Intellivision Board details

[raspberrypioneer]

Sorry I missed your post yesterday, it was our wedding anniversary so we were out all day. That info kind of ties in with what we've seen I think, the single transistor comp mods are good but not always best for some circumstances.

No worries, good to get the priorities right! Yeah the TFW8B board might be fine but for few quid more should get the results you have, fingers crossed.

Sounds like a plan. I doubt the shunt circuit would take much to build, there isn't a lot to it, and I think now my Winmar mod is working pretty well for sure.

Aside from the electrolytic caps, the Winmar mod is all SMD, and there it a ton of space in the case so no issues there.

I decided to check the voltage going into the RF modulator expecting 12v as the shunt works with that. But in my (our?) case got a steady 4.82v! Maybe it's our Radofin boards maybe all PAL boards? For the composite mod (PAL), potentially no shunt needed. I'm tempted to just power the comp mod from this input which would be very convenient. I could see the PAL board is getting 12v.

Yeah, the TRRS ports are very good for this sort of thing, and look great on my 2600 and 7800, I just added cables on my Intellivision because I wanted it to be reversible, so no case mods, and the hole for the modulator is pretty big, I did a similar thing on my Coleco and Tandy Coco too.

I might be changing my mind here. Looking for the TRRS port, I couldn't find something that I thought was suitable. Then wondered about just outputting composite via a 5 pin DIN instead. I'd be able to save on a lead by reusing the CBM/Atari one I have. Found a suitable female DIN connector which should mean no change to the case, looks like it will slot into the gap where the RF port is.

Need to order the caps next. Retroleum have all but one of them - the 2200uF 25v so its eBay for that one. Might not change the regulators as they checked out fine. I have changed the horrible ribbon cable though, with just the little investigation I did, it began to fall apart!

[rubber_jonnie]

No worries, good to get the priorities right! Yeah the TFW8B board might be fine but for few quid more should get the results you have, fingers crossed.

Yeah the TFW8bit board is a very common comp mod, but I think I tried a home built version (I've built my own for a few machines now) in mine come to think of it, and it didn't work, hence why I ended up with the Winmar version.

I decided to check the voltage going into the RF modulator expecting 12v as the shunt works with that. But in my (our?) case got a steady 4.82v! Maybe it's our Radofin boards maybe all PAL boards? For the composite mod (PAL), potentially no shunt needed. I'm tempted to just power the comp mod from this input which would be very convenient. I could see the PAL board is getting 12v.

No reason you can't take the 5v from the modulator.

Yeah, I couldn't find 12v anywhere near the modulator (though there is a 12v rail on the mainboard) just the 5v, hence why I think mine, and probably yours too will work without the shunt, and I have a theory about that.

Because the boards we have also have the PAL demodulator board with the TBA520 installed, the graphics IC is feeding that board, and that board is making sure the graphics IC always has 5v on the output.

I strongly suspect that NTSC machines only require the shunt because they don't have that additional PAL board, meaning that as soon as the modulator is gone, so is the 5v on the graphics IC output. I wish there was more info on the PAL board, it'd be useful to know.

I might be changing my mind here. Looking for the TRRS port, I couldn't find something that I thought was suitable. Then wondered about just outputting composite via a 5 pin DIN instead. I'd be able to save on a lead by reusing the CBM/Atari one I have. Found a suitable female DIN connector which should mean no change to the case, looks like it will slot into the gap where the RF port is.

Need to order the caps next. Retroleum have all but one of them - the 2200uF 25v so its eBay for that one. Might not change the regulators as they checked out fine. I have changed the horrible ribbon cable though, with just the little investigation I did, it began to fall apart!

Luckily I keep quite a large stock of caps, but that big 2200uF one I had to order in specially too, eBay for me too.

The Intellivision does have a lot of space around the modulator port, so feeding cables through even with the modulator still in place is easy. Having a small dongle out the back really isn't any bother, in fact when I installed a Super Colour CPU Card in my Atari 400, I did exactly that, so I have a 5 pin DIN socket that I can plug a standard composite cable into, so sounds reasonable to me.

As for the little ribbon cable, yep it's awful and needs to be history

[raspberrypioneer]

Yeah the TFW8bit board is a very common comp mod, but I think I tried a home built version (I've built my own for a few machines now) in mine come to think of it, and it didn't work, hence why I ended up with the Winmar version.

I've ordered the Winmar version too. I think it is the 'standard' Intellivision composite mod, same the the other option I was looking at.

No reason you can't take the 5v from the modulator.

Yeah, I couldn't find 12v anywhere near the modulator (though there is a 12v rail on the mainboard) just the 5v, hence why I think mine, and probably yours too will work without the shunt, and I have a theory about that.

Because the boards we have also have the PAL demodulator board with the TBA520 installed, the graphics IC is feeding that board, and that board is making sure the graphics IC always has 5v on the output.

I strongly suspect that NTSC machines only require the shunt because they don't have that additional PAL board, meaning that as soon as the modulator is gone, so is the 5v on the graphics IC output. I wish there was more info on the PAL board, it'd be useful to know.

I think you're right - the PAL board (well at least our Radofin type) means 5v is output to the RF modulator. I would have expected the mod from the world of Jani site (also PAL) to have taken 5v from this point too but perhaps that was overlooked or other PAL boards still do 12v.
It's really handy you've got the same Radofin Intellivision as me and I'm mostly following the same path!

Luckily I keep quite a large stock of caps, but that big 2200uF one I had to order in specially too, eBay for me too.

The Intellivision does have a lot of space around the modulator port, so feeding cables through even with the modulator still in place is easy. Having a small dongle out the back really isn't any bother, in fact when I installed a Super Colour CPU Card in my Atari 400, I did exactly that, so I have a 5 pin DIN socket that I can plug a standard composite cable into, so sounds reasonable to me.

As for the little ribbon cable, yep it's awful and needs to be history

I asked about the 2200uF 25v after placing the order with Retroleum and they can supply it, same price as eBay, so that's the plan, will just add a few days!

Part of me thinks keep the RF video and add composite either with a trailing lead or a case mod (which I don't like as a general rule), then will I or anyone ever use RF video in future, so just replace? Not being too decisive here, I've a few more days before stuff arrives to ponder over it.

[rubber_jonnie]

I've ordered the Winmar version too. I think it is the 'standard' Intellivision composite mod, same the the other option I was looking at.

Cool, it definitely works

I think you're right - the PAL board (well at least our Radofin type) means 5v is output to the RF modulator. I would have expected the mod from the world of Jani site (also PAL) to have taken 5v from this point too but perhaps that was overlooked or other PAL boards still do 12v.
It's really handy you've got the same Radofin Intellivision as me and I'm mostly following the same path!

I think with the Intellivision being big in the US, the PAL specs get overlooked and it does in a way make life easier since with our boards the shunt seems unecessary.

I asked about the 2200uF 25v after placing the order with Retroleum and they can supply it, same price as eBay, so that's the plan, will just add a few days!

Nice and easy then

Part of me thinks keep the RF video and add composite either with a trailing lead or a case mod (which I don't like as a general rule), then will I or anyone ever use RF video in future, so just replace? Not being too decisive here, I've a few more days before stuff arrives to ponder over it.

Disconnecting the modulator definitely helped mine I think, and the trailing lead means no issues with cutting the case, which I'm not keen on. No reason you can't leave the modulator installed but inactive if you're going to do a flying lead.

[raspberrypioneer]

Cool, it definitely works

Some news to report! I replaced all the caps and completed the video mod (Winmar), which both arrived yesterday. Being steady and slow it took a while!

I'm using my C64/Atari composite lead but had to jimmy a connection to the video mod-board for now, as I've not received the 5 pin DIN female snap-in connector yet. I couldn't wait to see what the video output would look like!

Video quality is a bit sharper but that nasty video tearing on the top part of the screen still appears just as I had with RF output! In a way it's worse because I could fine-tune that out! Was feeling a bit despondent but remembered you trying a different TV/monitor and I did the same. And wow - what a difference that makes! The video quality is sharp, no tearing, shimmering and colours are clear.

I guess I've pretty much repeated the journey you've been on! You basically need to do the video mod and get a different TV!

Anyway, very happy with the results, I'll post some pictures of the end result once I get the 5 pin DIN connection properly set-up.

[rubber_jonnie]

Cool, it definitely works

Some news to report! I replaced all the caps and completed the video mod (Winmar), which both arrived yesterday. Being steady and slow it took a while!

I'm using my C64/Atari composite lead but had to jimmy a connection to the video mod-board for now, as I've not received the 5 pin DIN female snap-in connector yet. I couldn't wait to see what the video output would look like!

Video quality is a bit sharper but that nasty video tearing on the top part of the screen still appears just as I had with RF output! In a way it's worse because I could fine-tune that out! Was feeling a bit despondent but remembered you trying a different TV/monitor and I did the same. And wow - what a difference that makes! The video quality is sharp, no tearing, shimmering and colours are clear.

I guess I've pretty much repeated the journey you've been on! You basically need to do the video mod and get a different TV!

Anyway, very happy with the results, I'll post some pictures of the end result once I get the 5 pin DIN connection properly set-up.

Yeah, sounds like we've had exactly the same journey

I have 2 small 10" displays, I like them because they have HDMI, Composite + Audio, BNC and USB connections, they are great little workbench displays, but like you, I get the tearing with both and they are different revisions a year or so apart.

I also get weird issues with my OSI C1-MPF which as built has NTSC composite, which both are capable of, but the display goes weirdly bright after a period of time, and if I unplug the OSI video cable and plug it back in again, then it fixes itself. very odd.

I also have a larger Dell display that also has composite, and that doesn't like the Intellivision either, though it's an improvement on the 10" displays. My LCD TV though, works fine.

In comparison my Colecovision looks sweet on anything. Does make me wonder if it's something to do with the PAL board, so I have replacement PAL IC's now so I'll swap one in at some point, hopefully this weekend.

[stephen_usher]

Dell display composite input is usually 60Hz NTSC only from my experience.

[rubber_jonnie]

Dell display composite input is usually 60Hz NTSC only from my experience.

Mine seems take either PAL fine, but NTSC from my OSI C1-MFP it really doesn't like.

But I don't have anything else NTSC to try it with so it's difficult to know for sure. Will check the menu see what it can do.

[raspberrypioneer]

I have 2 small 10" displays, I like them because they have HDMI, Composite + Audio, BNC and USB connections, they are great little workbench displays, but like you, I get the tearing with both and they are different revisions a year or so apart.

I also get weird issues with my OSI C1-MPF which as built has NTSC composite, which both are capable of, but the display goes weirdly bright after a period of time, and if I unplug the OSI video cable and plug it back in again, then it fixes itself. very odd.

I also have a larger Dell display that also has composite, and that doesn't like the Intellivision either, though it's an improvement on the 10" displays. My LCD TV though, works fine.

I was very surprised how much of a difference the TV makes for composite display! I don't have any special video monitors. The Samsung LCD TV I've been using for a while for retro stuff has all the main video input connections available, it handles both composite and component/RGB video really well. It could be a bit sharper for the VIC20 I've got, but otherwise no complaints. Until the Intellivision that is! I'm using a Goodmans LCD TV we've had hanging around as a spare instead now. It's a pretty old model probably late 2000's. The quality difference is like night and day! I've tried quite a few games to be sure

In comparison my Colecovision looks sweet on anything. Does make me wonder if it's something to do with the PAL board, so I have replacement PAL IC's now so I'll swap one in at some point, hopefully this weekend.

I think the different frame-rate causes the tearing. I know almost nothing about this so did a bit of googling! The Intellivision can output 60fps, but apparently most games output 20fps, because they use the EXEC framework which sounds like a library of standard ROM functions (probably why most Mattel games have a similar feel). I noticed some games weren't affected by the tearing problem so perhaps they didn't use the EXEC framework. PAL is 25fps and I guess some TVs compensate better than others with this. I wonder was the Colecovision does?

It will be interesting to see how you get on with the PAL ICs. Perhaps RGB output would provide a more consistent experience. I've seen that RGB mods have been done in the past but it doesn't seem that they're available to buy now.

[rubber_jonnie]

I have 2 small 10" displays, I like them because they have HDMI, Composite + Audio, BNC and USB connections, they are great little workbench displays, but like you, I get the tearing with both and they are different revisions a year or so apart.

I also get weird issues with my OSI C1-MPF which as built has NTSC composite, which both are capable of, but the display goes weirdly bright after a period of time, and if I unplug the OSI video cable and plug it back in again, then it fixes itself. very odd.

I also have a larger Dell display that also has composite, and that doesn't like the Intellivision either, though it's an improvement on the 10" displays. My LCD TV though, works fine.

I was very surprised how much of a difference the TV makes for composite display! I don't have any special video monitors. The Samsung LCD TV I've been using for a while for retro stuff has all the main video input connections available, it handles both composite and component/RGB video really well. It could be a bit sharper for the VIC20 I've got, but otherwise no complaints. Until the Intellivision that is! I'm using a Goodmans LCD TV we've had hanging around as a spare instead now. It's a pretty old model probably late 2000's. The quality difference is like night and day! I've tried quite a few games to be sure

In comparison my Colecovision looks sweet on anything. Does make me wonder if it's something to do with the PAL board, so I have replacement PAL IC's now so I'll swap one in at some point, hopefully this weekend.

I think the different frame-rate causes the tearing. I know almost nothing about this so did a bit of googling! The Intellivision can output 60fps, but apparently most games output 20fps, because they use the EXEC framework which sounds like a library of standard ROM functions (probably why most Mattel games have a similar feel). I noticed some games weren't affected by the tearing problem so perhaps they didn't use the EXEC framework. PAL is 25fps and I guess some TVs compensate better than others with this. I wonder was the Colecovision does?

It will be interesting to see how you get on with the PAL ICs. Perhaps RGB output would provide a more consistent experience. I've seen that RGB mods have been done in the past but it doesn't seem that they're available to buy now.

My TV is just a cheap Techniica LCD I've had for years, but it's handy as my 'everything TV. I feed it SCART, Composite, HDMI, component, VGA and UHF, it handles them all just fine. I do have another one that is a bit older and not so well connected. I do also have a real CRT, a 14" colour TV, it's not ideal but it does the trick when I need it to. I think my TV is mid-2000's TBH.

Most of my retro gear feeds composite into my Retrotink 2x and then on to the TV using HDMI and in almost all cases it's just fine. I do use some via my OSSC but that tends to mostly be where my cables are SCART, and the Retrotink doesn't handle that.

I don't think I'll get round to the TBA520 this weekend as I have my light sixer on the bench in bits waiting for a CleanComp mod to arrive.

My little display does have PAL-60 available, but I normally leave it in auto. I guess the tearing at 60 FPS could be a thing, but I'm not sure that is what the Pirto II runs at and I get tearing on the menu, unless I use my TV.