I want to tell about these four categories in an uncharacteristic format for me “based on materials from the Internet”. You can get rare devices and disks from this list, but I just don't have that much money for a hobby. Fortunately, they were described in some detail by wealthier collectors. Before starting, I want to share this thought. It seemed to me that the key to the long-term success of any technology is a certain margin of safety. In the case of a storage medium, I mean the backlog for the subsequent expansion of functionality. For example, after stamped CDs, there were writeable once, and then rewritable. The technology itself has evolved to modern Blu-Ray media with a storage capacity of over one hundred gigabytes per disc of the same size.
The laser video disc appeared too early to become mainstream, but it had a margin of safety. For digital sound, stereo and multichannel, and then for recording video in the "almost FullHD" format, and for data. Its analog nature and large size did not allow it to become a popular multimedia storage medium for computers in the nineties (it became a compact disc). But there were attempts, back in the eighties, not long before the CD-ROM, but in fact from a completely different era. And these attempts were very interesting.
Previous article about laser video discs with practical experience and impressions.
I keep a diary of a collector of old pieces of iron in Telegram .
Squeeze LD
Let's start with a simple game: Squeeze LD discs. Since the laser videodisc eventually became the format for wealthy moviegoers, quite a few films were released with a "theatrical" aspect ratio, in a wide format. And this is in the days when the standard TV was a box with an aspect ratio of 4: 3. A wealthy moviegoer could purchase early widescreen TVs or install a projector (usually a huge chest with three pipes). Even in this case, the vertical resolution of the frame was lost. For example, the aspect ratio of Terminator 2 movie is 2.39: 1. Vertical frame resolution in PAL standard - 576 lines, aspect ratio 4: 3. It turns out that the frame from "Terminator" in the theatrical version should occupy 321 lines vertically. Everything else is horizontal black bars.What if you stretch the frame vertically using the full resolution of the frame (576 lines in PAL or 480 in NTSC) and compress it during playback? This was done on Squeeze LD discs.
In fact, the technology of shooting an anamorphic image on film was used , only there specialized optics are responsible for stretching and compression.
The LD film database knows only about 34 releases in the Squeeze LD format. The technology came too late and provided too little improvement in image quality to become popular. On players and TV, which cannot “pull” the picture, it broke compatibility. In general, it did not take root. Due to the small number of editions, Squeeze LD discs are now expensive or very expensive.
Hi-Vision and MUSE format
But the artifact value of the Squeeze LD cannot be compared to the Hi-Vision discs. Introduced in 1993, Hi-Vision was essentially the first medium for high definition video. 10 years before Blu-ray and HD DVD. Five years before the release of yet another rare D-VHS format . Long before the mass distribution of TVs and TV broadcasting in HD format.
The history of Hi-Vision is detailed in the video on the Techmoan channel. The embed above is the first part, but here you can find the second. Hi-Vision is a trademark for the media. The video codec standard is called MUSE , and it was also used in Japan for early analog (!) High definition television broadcasting. Image parameters (some technical data is available here): resolution of 1035 vertical lines (quite a bit less than 1080 lines in the modern FullHD standard), 30 frames per second, uncompressed signal required a bandwidth of 30 megahertz. After compression, a signal with a bandwidth of 8.1 megahertz was stored on the laser disk, slightly more than the standard ~ 6 megahertz for conventional LDs. This was done by improving several parameters of the media: the speed is slightly higher (up to 2700 rpm versus ~ 1800 for the standard LD), the data is recorded a little denser.
From the same video by Matt Techmoan I will give a comparison (ok, slightly shaken by YouTube) of a regular LD and a Hi-Vision release. There is a difference, but it is not outstanding: in addition to the capabilities of the standard, it also required correct transfer, scanning the source in high resolution. In general, everything that was not yet in the mid-nineties. It never ceases to amaze me that at the same moment when my parents were enjoying the first tape recorder, someone (very rich even by Japanese standards) was watching a movie in high definition.
A close to ideal example of HD video from the nineties is shown above. This is a 1993 recording, but later re-released in digital format, on a D-VHS cassette. Compared to the capabilities of modern HD camcorders, and even smartphones, the picture is slightly soapy, but still better than standard definition analog video.
To watch a high-definition laser disc today, you will have to pay a lot of money. 3-5 thousand dollars for a working turntable, or a thousand for a non-working one if you want to play renovated roulette. The Techmoan player broke two times, the last one fatally. Moreover, the player will simply not show you the movie, you also need a separate MUSE format decoder - in Japan it was used both for viewing Hi-Vision and for decoding a TV signal from a satellite. It is widely believed among fans of the laser disc that the Hi-Vision player reads even regular publications better, due to the laser emitter with a shorter wavelength (670nm versus 780nm). Yes, the laser parameters are almost the same as the DVD format released four years after the laser disc (650nm there). Finally, if you bought the hardware and it works for you, you need movies. The LDDB database containsinformation about 167 releases. On eBay, these discs sell for about $ 300.
Recordable laser discs
Here, finally, laser discs begin to approach the computers of those times. But not in all cases. Recordable laser discs were most often used to store analog data - the same images or video, not digital. Two digital formats are mentioned here : Philips LV-ROM and Pioneer LD-ROM. Using different file systems, these disks could hold, respectively, up to 324 or up to 540 megabytes of data per side. Which, given the size of the media, is somehow small. All recordable incarnations of a laser disc have one feature: they were used only in a professional environment, they cost a lot of money, and now information about them needs to be collected literally bit by bit.
A popular description of yet another recordable format, this time Sony's CRVdisc, can be found in Techmoan's video. He was not lazy and found a recording device, as well as discs. This setting assumes work with a video signal, and is not connected to a computer for data transmission. CRVdisc parameters are slightly worse than those of the factory LD in CAV format: 36 or 43 thousand separate frames, that is, 20-24 minutes of video. The video provides examples of use: an image library, such as an ancient digital catalog in a museum. Or a dynamic "backdrop" for a TV broadcast, into which an image from the presenters of TV programs is pasted. In general, a recordable laser disc was justified where it was required to record something once, and then regularly reproduce it without degradation, and with a sufficiently high quality. A kit similar to the one Techmoan tested isat the time of publication of the articlesold in the Netherlands for only 3500 euros (new!). Discs (recordable, let me remind you, once) must be purchased separately. There is exactly one offer on eBay now: two used (!) Discs for 150 euros in Germany.
Domesday project
The history of the Domesday project begins more than 900 years ago, when in medieval England was carried out either a population census or an inventory of the resources of the national economy. The tome with the results of the census is called " The Book of the Day". In the title of the book, the semantic emphasis is rather not on the biblical" last judgment ", when everyone will be rewarded for their actions, but on information about these very actions. This is a valuable source of historical data, and many years later, in the eighties of the last century, they decided to reproduce the concept using the most modern technologies.Information about the modern life of the United Kingdom was collected, videos about the then life were recorded, an accompanying text was written. BBC Domesday Project (in honor of the book) and was available on the system from a BBC Master computer made by Acorn and a Philips laser player.
That is: a computer with an eight-bit MOS 6502 processor , 128 kilobytes of memory. The laser player is controlled via SCSI interface, both data (up to 300 megabytes on the side) and video / images are stored on the disks. Text and computer graphics are superimposed on an analog picture, and all this is displayed on a monitor. The video above shows the complete system at work, including the incredible implementation of what we now call Google Street View. Very cool: a real multimedia interactive that was made in 1986, five years before the distribution of multimedia releases for regular IBM PCs on CDs. Given the incredibly poor video and picture quality on the MPC CD-ROM, the Domesday Project even had a slight edge in quality.
Yes, but at the same time the project is a typical example of premature digital obsolescence. A bet was made on the computer architecture that was already outdated at that time. Non-viable storage medium for digital and analog data. Even the programming language ( BCPL) - and that one is outdated. At the same time, you cannot just take and transfer the code base to a modern programming language, or run it in an emulator: the whole project is tied to a laser disk with analog information. It is not enough just to digitize it, you still need to restore the logical sequence: under what circumstances the program reproduces this or that picture or video, referring to the required area on a certain disk (there were several of them). At the beginning of the 2000s, it became clear that when the last specialized LD-player died of electronics or laser, the Doomsday project, in all its interactive completeness, would be lost.
Attempts were made to recreate the project on the web, which in themselves quickly became obsolete, lost due to the death of the author. Content sharing initiatives were thwarted by copyright. In short, we can say that society has faced great difficulties in preserving the modern heritage, consisting of images, text, code, iron. The difficulties were not only technical, but also legal. All this applies not only to the Domesday project, but also, for example, saving information from the web and many other computer archiving tasks. I see a certain irony in this: there are big problems with the computer-multimedia heritage of 34 years ago, and the thousand-year tome - please, available, take it and read it.
Non-standard digitizing of laser discs
And that brings me to the final laser video disc story for today. The Domesday86 project tries to solve all the technical (but not legal) issues of keeping the BBC Domesday Project. The end result should be a faithful emulation of the original code on modern hardware. The biggest difficulty, as I said above, is pairing the software with hardware in the form of a laser disc player, or with an LD-player emulator, which will return the image that is required upon request. The project site has a lot of technical information about the original hardware. I was especially interested in the Domesday Duplicator project . The task of its authors is to digitize video and graphics from Domesday laser discs with the highest quality.
For some of the materials, there are sources from which LD was printed - on videotapes with inch tape. They have been digitized, but it is also interesting how the original videos and pictures are saved on laser disks. That is, it is not enough to capture the video signal, you need to somehow record the analog data in its entirety, for example, with metadata and indexing.
That's why the Domesday Duplicator was developed. This is a 10-bit ADC that captures a 20 megahertz bandwidth (13 MHz is sufficient for LD data with plenty of headroom). The device connects to a USB 3.0 port and, on the other hand, directly to the RF Out pin of the laser player. Thus, the analog circuit of the old device does not participate in signal processing, the separation of data into sound and image, signals of brightness and color, occurs already in digital form. "Rip" one side of the laser disk (half an hour) takes more than 100 gigabytes.
Open source software was developed for processing raw data, the result of which is shown in the picture above. On the left is a normal video capture using a consumer capture card. On the right is the processing of raw data read by the laser. The most interesting thing is that this technology is applicable to almost any laser disc player, and to any disc. In another life, I would definitely take up such digitization, for the sake of experiment. It's so interesting: to extract a video signal from an imperfect (by modern standards) media with a quality that no ready-made player can provide. But no, I'll probably limit myself to watching movies from old discs, on an old turntable, and on an old TV. Nevertheless, I can't help but admire the tenacity and fanaticism of the authors of the Domesday86 project. It is thanks to such people that the rapidly aging, rare,inaccessible technologies can find a second life. This is such a pinnacle of retro hobby. It's one thing to spend a lot of money playing rare HD releases for your own pleasure. Another is to study the retro format thoroughly and create something new for it by sharing with the community. If I have the strength and knowledge, I will definitely do this, but it seems with another retro format - my favorite minidisc.