Connect CPC to a VGA display

 

I always wanted to connect my CPC to a VGA display, but haven’t found a good solution to do this. During the last weeks I searched through eBay (search for “CGA VGA converter”) and found a seller in Hong Kong (eBay name “chowhe_taiwan”), who sells a CGA to VGA converter for a very cheap price (I paid at that time around 27 EUR including shipment).

It also was advertised for arcade machines, so I thought that this device should work with a CPC, too.

cga_vga_converter

To sum it up, this are the features of the device:

  • Supports CGA / EGA and YUV signal input
  • Support the following VGA output resolutions: 640×480, 800×600, 1024×768, 1360×768
  • CGA / EGA signal auto scan (15k, 24k, 31k)
  • YUV signal auto scan (480i, 576i, 720i, 1080i, 480p, 576p, 720p, 1080p)
  • Chinese and english on screen display (default is chinese, but you will find the menu to change the language easily)
  • Position & zoom control

After two weeks the kit arrived and I had the time to have a look at it and it works really fine. It only has some problems with demos which intensively use hardware effects. Btw, the demo “Batman Forever” works fine with this converter (except the multi-colour picture :-( ). I also tested some other demos which heavily used hardware effects and it seems that the converter works very good with them. Most of them work without any flaws.

To connect the device you have several options: you will find a connector on the left bottom side to directly connect the RGBS signal from the CPC to the converter, but I used the cable which was delivered with the device which is connected to the connector over the CGA 15pin SUB-D connector. The connection is really simple, but it depends on your CPC model of course.

This is the pinout of the connector cable:

Cable colorFunction
RedRed analogue signal
GreenGreen analogue signal
BlueBlue analogue signal
GreySync / RGB switching control
YellowVSync (don’t connect this)
BlackGND / Common

Connection to the Amstrad CPC (464, 664, 6128):

To connect the converter to the Amstrad CPC, you just have to connect each signal cable directly to the corresponding pin of the monitor connector of the CPC. Have a look at the pinout of the connector. I also added an image from my soldered connector, which might help you building your own connector.

Pin No.Signal NameDescription
1RRed analogue signal
2GGreen analogue signal
3BBlue analogue signal
4SyncRGB switching control
5GNDCommon
6LumLuminance

 

Cpc_monitor_pinoutcga_vga_converter_connector

 

Connection to the Amstrad Plus (464+, 6128+, GX4000):

The connection to the Plus is nearly the same, but you have a new pinout, because the Plus monitor connector contains two additional pins for audio output.

Pin No.Signal NameDescription
1SyncRGB switching control
2GGreen analogue signal
3LumLuminance
4RRed analogue signal
5BBlue analogue signal
6LLeft audio signal
7RRight audio signal
8GNDCommon

Plus_monitor_pinout

If you connected the wires correctly and switch on your CPC, you should see something similar to this image (I used a CRT in this test):

main_screen

And here are some screenshots which I took with my digicam of several demos:

demoizart

voyage_93

ultimate_megademo

After all I really like this device and it seems to work in most cases and I would definitively buy it again :-) !

  3 Responses to “Connect CPC to a VGA display”

  1. Does it work with demos using hardware screen distorsion (eg. Plasma Pas Cher, or Orion Prime introduction ?)

    The coloured picture in Batman Forever is because there is a slight timing error. I suspect you will get that on most early demos using screen splitting techniques, and on some modern ones too. From Scratch has such a bug in one case, too.

  2. Hi PulkoMandy,
    thanks for your comment. I haven’t tested the intro sequence of OP yet, but I will do it this weekend and will write about by results here.

  3. Ok, I tested the intro of OP and you are right: The screen distorsion is not working with this video converter, too. I am still happy with the output of the converter, because this happens only in very rare cases :) .

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