Indivision ECS V2 ghosting

Quote from angelvaldes

do you know if the icomp acceleratos boards that you can add to the ACA500Plus would fit on the large gismo?

And how do u understand the german?

Thanks¡

scroll down on that site and you see the English text 😲

All accelerators from iComp would fit

Quote from Phil

Connected with the VGA cable to the BenQ BL702a, that MK3 is a dream! Jens made it too good 😀

yeah, digital out combined with the tool from ECS V2 is probably why. Honestly, I wish he went with digital out on the ECS V2 and TC64 V2. We would have had no ghosting problems. I just ordered some ferrite beads from China now. At least, when I have the ECS V2 in my A600 and VGA connector secured to the motherboard shielding it's not too bad.

We'll see if the ferrite beads will improve this further.

Quote from Netizensmith

No ghosting on my version. It’s in an A2000 and connected to a Benq widescreen 1080p lcd.

I wonder if it's because the VGA output plug is secured to a metal bracket that sits against the chassi. Also considering the A2000 has a huge chassi. Equals to huge groundplane. Also, probably the VGA cable routes quite a distance from CPU/CPU accelerator.

I now have it in an A600. Still no ghosting

Quote from Netizensmith

I now have it in an A600. Still no ghosting

Have you tried the DOS demo?

Also, you have the VGA port secured to the RF shield in place of the TV modulator? Also, you have an accelerator in your A600? And have you tried it in an A500?

The ECS-V2 VGA onboard cable is flat cable, non shielded VGA cable. Having very ghosting problem with ECS-V2 and changing the monitor’s cable I see huge improved (i have little ghosting now). Maybe the onboard ECS-V2 VGA cable replacing it with standard VGA shielded cable eliminates the ghosting.

Quote from Phil

All accelerators from iComp would fit

ACA1240/1260 and ACA1234 will be longer - one reason why I have always attempted to keep people from "designing" a case without asking what sizes we may do in the future.

Quote from mbruines197703

Hmm, isnt it so that every pin on vga has its own ground pin..

Tried the extra ground (you never now) but no effect on my a500+

On my A600s it's a very noticeable difference if I secure VGA out port to the RF shielding VS having the plug and cable loose, and only using the ground wire from Indivision ECS/ECS V2 to motherboard ground. Also, in my A500 + there was a noticeable difference when I moved the ground from Indivision/motherboard connection to indivision VGA plug. You have to test with something that shows the ghosting properly. Should be a difference. It will not get completely rid of the ghosting but it's an improvement. As said, A600 was the best scenario. Next I will try to bridge a groundwire directly between the A500 RF shielding and the plug. Maybe securing one end of the wire to the nut on the RGB port and the other end to the VGA connector.

The VGA connector has grounding yes, but the wires in the flat cable are thin and not shielded. And they go via the Indivision.

Edit: And of course, it goes without saying, use a good VGA cable with ferrites in both ends. Even if it has ferrites in both ends it can still be bad. I have tested many cables and picked the best. A bad VGA cable will introduce even more ghosting. Again, goes without saying.

Quote from turrican9

We are talking about these 3 transistors?

What you marked in the picture are the three clamping diodes that catch over- and under voltage on the RGB signals. The driver transistors are on the other side, but since the RF-grade transistors I intend to use have a different working spot, some additional parts need to be used. Once again, it's not as simple as just exchanging parts, but the whole output stage must be re-designed.

Quote from Jens

What you marked in the picture are the three clamping diodes that catch over- and under voltage on the RGB signals. The driver transistors are on the other side, but since the RF-grade transistors I intend to use have a different working spot, some additional parts need to be used. Once again, it's not as simple as just exchanging parts, but the whole output stage must be re-designed.

I wonder what would happen if one cut away the plug from one end of a quality VGA cable that has ferrite cores in both ends and soldered it directly to the flatplug connector on the indivision card? After all, the flat vga cable that comes with the indivision must pick up some noise and could be part of the reason for ghosting?

Quote from turrican9

I wonder what would happen if one cut away the plug from one end of a quality VGA cable that has ferrite cores in both ends and soldered it directly to the flatplug connector on the indivision card? After all, the flat vga cable that comes with the indivision must pick up some noise and could be part of the reason for ghosting?

No, it's not part of the ghosting at all. The pinout is carefully chosen so that "every other" line is AGND. This is not equivalent, but close to a coax connection. What we already found here in the thread is that proper ground connection is a large part of the equation, so if you want to improve something, go with the suggestion of mounting the VGA connector on the RF shield.

Quote from Jens

No, it's not part of the ghosting at all. The pinout is carefully chosen so that "every other" line is AGND. This is not equivalent, but close to a coax connection. What we already found here in the thread is that proper ground connection is a large part of the equation, so if you want to improve something, go with the suggestion of mounting the VGA connector on the RF shield.

And adding ferrite cores to the flat cable would not help improve it further?

Edit: Should think that would improve it further because I at least in the case of the Indi ECS V1 (Think I've seen it with ECS V2 aswell) have observed the flat cable picking up noise from accelerators in A600s and ACA 500 + accelerator in A500s. In the case of the A600s, routing the flat vga cable differently past the accelerators fixed the noise issue. So I would guess ferrite cores should help somewhat

Quote from turrican9

And adding ferrite cores to the flat cable would not help improve it further?

Ferrite cores would filter very high frequencies that the monitor doesn't sample anyway. And such high frequencies are not on the signal at all. That was the whole goal of designing the circuit that way

"pick up noise" is probably not what the cable does - note that especially the A600 suffers from it's 2-layer board and accelerators are usually only grounded through the 68-pin socket. I did provide the extra screw with the ACA630 and the Rev.2 of the ACA620, but I still (after both are not available any more) need to explain that it's not a pure mounting screw, but also a grounding screw that helps stability of the whole system.

So here we go again: Grounding. Make sure to have not only the GND cable of Indivision mounted, but also the shield tightened down with all screws. Only this will give the 2-layer boards the shortest path to GND.

Quote from Jens

Ferrite cores would filter very high frequencies that the monitor doesn't sample anyway. And such high frequencies are not on the signal at all. That was the whole goal of designing the circuit that way

"pick up noise" is probably not what the cable does - note that especially the A600 suffers from it's 2-layer board and accelerators are usually only grounded through the 68-pin socket. I did provide the extra screw with the ACA630 and the Rev.2 of the ACA620, but I still (after both are not available any more) need to explain that it's not a pure mounting screw, but also a grounding screw that helps stability of the whole system.

So here we go again: Grounding. Make sure to have not only the GND cable of Indivision mounted, but also the shield tightened down with all screws. Only this will give the 2-layer boards the shortest path to GND.

I have been using the grounding screws with my ACA 620 for years. Without them I had issues. I have also been using the grounding cable that came with my indivision ECS/ECS V2. Yet, routing the flat VGA cable in different ways around, over or on the side of the accelerator could affect the picture. So clearly the cable picked up noise.

Ghosting on both the ECS V1 and V2 is worse in the A500. Probably because I have no place to secure the VGA port to the shielding properly, like with my A600s, I have them screwed against the RF shielding in place of my RF modulator which has been removed.

Been experimenting with ECS V2 in my A500 plus now. Put a grounding cable from one of the nuts on the RGB port (which is screwed against the shielding) and to the Indivision VGA port nut. This reduced ghosting a tiny bit. Ghosting is still horrible. Then I unscrewed the plastic housing on the VGA plug itself and held the shielding against the A500 main shielding. This made a little bit more difference to the ghosting. However, the ghosting is still quite bad.

ECS V1 also has quite bad ghosting in my A500s but made more of a difference using a grounding cable to the VGA plug shielding VS ECS V2.

ECS V1 is almost ghosting free in my A600s when VGA port is secured against the RF shielding. ECS V2 still has very noticeable ghosting in this same scenario, but much better VS having it in my A500s.

Quote from turrican9

ECS V1 also has quite bad ghosting in my A500s but made more of a difference using a grounding cable to the VGA plug shielding

I have literally never had any complaints about Indivision ECS V1 having ghosting - only when the V2 was out, some people popped up claiming that it was not OK on V1 either - after almost ten years of availability of the product. The true reason may be that the input stage of those Samsung-based monitors has not been available back then.

However, you confirming that there's a noticable difference between A500 and A600 means that grounding and power supply plays a major role. In other words: Even after the patch-PCB is available, you may still see a difference because of the grounding/PSU difference of your computers.

Quote from Jens

I have literally never had any complaints about Indivision ECS V1 having ghosting - only when the V2 was out, some people popped up claiming that it was not OK on V1 either - after almost ten years of availability of the product. The true reason may be that the input stage of those Samsung-based monitors has not been available back then.

However, you confirming that there's a noticable difference between A500 and A600 means that grounding and power supply plays a major role. In other words: Even after the patch-PCB is available, you may still see a difference because of the grounding/PSU difference of your computers.

I swapped ECS V1 over into my A500 plus setup again. installed a grounding wire from the rf shield to the VGA connector. Ghosting is very visible depening on the colours. Grounding wire helped a bit. This same ECS V1 has very little visible ghosting in my A600 when VGA connector secured to RF shield.

ECS V2 is now in that A600 with the VGA connector secured to the RF shield. Ghosting is very visible, but improved quite a bit VS having it in my A500.

I've tried all kinds of LCD monitors and LCD TVs. ranging from 2004 up until more modern ones. They all show a very similar/identical beavior with regards to the ghosting. My PSUs are various recapped commodore CPUs.

Sadly I do not have an Amiga 2000 to try ECS V1 and V2 on. I would have liked to try that to see how much a difference it would make if I secured the VGA connector to the huge chassi of the A2000.

The best picture I got was an extra ground wire from the VGA plug to my ACA500+.

The ghosting is almost gone, the smearing is a lot better now but it’s still visible by moving objects with a blue, purple or green background.

Quote from Phil

The best picture I got was an extra ground wire from the VGA plug to my ACA500+.

The ghosting is almost gone, the smearing is a lot better now but it’s still visible by moving objects with a blue, purple or green background.

Interesting, so this made a much bigger difference for you VS having groundwire from VGA plug to motherboard or RF shield?

My Indivision is in a checkmate case and the ghosting is not that annoying. I wonder if grounding the VGA connector on the TC64 would help reducing the ghosting there.