6560/6561 related oscilloscope and vectorscope images

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eslapion
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

joshuadenmark wrote:Why don't you post images here in our forum, ...
The previous version didn't allow that so I kept the bad habit.
... all the external image providers will disappear over the years, Denial will remain forever.
Nothing lasts forever but the earth and sky...
https://www.youtube.com/watch?v=tH2w6Oxx0kQ
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Kakemoms
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by Kakemoms »

eslapion wrote:
joshuadenmark wrote:Why don't you post images here in our forum, ...
The previous version didn't allow that so I kept the bad habit.
... all the external image providers will disappear over the years, Denial will remain forever.
Nothing lasts forever but the earth and sky...
https://www.youtube.com/watch?v=tH2w6Oxx0kQ
And Bill's Micro Soft? Which can also thank Peddle and his 6502 for their existence today. :D

Anyway, their onedrive works nicely with download links. I can put them on my page if you want.
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eslapion
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

Kakemoms wrote:Anyway, their onedrive works nicely with download links. I can put them on my page if you want.
Feel free to do as you please.

I left these captures for everyone to enjoy but that's as far as my stamina will allow. The rest is up to you.
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eslapion
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

In the end, I never managed to grab a vectorscope but I do have a considerably more powerful oscilloscope now.

If any captures are required, I'd be glad to deliver...

Lance ?

Sidenote: It will have to wait until I am back from Toronto...
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by joshuadenmark »

Great service :D thanks.
Kind regards, Peter.
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eslapion
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

Wow!... Postimage has done a fine mess of this thread. I don't think I have any backup of all the scope captures in here... :(
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lance.ewing
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by lance.ewing »

eslapion wrote:Wow!... Postimage has done a fine mess of this thread. I don't think I have any backup of all the scope captures in here... :(
The Wayback Machine (web.archive.org) appears to have crawled some of them, but not all:

http://web.archive.org/web/201609132004 ... 8lumas.png
http://web.archive.org/web/201609132004 ... easing.png
http://web.archive.org/web/201609132004 ... stluma.png
http://web.archive.org/web/201609132004 ... stluma.png
http://web.archive.org/web/201609132004 ... orange.png
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eslapion
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Re: 6560/6561 related oscilloscope and vectorscope images

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I have a much better oscilloscope with double the display resolution. Perhaps this thread could benefit... any specific request ?

I have a Tektronix TDS 3014B.
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

groepaz wrote:edit++: since your numbers differ significantly from what VICE currently uses, could you also tell the ripple range, and the exact VIC (as in the videochip) model?
Now that I have a more decent scope, I will try to get to that. I have already provided the details about the 6560 in a previous post.
well, ideally you make those measurements "blindly" anyway (like marko did) so the impendance of the monitor input is taken out of the equation.... make a small basic program that prints the coloured blocks (or even type them out blindly, which might be a bit error prone though) and then put a probe on pin3 of the VIC...
Actually, the common emitter configuration of video amplifiers used inside the VIC-20/VIC-20cr is really designed to have a load to operate properly. Normally, 75 Ohms impedance.

If the load isn't present, not enough current flows through the transistor and signal deformation occurs. Usually the amplitude becomes excessive and clipping occurs.
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

lance.ewing wrote:The Wayback Machine (web.archive.org) appears to have crawled some of them, but not all:
Hey thanks!

I fixed what I could...
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Re: 6560/6561 related oscilloscope and vectorscope images

Post by eslapion »

groepaz wrote:... since your numbers differ significantly from what VICE currently uses, could you also tell the ripple range, and the exact VIC (as in the videochip) model?
6560 ripple close study
6560 ripple close study
When the screen is turned full black (POKE36879,8), the 6560-101 has about 28mV ripple. This is in sync with the unused clock signal on pin 36.

Note: Channel 1 is Luma, Channel 2 is pin 36 and channel 3 is pin 35.

The amplitude has been normalized on the luma to have 1Vp-p between sync and white.

Added edit:
A more upclose study of the signal reveals the amplitude is even higher than I expected.
6560 ripple in higher details
6560 ripple in higher details
More like 40mV.
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