Scanline Generator T-SLG

[bencao74]

More the output stages of the connected picture sources to be exact, means scalers or consoles. For me I like to have some sort of security in my designs. So if I go with that TTL based ICs plus potis against GND i would just add some base loads. It´s of course possible to save some cents here and to reduce to design plus PCB space. But from my point it isn't worth to save money here. Since I guess this is a prototype run a protection can easily be added. Perhaps this will happen, perhaps not.

edit : Have in mind that this is only a technical advice. I hope that nobody takes this hint personal. If this would be my design I would add such a protection like done at SLG SCART. I do not have the time, mood or anything else to aggravate against anybody. This post is only motivated from my technical point of view and understanding.

[toodles]

Bencao, your let me see if I got this right.
You feel that setting the RGB lines to ground is somehow dangerous in a situation you can only describe as 'something you've come across' with no greater detail, should be using some protection that you cannot specify nor give an example of, and that the SLG3000 is safe in this hypothetical situation because you're using analog switches to connect the RGB lines to ground instead of an open drain logic chip I use in mine. Lastly, that you're very serious about this based on your knowledge of video signals.

Because I gotta admit, this is pretty weak. If you'd rather the book knowledge be brought to show how you're either dishonest or incompetent, I'd be happy to help. But maybe I'm mistaken and this is poor joke on your part. If so, I'd appreciate it if you said so now.

[fagin]

Guys,
I or anybody else is not interested in anyones bitch slapping session, but if someone says or insinuates that a device could potentially cause damage to a source, I think we would all be interested to hear the facts - plain and simply.

[toodles]

The problem with the HDFURY2 output working effectively with the SLG is the sync polarity, plain and simple.

HDFURY or HDFURY gamer edition output the correct sync and work. HDFURY3 will output the correct sync if you change the dip sw setting on the HD3 to suit.

If this device relies on a specific polarity, the issue will be the same.

If the only difference is the sync polarity (short high pulse on HSYNC, at rest is low, rather than the more common short low pulse on HSYNC and at rest is high) then that wouldn't cause the problems described, for either scanline generator. Both flip flops only care about a single transition, from high or low, or perhaps from low to high. It doesn't care about the other opposite transition. Whether the HSYNC was a short high pulse or a short low pulse, there'd only be one of the triggering transitions per horizontal line. (I guess this is the long way of saying that niether device is relying on a specific polarity of the HSYNC.)

I still believe based on the description that it's a problem with an odd number of HSYNC pulses per frame. If this schematic is accurate:
http://nfggames.com/forum2/index.php?to ... 0#msg30650
, then there is no reset of the flip flop during the VSYNC; it will alternate every HSYNC pulse. If it didn't reset on VSYNC, and the source was giving an odd number of HSYNCs per frame, then on the first frame it would darken lines 1, 3, 5, 7..... and the next frame would be 2, 4, 6, 8.... and then 1, 3, 5, 7..... on an on, alternated each frame. Mine resets on VSYNC.

I'll be borrowing SGGG2's HD Fury 2 shortly, and will be able to give a better answer once I get it under an oscope, but Im more and more confident that this is the problem seen with the HD Fury 2 + SLG3000, and that mine will work fine with it without modification. I'll definitely post up when I have it in front of me.

[fagin]

It's the same problem using a Cinemateq Line Doubler prior to the SLG. I have personally built an invertor and it fixed the problem.

On the HDFURY3 it does the same as the HDFURY2.... Until you flip the sync polarity via the dip sw settings on the HDF3.

[bencao74]

Bencao, your let me see if I got this right.
You feel that setting the RGB lines to ground is somehow dangerous in a situation you can only describe as 'something you've come across' with no greater detail, should be using some protection that you cannot specify nor give an example of, and that the SLG3000 is safe in this hypothetical situation because you're using analog switches to connect the RGB lines to ground instead of an open drain logic chip I use in mine. Lastly, that you're very serious about this based on your knowledge of video signals.

Because I gotta admit, this is pretty weak. If you'd rather the book knowledge be brought to show how you're either dishonest or incompetent, I'd be happy to help. But maybe I'm mistaken and this is poor joke on your part. If so, I'd appreciate it if you said so now.

Toodles, keep up your work as I do mine. What I don't really get is why you call me dishonest, imcompetent or I don't know. I`m sure you can do your technical arguments without that. Just try.

SLG3000 does not connect the RGB lines to GND. Using analogue parts gives me a complete other design space and choices, so I do not need to ground the RGB lines.

[StarCreator]

If this would be my design I would add such a protection like done at SLG SCART.

Can you elaborate on what kind of protection is implemented on the SLG SCART? Would it be something that could be implemented on the T-SLG?

[toodles]

It's the same problem using a Cinemateq Line Doubler prior to the SLG. I have personally built an invertor and it fixed the problem.

On the HDFURY3 it does the same as the HDFURY2.... Until you flip the sync polarity via the dip sw settings on the HDF3.

That's really weird. I'll definitely let you know what I find out when I get the HD Fury 2 in.

I`m sure you can do your technical arguments without that. Just try.

As you wish.

SLG3000 does not connect the RGB lines to GND. Using analogue parts gives me a complete other design space and choices, so I do not need to ground the RGB lines.

Yes, actually it does. The analog switch directly connects the RGB lines to the color return; guess what, that's ground. Check with the VGA-1P; each color return is directly connected to each other and GND. Check you Dreamcast VGA box. Check your computer's VGA port. Check your monitor's VGA port. Check your TV's VGA port. I haven't personally tested an XRGB, but I'd bet $2 per model that they are the same as well. Check them all. Set your multimeter to check for continuity, and you'll see that the red return, green return, blue return, all are directly connected to ground on your equipment that transmits, and also on the equipment that receives, VGA signals.

What's mind boggling ironic about this? I use a tri-state buffer effectively as an open drain buffer. It doesn't 'connect to ground', it's a 0v voltage source. There's no continuity to ground, unlike the analog switches. The SLG3000 does more to directly connect the RGB lines to ground than the T-SLG by using the analog switches. *shrug* It doesnt matter, and it doesn't hurt anything, but man that's some irony.

If this would be my design I would add such a protection like done at SLG SCART.

Can you elaborate on what kind of protection is implemented on the SLG SCART? Would it be something that could be implemented on the T-SLG?

Oh I could easily swap out the tri-state buffer for an analog switch chip if there were any legitimate need to.

[Overkill]

HDFURY or HDFURY gamer edition output the correct sync and work. HDFURY3 will output the correct sync if you change the dip sw setting on the HD3 to suit.

I will have to correct you, as the HD Fury gamer edition don't work with the SLG 3000. It was my first choice when i bought the SLG 3000, but unfortunately it don't work. My setup have the HD Fury 3 now.

[toodles]

Does the HD Fury 2 (and I guess the HD Fury 3 with the DIP in non-invert position) also invert the vsync, so its low at rest and high on vsync? If so, I could definitely see problems.

[Masa]

Did some tests with an ASUS VH236H
Xbox 360 el cheapo vga cable
Resolution - Scanlines
640 x 480 - Yes
848 x 480 - No
1024 x 768 - Yes
1280 x 720 - No
1280 x 1024 - No
1360 x 786 - No
1440 x 900 - No *screen flicker in wide*
1680 x 1050 - No *screen flicker in wide*
1920 x 1080 - Yes *set to this mode, turn off 360, turn on 360, it works. weird*

Ebay scalers
GBS 8200 v4.0 (2010.10.29)
all resolutions worked after hitting the sw button after doing a switch, however if running any video it will only work on 640 x 480 and 1024 x 768 modes. On 800 x 600 and 1360 x 786 it either has no scanlines *normal* or makes the image unstable *wide*. This seems to be the case for all three inputs types.

GBS 8220 V3.0 (2010.12.20)
same as the gbs 8200, worked better with the middle vga port.

DC VGABOX (DC Super VGA BOX (DC2000/February 2008 KENT) *on bottom* XK-DC 2000)
Causes "VGA no signal", however running it though one of the ebay scalers causes it to work, very weird.

[toodles]

Did some tests with an ASUS VH236H
Xbox 360 el cheapo vga cable
Resolution - Scanlines
640 x 480 - Yes
848 x 480 - No
1024 x 768 - Yes
1280 x 720 - No
1280 x 1024 - No
1360 x 786 - No
1440 x 900 - No *screen flicker in wide*
1680 x 1050 - No *screen flicker in wide*
1920 x 1080 - Yes *set to this mode, turn off 360, turn on 360, it works. weird*

Ebay scalers
GBS 8200 v4.0 (2010.10.29)
all resolutions worked after hitting the sw button after doing a switch, however if running any video it will only work on 640 x 480 and 1024 x 768 modes. On 800 x 600 and 1360 x 786 it either has no scanlines *normal* or makes the image unstable *wide*. This seems to be the case for all three inputs types.

GBS 8220 V3.0 (2010.12.20)
same as the gbs 8200, worked better with the middle vga port.

DC VGABOX (DC Super VGA BOX (DC2000/February 2008 KENT) *on bottom* XK-DC 2000)
Causes "VGA no signal", however running it though one of the ebay scalers causes it to work, very weird.

Good stuff Masa.
First, the stupid question. How do you adjust the outgoing resolution with the Xbox360 cable? Is there a resolution setting on the display settings of the console I haven't seen yet?

I'll do my best to match these on my equipment to determine the cause. Very appreciated.

[StarCreator]

First, the stupid question. How do you adjust the outgoing resolution with the Xbox360 cable? Is there a resolution setting on the display settings of the console I haven't seen yet?

The video settings change to using PC resolutions rather than HDTV resolutions when using a VGA cable. Always have.

I've also never seen a third party 360 VGA cable perform satisfactorily at high resolutions - they are just never properly shielded or something and you get a lot of visible interference. I had to switch to Microsoft's own cable to get a clean picture.

[fagin]

HDFURY or HDFURY gamer edition output the correct sync and work. HDFURY3 will output the correct sync if you change the dip sw setting on the HD3 to suit.

I will have to correct you, as the HD Fury gamer edition don't work with the SLG 3000. It was my first choice when i bought the SLG 3000, but unfortunately it don't work. My setup have the HD Fury 3 now.

Apologies and thanks (finally) for a confirmed standing on this from someone that has tried it. Since the Gamer Ed. is supposed to be based on the HDF1, it was envisaged that the Gamer Ed. would be fine.... as least we have confirmation now.

[BuckoA51]

Oh, the Gamer Edition of the Fury works does it? Good to know I could have sworn somewhere I read that it did not.

The problem with the HDFURY2 output working effectively with the SLG is the sync polarity, plain and simple.

Confirmed, put the SLG3000 behind an Extron RGB interface (VGA Source->HD Fury 2->Extron RGB->SLG3000->Display) and turn on the NEG SYNC switch on the Extron and it works. Since the Extron interfaces are a lot cheaper than upgrading to a Fury 3 this will do nicely for me.

[matrigs]

tried to solder this together two times today. no luck. had 2 sets of chips. soldered it directly to the ebay-scaler as shown on mmmonkey with no luck. a lot of flicker and weird stuff on the screen but no scanlines.

[fagin]

Bucko,
Re-read what was said about the HDF2 above. It's been confirmed it doesn't work.

[BuckoA51]

What doesn't work, the HD Fury gamer edition?

[fagin]

Sorry mate... I meant the HDFURY gamer edition.

[matrigs]

scanline galore. ps2-ebay scaler-homebrew scanline generator.

looks fantastic. for those few bucks i invested i don't even give a damn about damaging the ebay-scaler in the long run.