Difference between revisions of "TV SCART cable"

Latest revision as of 07:37, 18 July 2023

A TV SCART cable allows to connect the CPC/CPCplus to the TV set. This is especially helpful if you couldn't get your hands on a colour monitor or want to use the CPC/CPCplus as a video console in the living room.

Schematics

Amstrad/Schneider CPC (classic)

Colour Picture (RGB)

This schematic requires a TV with RGB input on Scart Connector (back in the 8bit era, many TVs have had only Composite input implemented on Scart connectors - nowadays RGB is also supported by DVD players and 3D gaming consoles, which is possibly increasing the chance to find RGB support on modern TVs).

The 9V and 1.5V batteries are optional. Instead of the batteries, you may also extract the voltages from elsewhere (like the CPC supply).

They may be helpful to switch the TV to AV and RGB mode automatically, without needing to activate it via buttons on the remote control. Note that AV input can be usually selected using the remote control, while manual RGB input selection is only available on more recent TVs.

Battery duration: since Pin 16 (RGB input selection) has an input impedance of 75 Ohm, it will drain a common fully charged 1.2V ~2500mAh AA battery in about one week, if left connected permanently to the TV set.

Schematic for a CPC classic connection to a TV-set (Colour Picture) Note: The left and right sound channels are swapped in this diagram

John King's Comments about Scart Connections

The following information relating to the Scart Plug (Euroconnector/Peritel) could be found useful when concocting leads to connect your PCW, CPC or Spectrum +3 to a Television or Video recorder. The data has been checked against a number of technical references and should be correct.

Scart Plug viewed from the Pins.

John King's Comments about CPC to Television Scart Lead

I will start by saying that the tasks to be undertaken on this page are not for those of you without electrical and soldering skills, but for the competent, the following circuit will give a quality picture and stereo sound through a television set from an Amstrad CPC6128, a CPC664 or a CPC464. It has been tested on a number of different makes of TV (with complete success), within, the age range of 1 to 4 years. I have been unable to find anyone admitting to owning a TV without AV switching so no provision has been made in the offered lead for these old crocks.

• PARTS AND TOOLS REQUIRED.
  
• Scart Plug.
• 6 pin male DIN Plug.
• 3.5mm Stereo Jack Plug.
• 6 feet of six core cable.
• 7 feet of twin screened cable.
• 15 watt Soldering Iron.
• Solder.
• Electrical tape (or cable ties).
• MultiMeter.
• Side cutters, Long nosed pliers and a small screw driver (all of which can be found in any DIY tool box).

Just in case it is not obvious, use the six core cable to connect the DIN plug to the Scart plug and the Twin screened cable to connect the Jack Plug to the Scart Plug. The extra foot of twin screened cable runs from the Din plug (when the two cables are taped together) and plugs into the socket on the side of the CPC machine. Now that the Scart lead has been made up following the above diagram, tape the two leads together (or use the cable ties). Now you will need to turn to adding a suitable power supply to your CPC: Power_Supply_for_CPC_and_CPC_plus

It is well worth the effort of making up a Scart lead and power supply for your CPC machine, as the quality of picture and sound far exceeds that obtained through either a RF connection, via a modulator, or a green/colour monitor. Games are given a new meaning when played using a 28 or 32 inch wide screen TV.

NB Due to the nature of Television design there is a possibility that the lead will not work on every make and model of TV sold thoughout the world.

Foot note. Did you know what DIN indicates in the names of assortment of plugs and sockets use by most of our beloved games machines -- no it is not Drug Identification Number but in fact an acronym for Deutsche IndustriNorm --- so now you know.

© J.R.P.King. Updated 30th September 2003

Black & White Monochrome Picture

This schematic passes Luminance to the TVs Composite Input. It's giving only a monochrome picture, the advantage is that it works on nearly all TVs including such without RGB input.

Doing this would be useful only for using the TV as replacement for the GT64/GT65 monitor.

Bug: The 1.5V battery shown in the mono schematic is nonsense; for composite, Pin16 should be wired to GND, not to 1.5V.

Schematic for a CPCclassic connection to a TV-set (Black & White Picture) Note: The left and right sound channels are swapped in this diagram

Alternative RGB Wiring

Schematic to connect to RGB without requiring a 1.5V supply (Colour Picture) The 9V supply (as shown above) may still be required if the TV-Set has no AV Source Selector. If you experience picture flickering or the TV OSD appears intermittently while the CPC is connected, add a 100µf capacitor (optional) as shown above, this should resolve these problems. This setup won't work with all TVs. Some small 15" LCD TVs (for camping) have been reported to show ghost images with this setup, where a greyscale image is displayed besides the RGB image.

The alternative wiring has been reported to often not work with modern LCD TVs or Scart2HDMI converters. In those cases often a (bad) gray scale image will be displayed or there will be no picture at all. It is recommended to no longer use this wiring and instead provide a real 3V voltage on pin 16, e.g. by connecting it to the 5V power supply with the help of a simple voltage divider resistor:

Schematic to connect to RGB on a TV set without RGB switch. You can get the +5 VDC from the CPC power supply.

Amstrad CPCplus (In theory also GX4000, but it has its own SCART outlet)

Colour Picture (RGB)

Schematic for a CPCplus connection to a TV-set (Colour Picture)

John King's Comments about CPC Plus to Television Scart Lead

Perhaps I should start by saying that the tasks to be undertaken on this page are not for those of you without electrical and soldering skills, but for the competent, the following circuit will give a quality picture and stereo sound through a television set from an Amstrad CPC6128 Plus, a CPC464 Plus and GX4000. The lead has been tested on a number of different makes of TV (with complete success), within, the age range of 1 to 4 years. I have been unable to find anyone admitting to owning a TV without AV switching so no provision has been made in the offered lead for these old obsolete televisions.

• PARTS AND TOOLS REQUIRED.
• Scart Plug (also known as an Euroconnector or Peritel Plug).
• 8 pin male DIN Plug.
• 6 feet of six core cable.
• 6 feet of twin screened cable.
• 15 watt Soldering Iron.
• Solder.
• Electrical tape (or cable ties).
• MultiMeter.
• Side cutters, Long nosed pliers and a small screw driver (all of which can be found in any DIY tool box).

Just in case it is not obvious, use the six core cable to connect the DIN plug video/RGB connections to the Scart plug and the twin screened cable is for the sound connections to the Scart Plug. Now that the Scart lead has been made up following the above diagram, tape the two leads together (or use cable ties). Now you will need to turn to making a suitable power supply for your CPC Plus/GX4000 machine.

The GX4000 offers a Scart socket for connection to a TV (The Pin connections are listed wrongly in it's manual!). You will need to use the power supply (if not already defective) as issued with the machine, when using a Scart lead.

POWER SUPPLY.
You will need to find a Power Supply Unit giving a 5 volt regulated DC output. See this Wiki article for more information: Power_Supply_for_CPC_and_CPC_plus

It is well worth the effort of making up a Scart lead and power supply unit for your CPC Plus/GX4000 machines, as the quality of picture and sound far exceeds that obtained from a Black/White or colour monitor. Games are given a new meaning when played using a 32 inch wide screen Television.

NB Due to the nature of Television design there is a possibility that the lead will not work on every make and model of TV sold thoughout the world.

© J.R.P.King. Updated 27th July 2002.

Black & White Monochrome Picture

Schematic for a CPCplus connection to a TV-set (Black & White Picture)

Additional Resistors

Info from OCT: "I recall that when Amstrad Action came up with the proposal for a SCART cable back in issue AA41, numerous readers wrote in suggesting that resistors (most commonly: slightly below 330 ohms) should be connected "in series to the colour signals [...] for improving picture quality" (AA45, June 1989, FORUM, p. 23), so they seem to have appeared overblown in comparison to the CTM644s' back in the day."

The goal of that improvement is unknown - it might alter the medium-to-bright ratio, or, it might be simply intended to reduce the overall brightness (such like when the CPC picture appears brighter then normal TV programs). The voltage/brightness output by the CPC is actually higher than normal SCART voltages, however, the voltage drops when the TV applies load to the RGB pins; that load may vary from TV to TV, and so, the resistors may be needed only on some TVs, but not on others.

Videos

A SCART cable howto: https://www.youtube.com/watch?v=yNT36Tf6PxU

See also

• Connector:Monitor - Video output on the CPC
• Power_Supply_for_CPC_and_CPC_plus