Messages in this thread | | | From | Markus Gutschke <> | Subject | Re: Any work on drivers for TV tuner cards? | Date | 15 Nov 1996 22:17:35 +0100 |
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henning@pong.iconsult.com (Henning Schmiedehausen) writes: > There is a driver for a simple (very cheap) TV tuner card on Sunsite. > I have such a bugger (about $50) in my PC @ home as cable TV. There is > no PiP, you have either TV picture or video screen, no Frame grabber > or stuff. Just a computer controlled TV. The card was a surplus item, > I'm not sure if you can still buy it. The driver is called > vt-1500something, it was written by some german. The driver is ^^^^^^^^^^^ That would be me :-)
> completely Userspace, no Kernel stuff required.
As there seem to be frequent requests for this information, I assembled a standardized message that answers most common questions. As this is becoming off-topic, please do not follow-up to the list!
Markus
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Hi,
the VT1500 is a very old card that despite its technical merits has been discontinued quite a while ago. It appears that the only cards that you can still buy, are from the German distributor (Behavior Tech Corporation Germany) that still has a few of them left. Price used to very competitive at about US$40 (60,-DM), but when I discovered that you could still buy them and announced this information on Usenet, the price jumped up to US$100 (150,-DM). (there might be slight differences depending on where you want to ship the card and on whether you have to add tax). Nonetheless, this is still a good offer and I would suggest for you to get one, as it gives excellent image quality and usually works with all kinds of hardware (no special requirements on graphics cards or monitors).
The only thing to watch out for is the requirement of a full-sized 8bit ISA slot. The card is quite big and might not fit into all motherboards if for example your CPU+fan is unusually high/big. Naturally, this does not apply to modern ATX motherboards. The card occupies one I/O address at either 0x200 or 0x300 and does not require any interrupts. It has connectors for RF (radio frequency style video signal, also known as antenna input), FBAS ("pure" video signal), audio in, audio out, and VGA in/out. If you connect the card using the RF connector there is a frequency range from 48MHz to 855Mhz, so this should give ample opportunities even when connecting to cable TV.
The card uses a couple of Philips chips to convert a PAL (50Hz interlaced, 15.625kHz scan frequency, European standard) or NTSC (60Hz interlaced, 15.75kHz scan frequency, American standard) signal to a standard VGA (50 Hz non-interlaced, 31.25kHz; or 60Hz non-interlaced, 31.5kHz) signal. There are a few very old monitors out there that cannot properly synchronize to 50Hz/31.25kHz; if you are as unfortunate as to owning one of these, than you wont be able to use the VT1500 card for receiving PAL signals. Nowadays, this should not be a problem any more and all VGA compatible monitors that have been built during the last couple of years will be able to display these signals.
Theoretically, it should be possible to receive SECAM (French standard) signals with the VT1500, but I do not have sufficient programming documentation for adding support to he driver software. Due to lack of a SECAM source, I have never tried to do this but you can probably receive SECAM images in black/white as all of these standards (PAL/NTSC/SECAM) basically just differ in the way that they encode color information.
Even though the tuner does cover the frequency range that is commonly used for FM radio (88Mhz thru 108MHz), you cannot use it to receive radio stations. TV stations require approximately 5MHz of bandwidth; this includes a sound carrier at a fixed offset from these 5MHz. In order to cope with possible random frequency shifts, the card allows for AFC (automatic frequency control) and AGC (automatic gain control) while applying a very wide band-pass; this is perfect for TV reception, but disastrous for FM radio reception. It means that you will receive multiple radio stations superimposed on each other.
The card does not have framegrabber capabilites and therefore runs in fullscreen mode only (occupying one of Linux's virtual consoles). The underlying hardware can cope with both PAL and NTSC, but the on-board tuner is not as versatile. The cards that you get from BTC Germany have a PAL tuner which is fine for TV reception in Germany (and probably most other parts of Europe except for France), but if you live somewhere else (e.g. in the US) you need to find an external tuner that you can connect to the board.
Sometimes cable TV boxes, satellite receivers, or VCRs come with an FBAS output that you can use for this purpose. In Europe, most TV equipment comes with SCART plugs and you often can find an FBAS signal on one of its pins. In other parts of the world, there might be equipment with RCA jacks that are labeled "Video Out"; this should give you the FBAS signal. Make sure that you do not confuse it with the RF signal, which is an FBAS signal superimposed on a radio frequency carrier; this is what you need the tuner for.
If you order from the German distributor you should try to get the more recent Revision 2.1 board. The older Revision 2.0 board has a defective tuner and you always have to provide an external FBAS signal. The Revision 2.1 board has the PAL tuner. Actually, this is not that much of importance to you, if you intend to use NTSC anyways; so if everything else fails, you could probably still go with the Revision 2.0 board.
It has been a while that I ordered from BTC and thus I do not know which method of payment they accept. You probably have to call them or send a FAX. As far as I can tell, they do not have an e-mail address. They might agree to COD, but most likely you first have to send a money order or something of that kind.
Disclaimer! I do not have any affiliation with Behavior Tech Corporation other than owning one of their VT1500 cards and having written a Linux based device driver for this card.
I would very much appreciate, if you told me about any success (or failure) in obtaining the VT1500 card. If you use my software, I would like you to send me a postcard from your hometown --- it is quite fun to have all these postcards telling you how far your software spread ;-)
Good luck,
Markus
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USA: Behavior Tech Computer Corp 4180 Business Center Drive Fremont, CA 94538 Tel: +1-510-657-3956 FAX: +1-510-657-3965 Netherlands: Tel: +31 10-462-1650 FAX: +31 10-487-3552 France: Tel: +33 74 95 58 58 FAX: illegible sorry Germany: Behavior Tech Computer Corp. z.Hd. Markus Gabriel Wellastrasse 14 36088 Hunfeld 1 Germany Tel: +49-6652-73813 FAX: +49-6652-74312
-- Markus Gutschke Internet: gutschk@math.uni-muenster.de Schlage 5a D-48268 Greven-Gimbte Germany
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