Increase screen resolution via composite output?

Here is a reference to the effect. It is given in terms of light output non-linearity (gamma) but I think it could be explained in terms of electrical non-linearity giving rise to the optical effect.

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Here is an interesting reference from the work done by the BBC in 1954 with NTSC colour test transmissions in London.

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(page 6)

APPENDIX 1

INCREASE IN APPARENT BRIGHTNESS ;"¦:? CHROMINANCE SUBCARRIER DOT STRUCTURE

DUE TO NON-LINEARITY OF PICTURE TUBE TRANSFER CHARACTERISTIC

Recent tests have revealed that the brightness of those portions of the screen of a picture tube in which chrominance subcarrier is present is greater than that of a comparison patch having the same luminance but no chrominance contribution. (continues in some detail).

--
Graham. 

%Profound_observation%
Reply to
Graham.
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It is correct that the nonlinear voltage-to-brightness transfer function will produce some brightening where chrominance amplitude is high. However, the magnitude of the effect is small enough in typical situations that observers do not find it objectionable--in fact, many prefer the increase in average brightness.

What many dislike when viewing a color video signal on a monochrome monitor is the strong dot pattern in saturated areas--more a problem when viewing close, as with a computer monitor.

Some later model B&W sets incorporated "color traps" to reduce the chroma amplitude, but most manufacturers considered this a luxury. ;-)

--
-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon
Reply to
Michael J. Mahon

It is a European, originally French, standard. It has appeared on almost all European TV sets in the past 30 years, but now it is disappearing because of the physically large size and the decision to not support HD on it.

Reply to
Rob

Please note that today you can buy a small Full-HD LCD (LED backlight) TV with all kinds of input you may ever want for half the price that I paid to get a CRT portable color TV with only SCART in the eighties.

And is in absolute price, not counting inflation.

You can also buy a Raspberry PI for 1/25th of what I paid for a simple

8-bit home computer with a couple of KB memory in 1980.

I think the kids should not complain.

Reply to
Rob

It actually is a very clever design. One connector to connect everything in one go (instead of fiddling with up to 5 cinch connectors to get only a single-direction connection). Cable is always a crossed connection so no matter what you connect to what, it always works with only one type of connecting cable. Autoswitching allows the TV to automatically determine the type of signal transferred and to select the proper input when an external device is switched on. Capable of bi-directional signal transfer.

Connector now is bulky but was compatible with build methods of those days (single layer PCB, hand-soldered cables). May look ugly but usually better contact than many other connector designs of the time, even in lowcost construction.

Reply to
Rob

Who's complaining?

The point of the RPi is that you *shouldn't* need to buy extra equipment to make it work.

Reply to
chris

Ah.. then I missed that point! I don't think I ever had a computer that I had to buy more extra equipment for to make it work than the Raspberry Pi.

Reply to
Rob

you can buy all inclusive pi kits,

OTOH can assemble an PC from parts

case, CPU, motherboard, RAM, disk drive. (options: video card, sound card, PSU(opften included with the case), optical drive)

--
For a good time: install ntp
Reply to
Jasen Betts

It sounds magic until you realise how many impossible combinations there are, and how many devices only implement part of the standard and just assume they're the only device ;)

SCART was reasonably good at what it did but it was still a long way off idiot proof :)

Reply to
Guesser

A Raspberry Pi is more like a PC motherboard. You need all kinds of parts and an enclosure in addition to the basic device.

Reply to
Rob

I beg to differ.

Perhaps you bought your Pi in a package, with software and peripherals included, and that's absolutely fine if you did.

But the whole point of the Raspberry Pi Foundation, was to offer the board only, at a low price.

That is what some of us find so attractive.

Take my Pi as an example, I bought it for a particular project. It runs headless, so a keyboard, mouse and screen are unnecessary, even for initial set-up.

The PSU I selected is a 3.8A one, chosen so it can also supply power to the other elements of my project.

SD cards are ubiquitous, as are the other items, so I got some to meet my needs.

Operating system and application software was available, as usual, as a downloadable image.

--
Graham. 

%Profound_observation%
Reply to
Graham.

Well the decision "not to support HD" is sensible. If you wanted to have high def analogue video inputs you would use VGA anyway, that way all the chips for interfacing it to your display already exist off the shelf.

Using analogue video signals to interface a digital video source with a digital monitor is crazy though and just adds hardware costs to products (at both ends of the cable) just so you can have a worse display.

Reply to
Guesser

But you can easily open the connector and clip that wire. Try to do that with a modern standard.

That must be a low priority for designers, as the HDMI connector, which has way less retaining force, doesn't have a clip either.

Reply to
Rob

Nope. Bought the bare board.

Maybe I wasn't clear. What I meant was that most people should have all they need to get an RPi running after buying the bare board - in addition to knowing what to do.

SD card (from camera) - check Power supply (from mobile phone) - check keyboard/mouse (from PC) - check monitor (TV) - check

A typical house has all the above. They may not all be spare, but can at least be borrowed when not otherwise being used.

Reply to
chris

That's just sad.

Reply to
Rob Morley

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