Here is a list of some TV shows that are in the public domain. Looks like 31 episodes of Bonanza are now out of copyright.
http://wiki.answers.com/Q/What…_are_in_the_public_domain
20th Century-Fox owns Twelve O'Clock High and I'd say the possibility of their releasing that on DVD is close to zero. They also have locked up on their dusty shelves the TV western series I want the most, The Monroes. (It was the only TV series in which Ben Johnson had a regular role.)
A DVD-R is burned, not pressed.
You can tell when it's a DVD-R because it will be purplish in color. A pressed DVD is silver.
If you make a DVD recording at home, that's a DVD-R. They can fail, though companies like Warner Bros. that release their old movies on DVD-R have developed proprietary software that makes their DVD-Rs far more reliable than the DVD-R you burn at home.
Any DVD or Blu-ray player these days should have no problems playing a DVD-R, especially since so many companies now burn their discs instead of pressing them. (Warner Archives, Sony Classics, Fox Cinema Archives, VCI, etc. etc.)
All those TV shows you listed are bootlegs. Some guy is sitting at home making DVD-R copies of shows he either recorded off TV, or perhaps has made from 16mm copies he collected. He's committing a crime by selling these programs.
That said, I will admit to buying bootlegs when I really want to see something and it's not available any other way. If it becomes available from the official source, I will then buy it because it's going to look better than the bootleg and because I want to make up for the loss they suffered when I bought the bootleg.
From the videohelp.com forum:
"Pressed" discs are stamped out in a plastics-molding stamper. The data patterns, represented as a series of pits and lands (a "land", BTW, is simply the absence of a pit in a particular spot), is permanently molded into the plastic during the stamping process. Basically, its the same process that was used to make vinyl records (and CD's, for that matter), just ramped up a few orders of magnitude in precision. After the plastic has been stamped, it then gets coated (via vacuum deposition, if I recall correctly) with a few-atoms-thick layer of reflective metal, and another layer of plastic is bonded onto the top. During playback, the laser's reflection angle is subtly altered depending on whether there's a pit or a land in front of the beam, which causes the reflection to hit or miss the detector. These hits and misses become a binary data pattern.
"Burned" discs, on the other hand, do not have the data permanently embossed into the plastic. They are produced similarly to a pressed disc to start with, in that they are molded in a plastics stamper, but instead of a pattern of pits and lands representing data, a pattern called the "pregroove" is stamped into the plastic. The pregroove's primary function is to give the write laser something to track as it writes the spiral data pattern from the inside out. In between the bottom layer of plastic and the reflective metal layer, there is a layer of photochemical dye which responds to a particular frequency and power of laser light. During the write process, the drive actually does "burn" the dye, causing it to become opaque in spots where the laser hits it. This pattern of light and dark spots then mimics the pits and lands of a pressed disc during playback, by blocking and unblocking the laser reflection. (The detector doesn't know if the beam isn't returning due to a dark spot or an altered reflection angle, all it knows is it doesn't see the return beam.)
