By way of an intro, a cool feature of using RGB on a Scart equipped consumer TV is auto input and aspect ratio selection and RGB mode selection. This realized through passing the appropriate voltage through Pin 8 (0–2 V → off, +5–8 V → on/16:9, +9.5–12 V → on/4:3) and Pin 16 (0–0.4 V → composite, 1–3 V → RGB).
Obviously for retro gaming one wants the 4:3 aspect ratio, but the problem that comes into play is that not all consoles output 9-12V through the AV out connector. An example of this is the NTSC SNES or a Mega Drive as well as machines retrofitted with RGB (e.g. PC Engine). The result is a 16:9 image upon power up and the need to manually change the aspect ratio each time the power switch is flicked e.g. when changing a cart – pretty annoying.
Below is a quick guide on how this can be rectified, through the use of a DC to DC convertor using the PCE as an example.
The convertor in question – a QLT POWER QDC1S-0512S:
Converts 5V into 12V and is small enough to fit into a scart plug hood.
All wired up:
The terminals are input GND, input +5V (yellow), output GND, output +12V (red). Grounds (black) have been connected together.
Standard PCE scart plug gives 5V on Pin 8 and Pin 16 getting c.a. 3V though a 180ohm resistor:
Connected up – red to pin 8 and yellow to the 5V line. +5V from the console goes to the DC-to-DC convertor and to Pin 16 via the resistor:
Final step which I did before closing everything up is to wrap the DC-to-DC convertor in electric tape. As a guidance, longer wires aid being able to maneuver / move the convertor around the scart plug so that it can be closed up without any hassles:
End result upon power on:
Top right corner – correct AV input is selected and RGB in enabled
Bottom middle – correct 4:3 aspect ratio is selected
Bottom right corner – stereo sound is enabled
Hope this comes in useful for someone – obviously more applicable to folks with Euro spec Scart TVs than PVM / BVM’s but pretty neat all the same. In terms of approximate costs, I got the convertor from a local electronics store for c.a. $5 so probably can get one for less online.
Thanks for reading!
Obviously for retro gaming one wants the 4:3 aspect ratio, but the problem that comes into play is that not all consoles output 9-12V through the AV out connector. An example of this is the NTSC SNES or a Mega Drive as well as machines retrofitted with RGB (e.g. PC Engine). The result is a 16:9 image upon power up and the need to manually change the aspect ratio each time the power switch is flicked e.g. when changing a cart – pretty annoying.
Below is a quick guide on how this can be rectified, through the use of a DC to DC convertor using the PCE as an example.
The convertor in question – a QLT POWER QDC1S-0512S:
Converts 5V into 12V and is small enough to fit into a scart plug hood.
All wired up:
The terminals are input GND, input +5V (yellow), output GND, output +12V (red). Grounds (black) have been connected together.
Standard PCE scart plug gives 5V on Pin 8 and Pin 16 getting c.a. 3V though a 180ohm resistor:
Connected up – red to pin 8 and yellow to the 5V line. +5V from the console goes to the DC-to-DC convertor and to Pin 16 via the resistor:
Final step which I did before closing everything up is to wrap the DC-to-DC convertor in electric tape. As a guidance, longer wires aid being able to maneuver / move the convertor around the scart plug so that it can be closed up without any hassles:
End result upon power on:
Top right corner – correct AV input is selected and RGB in enabled
Bottom middle – correct 4:3 aspect ratio is selected
Bottom right corner – stereo sound is enabled
Hope this comes in useful for someone – obviously more applicable to folks with Euro spec Scart TVs than PVM / BVM’s but pretty neat all the same. In terms of approximate costs, I got the convertor from a local electronics store for c.a. $5 so probably can get one for less online.
Thanks for reading!
