Getting an Interton VC 4000 functional in the US

[carlsson]

So I had some more spare time, and built myself a simple amplifier with three resistors and a transistor (same design as used on Atari 2600, 7800 etc). I had to measure a spot to pull 5V from. Neither of the two leftover inputs to the old RF modulator seems to be quite 5V but I found a place nearby which seems to work.

 

I found the RF modulator had partly come loose, and the wires needed somewhere to go anyway so I entirely removed the old RF modulator as it is no longer required and mostly in the way. Then I isolated all the wires individually, compacted the design and taped it to the motherboard. Now I'm getting a very nice picture even on LCD displays, both the 14" on the picture and that I've got a set of 7" wide displays to be used in a car DVD system but for which I previously made cables to connect any composite video input.

[carlsson]

Post scriptum: I found that the amplified picture was a bit too bright. Colours like green, yellow, cyan and white were almost indistinguishable on the LCD screen. I realized I probably can bring back the R10 pot from its 100% max position. At about 80% of max, I'm getting a stable picture that is full of colour, and since this is the screen that had most difficulty to display an image at all, I expect it to look good on other screens too, perhaps a little on the dark side but then again I don't feel like replacing the pot with a pair of wires and an externally adjustable pot like the currently inoperable one for volume.

[Derek Andrews]

Carlsson, thanks for sharing all this info. What exactly is that LCD you are running there? Is it a computer monitor or tv? What is its input format?

[carlsson]

It is a Samsung 14" LCD TV, can't recall its model number. It has inputs for composite video, S-Video (IIRC), SCART with RGB, VGA and RF antenna.

[Derek Andrews]

Presumably thought his tv is designed for a 50 Hz frame rate, or am I wrong? What concerns me about getting an Interton working in North America is that the tv or monitor won't sync at 60 Hz.

[carlsson]

This particular Samsung accepts either PAL or NTSC composite video, but in principle it is 50 Hz.

 

I didn't consider that your TVs and monitor displays are set to 60 Hz. I suppose that problem occurs with any PAL gear unless you go through some converter. Vice versa I tend to observe that if I feed a 60 Hz NTSC signal into a PAL TV or monitor not built for it, I get a solid image but without colours as they're on a different subcarrier on NTSC.

[pasmoi]

Hello,

 

To Alex_79 :

I just received an Interton VC 4000 in the hope of achieving the scart. I have the same model with daughter board. I have make the easy mod (close missing RF modulator for model with cards on top), but nothing at screen.

So, I just need to cut the 6 wires (red cross), soldering 2 of them (green lines) and remove the resistance. And soldering a scart cable with four 220 Ohm and one 270 Ohm resistances.

Is it that ?

 

Thanks.

Edited November 10, 2018 by pasmoi

[alex_79]

I have make the easy mod (close missing RF modulator for model with cards on top), but nothing at screen.

That mod only works for PAL consoles. If you have the same models as mine, then it's a SECAM one.

 

So, I just need to cut the 6 wires (red cross), soldering 2 of them (green lines) and remove the resistance. And soldering a scart cable with four 220 Ohm and one 270 Ohm resistances.

 

Yes, that's what I did and it worked fine for me.

[pasmoi]

Hi,

 

Works fine. Nice screen.

The sensitivity of the controllers is horrible, I did not remember that.

Thanks.

[ChildOfCv]

A little late to break in here with this, but a while back when I was buying movies from Germany I obviously needed a PAL format converter. The first method I came up with was to buy a TV tuner card for my computer. Almost all of them at the time supported all types even when they labeled for "NTSC" or whatever. Just go into the configuration and find the input format selection to flip it to one of the other modes.

 

I also found a VCR that can convert between systems.

 

Later I found a universal CRT television. It automatically detects and adapts to whatever encoding is used, when a composite signal is fed in. For TV reception you had to specify the expected system so that it could get its frequency ranges correct, and then you could auto-tune channels in. The model I got came with a European-style coax input plug, but also included a plug end that you can splice your own coax into. If you can find one of those on eBay or wherever, then you're all set.

[Derek Andrews]

While its not exactly the same console, I did just get my Voltmace Database running with an AV mod into a scaler and thence to HDMI to tv. https://sig2650.wordpress.com/2021/05/26/a-v-mod-for-the-voltmace-database/

[the_crayon_king]

I could make an RGB/YPbPr mod for this in like an afternoon.

It is very similar to the Arcadia > 2637. These should have the 2636?

 

I'll go ahead and write the code. The output should not be any better or worse than the existing RGB mod., except it can put out YPbPr and do multiple pallets.

 

If someone wants to work with me on testing an RGB/YPbPr let me know and I can make a kit for it. I don't personally own this console.

[Derek Andrews]

On 5/26/2021 at 10:18 PM, the_crayon_king said:

If someone wants to work with me on testing an RGB/YPbPr let me know and I can make a kit for it. I don't personally own this console.

I would be interested in trying it on YPbPr. Are you in North America or elsewhere? 

[the_crayon_king]

Just now, Derek Andrews said:

I would be interested in trying it on YPbPr. Are you in North America or elsewhere? 

All I did was use the same pallets as the Arcadia (full saturation) but it does have a secondary lighter pallet. I am in North America.

Really what I need is someone that knows where all the things are because I don't have this console in order to point things out.

I wrote the code but I really need to make sure that it mirrors the existing RGB schematic. I am just doing what they are doing but with code.

 

You would need to know where the O/S, C1, C2, C3 pins then blank sync and clock.

The attached picture shows the relevant points. There are 2.2k pullups on the schematic (for C1-C3 and O/S) but if those are not there then you will have to add them.

 

I forgot to mention, but this is unscaled YPbPr. You need something in order to interface with it., else if you sent it direct to the TV it would probably not look good if it even worked at all. If you are going to a old CRT then you are good to go.

 

Can you tell if there is enough room for the 5 RCAs you need for YPbPr + audio?

[D-Bloke]

Sorry to bump up an old topic but...........
I recently did the compo mod on mine (its the one with the boards slotted on top and ill im getting is a very dark image thats rolling a bit, tried adjusting the POT and it just went blank.
Tried another cable/TV and another TV and I still get the same.
Nocited it has a resistor attached to the front part where the metal shielding was, tried it with and with out it connecting and still got nothing.
Any ideas?
I have pressed the two backwards arrow button and other games
Previously the only TV I managed to tune it into was a Black and white one

[the_crayon_king]

On 2/17/2022 at 2:41 PM, D-Bloke said:

Sorry to bump up an old topic but...........
I recently did the compo mod on mine (its the one with the boards slotted on top and ill im getting is a very dark image thats rolling a bit, tried adjusting the POT and it just went blank.
Tried another cable/TV and another TV and I still get the same.
Nocited it has a resistor attached to the front part where the metal shielding was, tried it with and with out it connecting and still got nothing.
Any ideas?
I have pressed the two backwards arrow button and other games
Previously the only TV I managed to tune it into was a Black and white one

Rolling means you aren't getting good sync. 

Paired with the dark/black screen it would mean your whole signal is too low., making sync too low to be detected.

 

If I could get a hold of one of these I could make that thing I was talking about earlier in like an afternoon.

Edited April 6, 2022 by the_crayon_king