How do I make a CPC-RGB DIN to RCA -RGB or Composite cable?

[DistantStar001]

Much as the title says: I have an Amstrad CPC464 with its matching monochrome monitor/PSU. However, I want color! Unfortunately, whenever I Google or search eBay for options all I get are SCART adaptors, and if you couldn't tell from my spelling of the word color, I'm in the U.S. Thus SCART compatible monitors aren't really a thing out here, and importing a color Amstrad or SCART enabled monitor is kinda cost prohibitive. So I need a means of connecting what I have.

I do have several PAL capable monitors. And at least two of them have RGB inputs. However, they use 3 RCA inputs designed to receive the sync signal on the Green input. This has not been a problem for my Spectrums, PAL Commodores, or BBC Micro, but all of those have composite.

The issue is that all of the pinouts that I've seen separate the sync and luminance signals on separate pins. Which, as far as I can tell, an RCA input will need both. But on which line???

If anyone has built this cable before, assuming it's possible at all, I would appreciate some instruction or maybe a schematic laying out all of the connections.

 

[DistantStar001]

OK. working from the pinout pictured below, I have been able to workout a 6 to 5 pin adaptor using jumper wires and a headboard that will allow me to use a 5-pin DIN to 4-line RCA cable to breakout the red, green, and blue signals. Luminance and synch are routed to the Green line since that's where the monitor is expecting them. This gives me Blue and Red as expected, but no Green. Also, the text is pink which makes sense since yellow should be a combination of green and red. I've tried just using luminance or sync and while I still get a signal, green is still absent.

Interestingly, eliminating the Green line to the monitor (keeping luminance and sync) causes the text to go Red. So I think the Green signal is there, but it appears to be getting washed out, or is weak for some reason.

Any ideas on how I can get a proper green signal?

 

[cj7hawk]

As you have noted;

Is it possible to use an Amstrad CPC464 with a modern monitor or TV

During a recent move I lost the monitor for my Amstrad CPC464. Is it possible to adapt the output of this to work on a modern monitor or on television set?

retrocomputing.stackexchange.com

So you need a RGB to composite, or RGB to VGA or just a 15KHz RGB monitor... Probably one of the Dell monitor should accept it OK...

If you get no green, then most likely I would guess there's a problem with the computer, cable or monitor. I've never heard of anything specific wrong with the Amstrad RGB connector.

 

[wmcbrine]

Why don't you tell us the actual monitor(s) you're trying to work with, and maybe we can figure it out from there?

 

[DistantStar001]

Why don't you tell us the actual monitor(s) you're trying to work with, and maybe we can figure it out from there?

Honestly, I'm trying to get as generic a signal as possible to work with a wide variety of monitors. Composite is ideal, but I figured that Component or S-Video would be easier (I'm likely wrong about that). That said, the two monitors I'm working with are a Sharp Aquos LC-13S1U-S as well as an Insignia NS-LCD15. Additionally, I have an Insignia NS-19310A13, but it's a lot more temperamental with the signals it will accept.

All three have composite, component (sorry I meant to say component not RGB in the first post), S-Video, and RF. The Insignias also has VGA and HDMI as well.

I also have a TLC smart tv, but that only has Composite, RF and HDIMI.

 

[cj7hawk]

Honestly, I'm trying to get as generic a signal as possible to work with a wide variety of monitors. Composite is ideal, but I figured that Component or S-Video would be easier (I'm likely wrong about that). That said, the two monitors I'm working with are a Sharp Aquos LC-13S1U-S as well as an Insignia NS-LCD15. Additionally, I have an Insignia NS-19310A13, but it's a lot more temperamental with the signals it will accept.

All three have composite, component (sorry I meant to say component not RGB in the first post), S-Video, and RF. The Insignias also has VGA and HDMI as well.

I also have a TLC smart tv, but that only has Composite, RF and HDIMI.

If you're sticking RGB into Blue-Red component video, well that would explain the lack of green. I would not even go there as an objective. Amstrad's output is RGB and Sync.

Best would be a RGB to HDMI adapter. There was one in the article I linked to. That should get your RGB to VGA and HDMI - But you can also get a 15KHz capable VGA LCD screen and just make a cable up from Amstrad RGB to VGA and that will work fine -

Added: You can also get something like the Extron DVS 204 or DVS 304 Video scaler which does this too - and is a professional unit for this purpose... Pretty cheap secondhand.

 

[clueless_engineer (Brett)]

I use a cheap GBS8200 converter board (AU$30 from Aliexpress) that accepts RGBS and output VGA, then make up a simple DIN-to-RGBS cable as required. I then either use the VGA directly or, to capture video for my YT channel, I then use a VGA-to-HDMI converter and HDMI-to-USB converter.

Of course, you can also buy an already upgraded "GBS Control" from eBay or Aliexpress, or upgrade a GBS8200 yourself.

This is the Amstrad RGBS cable I made. I make up a cable for any RGBS-capable computer, like post-Soviet Speccy clones.



I buy a bunch of these RGBS cables so I can make up new DIN-to-RGBS cables as required for different computers.

 

[bola_dor]

You need a 15khz 50HZ. You ca use a GBS8200 but will need to work the Csync signal or a GBS-C (expensive).. I bought an omd used 15" Sony TV from Europe.. problem solved.... buy the cables also...
A more general signal? Use an ad724jr based converter to composite or S-video... search Amiga sites as they've been struggling with this since the 90's....

 

[clueless_engineer (Brett)]

You need a 15khz 50HZ. You ca use a GBS8200 but will need to work the Csync signal or a GBS-C (expensive)..

I just make the DIN6 cable direct to the stock GBS8200 (ignoring LUM signal) - never had an issue. It's probably not 4K HDR pixel perfect for an 80" TV but is sufficient for my requirements (including capturing video for 4K YouTube videos).

This is my most recent example: CPC -> stock GBS8200 -> VGA-HDMI converter -> HDMI-USB converter then captured with Quicktime on my Mac.

The additional VGA -> HDMI -> USB is just so I could capture the video for YouTube, otherwise it would've been just CPC -> GBS8200 -> VGA.