Amiga.org

Amiga.org (http://www.amiga.org/forums/index.php)
-   Amiga Hardware Issues and discussion (http://www.amiga.org/forums/forumdisplay.php?f=13)
-   -   Commodore 1081 PAL screen jitter oddity (http://www.amiga.org/forums/showthread.php?t=59125)

AF-Domains.net 09-14-2011 03:43 PM

Commodore 1081 PAL screen jitter oddity
 
Greetings,

Not entirely sure whether this is down to a possible fault that was fixed in a later design or not..

While using the 1081 to watch a PAL DVD (widescreen format usually), the screen will jitter intermittently vertically.

Unable to provide any photos at this time that may help describe this.

This does not surface when viewing NTSC DVDs.

This oddity does not seem to surface at all on a spare 1084s.

Anyone else encountered anything like this?

What could be a possible cause?

save2600 09-14-2011 05:11 PM

Re: Commodore 1081 PAL screen jitter oddity
 
My various model 1084's and 1084s's ALL produce a consistent high-speed jitter when viewing PAL on the 60hz American electrical grid. Are you referring to this natural phenomenon?

AF-Domains.net 09-14-2011 05:24 PM

Re: Commodore 1081 PAL screen jitter oddity
 
Greetings,

I probably should've clarified there.

I'm located in the UK, 50Hz here.

AF-Domains.net 11-10-2011 10:23 PM

Re: Commodore 1081 PAL screen jitter oddity
 
1 Attachment(s)
Although it has been a while, still haven't been able to find a possible cause as of yet.

I've however attached a photograph to display what occurs.

I apologise if my general terminology was completely off.

Zac67 11-11-2011 12:31 AM

Re: Commodore 1081 PAL screen jitter oddity
 
You've checked v-hold, haven't you?

CritAnime 11-11-2011 01:55 AM

Re: Commodore 1081 PAL screen jitter oddity
 
I have seen something like this before. I dunno if its the same thing but When I tried watching some DVD's on my PC I got serious interlacing issues which was fixed after altering some settings in Video Lan. Which produced an effect much like yours. Now I don't know how to remedy this for you. But it might be a potential cause of this. So I would check to see what the settings are.

Just a suggestion.

AF-Domains.net 11-11-2011 08:10 AM

Re: Commodore 1081 PAL screen jitter oddity
 
Greetings,

I've checked the V-Hold, that appears to be set correctly.

This also tends to be intermittent.

The image is stable during certain scenes, while appearing to almost roll vertically on others.

I have a 1084S that doesn't seem to be afflicted by this, though it's currently in for repair.

Framiga 11-11-2011 08:43 AM

Re: Commodore 1081 PAL screen jitter oddity
 
if you have already tried playing a bit with the "V-Height" knob in the rear panel, probably is the analogic DVD copy protection that makes some old monitors (in need for some face lifting), acting like yours.

Zac67 11-11-2011 11:12 AM

Re: Commodore 1081 PAL screen jitter oddity
 
Yes, that Macrovision crap may well be a problem... There are video stabilizers that'll remove the problem. Bought a "Video Boy" switcher+stabilizer years ago for some 5€ or so.

AF-Domains.net 11-11-2011 05:13 PM

Re: Commodore 1081 PAL screen jitter oddity
 
At the present time, the DVD player is connected to the 1081 using the Scart socket (RGB mode rather than CVBS, on the faint chance there'd be some improvement), no change to the vertical frame roll.

Regarding a video stabilizer, will attempt to get ahold of one to see if that does the job.

With any luck it does.

More or less out of ideas as to what else could be done, short of replacing the monitor entirely.

AF-Domains.net 11-12-2011 10:38 AM

Re: Commodore 1081 PAL screen jitter oddity
 
Unfortunately, a video stabilizer had no noticeable effect.

Was hooked up correctly, but still the same picture jump effect on PAL depending on the scene.


All times are GMT -6. The time now is 08:07 AM.

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.

Amiga.org & logo copyright © 2014 A-EON Technology Ltd
The forums were originally created by Wayne Hunt