gscartsw / gscartsw_lite / gcompsw switches support thread

[gearheadtocz]

One final question hopefully. The 5vp-p of ttl and 600mv p-p of 75ohm csync.....are these readings in DC or A.C.?

Can these be measured with a multimeter while under load or is a osciloscope nesecessary?

[superg]

One final question hopefully. The 5vp-p of ttl and 600mv p-p of 75ohm csync.....are these readings in DC or A.C.?

Can these be measured with a multimeter while under load or is a osciloscope nesecessary?

TTL is always DC. Why would you want to measure it?

[gearheadtocz]

Recently I've heard how too high sync voltage can possibly damage certain devices like the framemeister. (This was a podcast discussion between the hdretrovision guys and voultar)
So I want to see for myself exactly what is being input into my monitors and scalers.
I've heard conflicting info at times as well. I've had a retired sony bvm tech tell me that sync needs to be measured with a scope in AC. Rene from db electronics said a scope was necessary as well.

I have a fairly rare input card in my bvm that I want to be certain I'm not damaging. The spec on that is 0.3v - 4v p-2p for external sync.
While my other bvm supposedly can accept up to 8v.
Some pvms max out at 1v of sync input.

I feel good knowing the gscart won't pass a high sync voltage but I have many other switchers mainly from extron which all output 5v TTL sync.
I'd need another 4 gscart's to take them out of the equasion haha!

[Wolf_]

Recently I've heard how too high sync voltage can possibly damage certain devices like the framemeister. (This was a podcast discussion between the hdretrovision guys and voultar)
So I want to see for myself exactly what is being input into my monitors and scalers.
I've heard conflicting info at times as well. I've had a retired sony bvm tech tell me that sync needs to be measured with a scope in AC. Rene from db electronics said a scope was necessary as well.

I have a fairly rare input card in my bvm that I want to be certain I'm not damaging. The spec on that is 0.3v - 4v p-2p for external sync.
While my other bvm supposedly can accept up to 8v.
Some pvms max out at 1v of sync input.

I feel good knowing the gscart won't pass a high sync voltage but I have many other switchers mainly from extron which all output 5v TTL sync.
I'd need another 4 gscart's to take them out of the equasion haha!

My god. What 32 systems do you have?

[superg]

Recently I've heard how too high sync voltage can possibly damage certain devices like the framemeister. (This was a podcast discussion between the hdretrovision guys and voultar)
So I want to see for myself exactly what is being input into my monitors and scalers.
I've heard conflicting info at times as well. I've had a retired sony bvm tech tell me that sync needs to be measured with a scope in AC. Rene from db electronics said a scope was necessary as well.

I have a fairly rare input card in my bvm that I want to be certain I'm not damaging. The spec on that is 0.3v - 4v p-2p for external sync.
While my other bvm supposedly can accept up to 8v.
Some pvms max out at 1v of sync input.

I feel good knowing the gscart won't pass a high sync voltage but I have many other switchers mainly from extron which all output 5v TTL sync.
I'd need another 4 gscart's to take them out of the equasion haha!

The oscilloscope is an only reliable way to see it. But I'd advice not to use anything TTL related, only 75ohm loaded and everything will be fine.
I'm not familiar with Extron, is it TTL only?

[gearheadtocz]

I have lots of different versions of the usual consoles I guess. Different rooms with multiple monitors I think over 45 consoles and yes I need help

Extron products usually output ttl. The crosspoint series seem to be popular with retro gamers because they can be found for cheap and were originally very very expensive and very high quality if you have the room for them. All connections are typically bnc but there are dsub15 models as well.
A lot of their products can convert any sync including sog to whatever sync you prefer which is also a great feature. You could for example have one console input RGBs, another RGsB and another RGBHV and then have it output it all RGBs without changing any settings between consoles.
This is another reason I am looking forward to the gscart lite for the similar features in a much smaller form factor.

Extrons generally seem to output TTL level 5v unterminated according to the product specs.
I recently tested on my mitsubishi megaview via an extron Rxi 201, under load with a twin famicom (nesrgb) displaying an all white screen and the sync output was 4.5v unterminated and about 2.1v when terminated with the built in monitor switch...im guessing 75ohm?
I used a Y cable to split the sync output and a typical multimeter in the dc setting to get these readings.
Other consoles like the Snes 1 chip (original model) and snes mini (voultar's mod) Gave the same basic results.

Do you think if I placed a resistor inline with the sync output of the extron that would make it potentially less harmful? What would the resistor value be around based on the info above?

[gearheadtocz]

Oh I forgot to mention the extrons accept 75ohm csync and ttl csync but they always output TTL so it dosent matter if the console has properly attenuated sync signals it does what it pleases with them.

[hyrulebr]

On the subject of Ps2 SoG will your cable support lightguns being plugged into it?
Also would you ever consider adding digital optical audio in on the gscart lite since the ps2 offers superior audio out via digital?

You mean composite (yellow) RCA break out or something else?
I'm still undecided about that SoG adapter form factor, I may do a SCART_female-SCART_male style thing.
As of optical support, no, I don't think so. If you're into hi quality audio you should own a receiver and there you can map and forward one of the optical inputs easily.

Yup, just simple composite video breakout for lightguns would be good because I love to play lightgun games but also really like 480p over scart.

And yes I do have my own receiver with multiple digital optical audio inputs but the PS2 is the only console that has analogue video and digital audio, probably because it's made by Sony. Anyways I have my analogue consoles go into an xrgb mini and that go into a hdmi switch with all my hdmi consoles so I only have 1 hdmi line in and I have a hdmi in to hdmi + digital optical audio out box and that is how I get all my audio out directly to my receiver on one line... with the exception of PS2 and having to switch audio inputs for 1 console just makes the ocd part of my brain freak out.

Xbox classic also have analogue video and digital audio...

[Milspex]

Waiting for that preorder date!

[superg]

I have lots of different versions of the usual consoles I guess. Different rooms with multiple monitors I think over 45 consoles and yes I need help

Extron products usually output ttl. The crosspoint series seem to be popular with retro gamers because they can be found for cheap and were originally very very expensive and very high quality if you have the room for them. All connections are typically bnc but there are dsub15 models as well.
A lot of their products can convert any sync including sog to whatever sync you prefer which is also a great feature. You could for example have one console input RGBs, another RGsB and another RGBHV and then have it output it all RGBs without changing any settings between consoles.
This is another reason I am looking forward to the gscart lite for the similar features in a much smaller form factor.

Extrons generally seem to output TTL level 5v unterminated according to the product specs.
I recently tested on my mitsubishi megaview via an extron Rxi 201, under load with a twin famicom (nesrgb) displaying an all white screen and the sync output was 4.5v unterminated and about 2.1v when terminated with the built in monitor switch...im guessing 75ohm?
I used a Y cable to split the sync output and a typical multimeter in the dc setting to get these readings.
Other consoles like the Snes 1 chip (original model) and snes mini (voultar's mod) Gave the same basic results.

Do you think if I placed a resistor inline with the sync output of the extron that would make it potentially less harmful? What would the resistor value be around based on the info above?

Basically you can use the calculation from here: http://www.gtsparkplugs.com/Dropping_Resistor_Calc.html
to get it from 5V TTL to 75ohm compatible you'll have to use 301ohm resistor.
(1V / 75ohm = 0.013A) 5V to 1V with current 13mA.

[superg]

Guys, I will still need 1-2 days to open the lite pre orders, please be patient.
Everything will be announced here and retrorgb will announce it as well.

[gearheadtocz]

Thanks again!
The final safe voltage should always be measured while terminated and everything connected under load correct?

[superg]

Thanks again!
The final safe voltage should always be measured while terminated and everything connected under load correct?

Yeah but umm, you'll need an oscilloscope for that.

[gearheadtocz]

Oh ok, damn.
Is there any way a dc reading can let me know if I'm in the general area of safe voltage?
Like if I added that 301ohm resistor to any device outputting ttl and now under load the voltage said it was close to 1v dc can I consider it safer than before?
Or is the ac voltage I cant read without a scope the more harmful part of ttl?

[hyrulebr]

I will open gscartsw_lite pre-orders early next week, preferably Monday. It will be open for 2 weeks and it will take up to 6 weeks until I will have them here. So I'd say 2 months from now.

Guys, I will still need 1-2 days to open the lite pre orders, please be patient. Everything will be announced here and retrorgb will announce it as well.

Will there a limited quantity or everyone that pre-order in that time frame will be served?

[superg]

I will open gscartsw_lite pre-orders early next week, preferably Monday. It will be open for 2 weeks and it will take up to 6 weeks until I will have them here. So I'd say 2 months from now.

Guys, I will still need 1-2 days to open the lite pre orders, please be patient. Everything will be announced here and retrorgb will announce it as well.

Will there a limited quantity or everyone that pre-order in that time frame will be served?

I usually keep it open for 2 weeks, whatever is ordered is getting produced.

[viletim]

Basically you can use the calculation from here: http://www.gtsparkplugs.com/Dropping_Resistor_Calc.html
to get it from 5V TTL to 75ohm compatible you'll have to use 301ohm resistor.
(1V / 75ohm = 0.013A) 5V to 1V with current 13mA.

It's more complex than that. Every sync output has different electrical characteristics. For example, the NTSC Super Nintendo's sync output is a transistor in an emitter follower config. It can source current, but not sink it. The Mega Drive has an open collector sync output with a 2.2k pull up resistor. It can't source current, only sink it.

gearheadtocz,

I don't think any of the common game console TTL sync outputs can source enough current to actually damage equipment.

[superg]

It's more complex than that. Every sync output has different electrical characteristics. For example, the NTSC Super Nintendo's sync output is a transistor in an emitter follower config. It can source current, but not sink it. The Mega Drive has an open collector sync output with a 2.2k pull up resistor. It can't source current, only sink it.

Makes sense, thanks for the clarification!

[superg]

As far as I can tell, at least in most cases, CSync cables actually use a console's CSync pin, but sellers include a resistor (or whatever it is you need) to get it from TTL to 75 Ohms. I don't think a sync stripper is used unless you explicitly need one, since most RGB-capable NTSC consoles have a CSync pin.

It's more complex than that. Every sync output has different electrical characteristics. For example, the NTSC Super Nintendo's sync output is a transistor in an emitter follower config. It can source current, but not sink it. The Mega Drive has an open collector sync output with a 2.2k pull up resistor. It can't source current, only sink it.

Actually I'm curious how that aligns with what they currently sell, does any manufacturer goes into details while making the csync cables?
Have anybody looked into that?

[RGB0b]

I'm curious how that aligns with what they currently sell, does any manufacturer goes into details while making the csync cables?
Have anybody looked into that?

Some sellers are more consistent then others. Most have changed over the years. As far as I know, the two main cable sellers should be adding the proper components for each console to bring the csync levels down to 75Ohm. If anyone has an older cable, it's worth opening and checking.

I'll have a list up soon on what to expect for each console. While you do need an oscilloscope to test the voltage, you'd just need to open the SCART head and visually check which cap is used. You can also use a basic multimeter to test if there's a resistor on the csync line. Adding or changing these components is extremely easy too. Maybe I'll launch the page "incomplete", just so people can have a reference?

[superg]

Maybe I'll launch the page "incomplete", just so people can have a reference?

That would be nice!

[naz]

Hello,

I created an account just to ask if the gcomsw will include a second output in a future revision (like the gscartw lite does). My objective is to have one output to the ossc and a second output direct to my consumer CRT.

Best regards

[RGB0b]

Maybe I'll launch the page "incomplete", just so people can have a reference?

That would be nice!

Here you go: http://www.retrorgb.com/csync.html

Please keep in mind that this is a work in progress. Within the next few months, I'll be double checking everything with an oscilloscope. For now, at least the consoles on top are confirmed by multiple people. Remember, capacitor values can be read and resistor values can be checked with a basic multimeter.

[gearheadtocz]

Basically you can use the calculation from here: http://www.gtsparkplugs.com/Dropping_Resistor_Calc.html
to get it from 5V TTL to 75ohm compatible you'll have to use 301ohm resistor.
(1V / 75ohm = 0.013A) 5V to 1V with current 13mA.

It's more complex than that. Every sync output has different electrical characteristics. For example, the NTSC Super Nintendo's sync output is a transistor in an emitter follower config. It can source current, but not sink it. The Mega Drive has an open collector sync output with a 2.2k pull up resistor. It can't source current, only sink it.

gearheadtocz,

I don't think any of the common game console TTL sync outputs can source enough current to actually damage equipment.

That's a relief to know!

So to be clear the TTL sync from consoles in general should still be attenuated to be a proper 75ohm signal but as is shouldn't be harmful?
Would the stock ttl signals be safe for the framemeister or did you mean bvms and other professional monitors?

[gearheadtocz]

Maybe I'll launch the page "incomplete", just so people can have a reference?

That would be nice!

Here you go: http://www.retrorgb.com/csync.html

Please keep in mind that this is a work in progress. Within the next few months, I'll be double checking everything with an oscilloscope. For now, at least the consoles on top are confirmed by multiple people. Remember, capacitor values can be read and resistor values can be checked with a basic multimeter.

Thank you so much bob and everyone helping with this!

[psxswiss]

Hi, quick question,I already have one gscartsw which gives me full satisfaction. I'm now looking to expand my setup and chain a second switch to the first one.
Can I Chain the gscartsw with a gsscartsw_lite?
Thanks much,

[superg]

The lite pre-orders are opened, http://gretrostuff.com, as usual please read all the terms before placing an order.

[Milspex]

Ordered!

[Dlang1987]

Ordered and very excited! Keep up the great work and thank you SuperG! (and Rob for retrorgb, Viletim Worthington, Voultar, and everyone else who contributes to the retro gaming community to keep this hobby/lifestyle alive!)

[VGCollectaholic]

Glorious! Order in. Thanks SuperG.

Also thanks to Bob for the great TTL/75ohm info.