The Virtual Televisor project is now essentially complete. Image quality using the AC-coupled interface is now at a high technical standard and Version 1.0 of the DOS-based software is scheduled for the next week or so. At this point I am beginning a fundamental re-organization of this project site from experimental/development to support for those duplicating the project. As a result, some material, such as the discussion on  Why Use a Computer for NBTV Image Display  has been moved to its own page.

The samples shown below are unretouched images, obtained using the software's Save Image function, from various image sources.
 
 

I received some inout from one source that felt that I hadn't done a very good job in setting up the aspect ratio for the NBTV images in the Virtual Televisor software. This subject is discussed at greater length on the new  Virtual Televisor Aspect Ratio  page. Bottom-line is that the VTV aspect ratio is just fine.

Chris Lewis' Virtual Televisor

Chris Lewis, based in the UK, was the first to construct one of my ROMScanners and he was just as adventurous with the Virtual Televisor. His completed interface, along with a sample picture from his ROMScanner, are shown above. The software support for saving images is very valuable for showing off your handywork or for getting trouble-shooting advice is there is a problem.

One of the problems with setting up an NBTV display is the small size of the image when a scanning disc televisor is used for display. Very small image display sizes are also a feature of some computer software that is available. The example shown above for the NBTVView program is a nice image when displayed in its normal size (about what is shown here for a 640 x 480 display to about the size of a postage stamp with  1024 x 768 screen resolution), but cannot easily be enlarged for viewing by a larger group. NBTVView is a fine program, but cannot render images large enough for comfortable viewing on the workbench or in a group setting.

To give you a realistic appreciation of the actual size of images displayed with the Virtual Televisor (VT) program, the simplest thing is to simply show you:

To get this picture, I had to perform some image manipulation. To get a reasonably exposed image of the computer LCD monitor screen, I set the camera up on a tripod and shot the picture using available light. Unfortunately, the rest of the image was quite dark, so, without moving the camera, I shot a second picture using the flash. The reflection of the flash wiped out the image on the monitor, but the other elements of the picture were greatly improved. I then pasted the monitor screen from the first image onto the washed-out screen on the second picture. While I had to manipulate the image, it gives a fair representation of what you would see were you standing in my radio shack. The VTV interface is the dark-colored unit on the left corner of the desk. The light-colored cabinet on top of the interface is a ROMScanner. The size of the Virtual Televisor NBTV image relative to the computer screen is well-illustrated in this photo. The system was displaying NBTVA disk 2 and I took the picture during Jeremy Jago's interview. If you want to watch 32-line images without eyestrain and flicker, need a robust image display while working on the bench, or want to display NBTV at a meeting or demonstration, the Virtual Televisor system may be a rewarding and practical project.

While development of the DOS Virtual Televisor software for the interface will serve for die-hard experimenters, there is no doubt that a Windows-compatible version of the software would greatly increase the appeal of the project. The DOS-based software will solve the problems of how to communicate with the interface and process the data, but putting that capability to work in the Windows environment will require the help of a Windows-savvy programmer. If you have the programming skills and an interest in NBTV, I invite your help and collaboration. You can e-mail me at any time if interested.

If you are using a Windows-based PC and want the absolutely simplest approach to viewing NBTV, you really should visit Gary Millard's web site. His NBTV - The Big Picture does everything the Virtual Televisor can do with absolutely no need for interface hardware. It will do NBTV from a sound card and directly from an audio CD or WAV audio file and the site also contains software to covert AVI video/audio files to NBTV, solving your camera problems. I pursued the Virtual Televisor project because it was fun and educational - not to mention a challenge. If you want to skip the hard stuff and move directly to quality NBTV viewing, try Gary's software!

Prior to constructing an interface or downloading the software, there are some critical points of which you should be aware:

• There is no point in downloading the Virtual Televisor DOS software if you do not intend to build an interface. The software will not run unless connected to a working parallel port interface. Even if it would run, there are no useful functions it could perform in the absence of an interface.

• There is no point in building an interface unless you have or will a computer that is fast enough to run the software. The Virtual Televisor was developed on a 2 GHz Dell Pentium and obviously works well with that system. Tests with other computers suggest that a Pentium-class machine is probably the absolute minimum system that will run the software. All current "fast" systems can certainly run the software, but older machines (486, 386, or 286 systems) will not. It may be possible to tweak the software over time to lower this "speed limit" and, if that happens, the results will be posted here.

This is a new page, describing the basic operation of the interface for those who do not choose to download the entire construction package.

The link shown above will take you to the construction page, containing lots of useful information and a link to download a complete 25-page construction manual.

This page will contain complete instructions for downloading, installing, and using the Virtual Televisor for DOS software.