C-Sync on 520ST C070115 REV.2B

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exxos
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Re: C-Sync on 520ST C070115 REV.2B

Post by exxos » Sat Aug 31, 2019 12:54 am

Normally odd things like that are down to the monitor not being able to displays the video modes correctly. Its also more problematical because the video modes are not "to spec". So monitors which state they support the resolutions still may not work.

As you can display high res fine, them its unlikely to be a fault with the shifter or glue. Though these machines also have their own quirks. It may be better to find a more modern STFM machine as they have composite output anyway.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: C-Sync on 520ST C070115 REV.2B

Post by spbmlb10 » Sat Aug 31, 2019 1:51 am

Thanks for your time mate maybe it’s time I start looking for a replacement. I just didnt want to give up hope as it has such a awesome 4mb ram upgrade.

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Re: C-Sync on 520ST C070115 REV.2B

Post by exxos » Sat Aug 31, 2019 8:26 am

The problem is that you don't know which is at fault, the ST, the monitor, or both. There are monitors listed which are known to work. Though you still don't know if the ST has a issue or not. You need to rule things out.

IMO. Getting a stfm is the way to go, then you can try your monitor to see if the issue is still there or not..
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: C-Sync on 520ST C070115 REV.2B

Post by spbmlb10 » Thu Sep 05, 2019 11:27 am

Sorry I actually thought I had mentioned this, I had a 1040 STFM I sold around two and a half months ago, I kept the 520 due to the 4mb upgrade. I guess if I do buy another I’ll probably look for a STE. Anyway the 1040 worked fine on my C64 monitor I never did try it on my OSSC or lcd as I never had the adapter then but there was no problems with it displaying. The 520st would never sync as it doesn’t have a modulator or anything coming from pin 2. It used to just scroll on the monitor until I built a sync combiner circuit inline on a cable I had. Then it displayed exactly as in the pictures above. I then removed the cable and tried adding the components to build the sync circuit onboard as show in this post above then received the ST2VGA and the exact same issue in the display but I could now test Low res mono and that displayed fine. I realised I never mentioned it. I think I thought I did because I had posted on Facebook around the same time. I feel like a knob to be honest maybe I was half pissed when I initially posted.

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Re: C-Sync on 520ST C070115 REV.2B

Post by spbmlb10 » Thu Sep 05, 2019 11:48 am

spbmlb10 wrote:
Sun Jul 07, 2019 9:04 am
Ok I tried something else, I realised the 1084s has v and h sync. Not sure why I didn’t try it sooner I have this picture coming up once creating a cable for v and h sync. I connected the c-sync circuit I created to correct c-sync pin later as well to see if things would change and nothing changed.

What I’m getting is the image now not rolling but i cannot adjust it any more to the left with monitor adjustment. Had no issue with 1080 on same monitor.87756D79-F037-4F19-BB25-0DB17FA652F9.jpeg I’m also getting some type of jumping. Cannot attach video very hard to see in it anyway. The top and bottom of screen are moving a few mm down then back up in a timed pattern it’s less than a second. I don’t know any other way to describe it. Refresh rate related? Or sync? I’m not sure.

Lol 😂 seriously this is taking some time to sort out but I’ve invested that much time now I’ve got to get it right. Any more ideas?
Hi Exxos it looks like I did mention it but I wrote 1080 instead of 1040 maybe that’s the confusion I was thinking of the monitor obviously. So I have tested it on a 1040STFM without display issues.

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Re: C-Sync on 520ST C070115 REV.2B

Post by exxos » Thu Sep 05, 2019 2:15 pm

Probably best still getting a STFM as I doubt you will have issues with outputs. But also you have a working machine to compare signals on your ST to see if anything sticks out as being wrong anywhere.
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

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Re: C-Sync on 520ST C070115 REV.2B

Post by mrbombermillzy » Thu Sep 05, 2019 7:42 pm

I know its a bit out on a limb, but Ive got an Acorn AK30 monitor (which is basically an Amiga 1084) with CSYNC input.

I didnt have the correct lead for it or time to build one, but plugged in an STFM into it. According to the schematics, I had Red connected and one of the syncs (Vertical IIRC). It displayed correctly, aspect wise (not like the problem you are having), but would roll when the screen changed or something moved. This is a typical response from not having a HSYNC connected.

So, it looks like you have some other issue going on here. Like Chris says, maybe get yourself a STFM/E and check if its different.

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Re: C-Sync on 520ST C070115 REV.2B

Post by exxos » Thu Sep 05, 2019 7:46 pm

wow sync on red.. now that is oldskool ;)
4MB STFM 1.44 FD- VELOCE+ 020 STE - 4MB STE 32MHz - STFM 16MHz - STM - MEGA ST - Falcon 030 CT60 - Atari 2600 - Atari 7800 - Gigafile - SD Floppy Emulator - PeST - HxC - CosmosEx - Ultrasatan - various clutter

https://www.exxoshost.co.uk/atari/ All my hardware guides - mods - games - STOS
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