars. It should be no surprise as those boards have essentially the same layout and use the newer clock gen circuitry and the only major difference is the memory layout used. However, I have two 407s and both have equally bad IQ out of the box. 407 has clearly noisier and softer image and it has jailbars with certain colors even on CRT/s-video.

I did tuner replacements and installed lumafixes to both of those, which together improved the IQ at least close to the level of 425/466 boards. I assumed that the major reason for the IQ problems with 407 (and possibly with earlier boards too) is the noise from clock circuitry near the VIC-II chip, but when I got to beta testing a clock circuitry replacement module, which practically disables the original clock circuit with more or less modern one chip solution, there was pretty much no change in the IQ. This leads me to think that there is something else in the board layout where some signal traces cause interference to video output of the system. In this era, mainboards of these micros weren't if not at all, then at least not much optimized for interference as such interference wasn't a significant problem when they were used with the typical output method (RF tuner) and cheap and poor quality TV sets of the day: IQ was shitty due to other factors and issues caused by the video output circuitry were practically hidden and secondary because of those. Nowadays people want to have the best possible IQ with CRTs or use LCDs and connect the computer using composite or s-video cables, which now highlights the noise issues generated by the motherboard.

Watched this just another day.

https://youtu.be/SBgo8oGFung?si=cIUkbn1EkN-Tqb5B

Thanks CharlieFoxtrot interesting read it seem all c64s are like this and all you can do is improve the video signal but it will never be perfect. im not sure what causes the jail bars but its obviously how the computer writes the image to the screen. that sort of stuff is way beyond me. i guess i will just have to accept this is how they are and even if i buy more they could be better or worse than the one i have.
my c64c has a better video output barley visible jailbars but the signal is also not as sharp and thats probably what makes the jailbars not so visible.
i also heard that the different scalier you use also make a huge difference i was using a retrotink but that show the jailbars to much so i went back to my small lcd tvs inbuilt s video input

thanks Kekkula looks interesting maybe one day but im not a fan of adding extra computers like the pi to these old computers i like everything to be original