Re: Any work on drivers for TV tuner cards?

Markus Gutschke (
15 Nov 1996 22:17:35 +0100 (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!


re -- cut here -- cut here -- cut here -- cut here -- cut here -- cut he


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

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,


re -- cut here -- cut here -- cut here -- cut here -- cut here -- cut he

Behavior Tech Computer Corp
4180 Business Center Drive
Fremont, CA 94538
Tel: +1-510-657-3956
FAX: +1-510-657-3965

Tel: +31 10-462-1650
FAX: +31 10-487-3552

Tel: +33 74 95 58 58
FAX: illegible sorry

Behavior Tech Computer Corp.
z.Hd. Markus Gabriel
Wellastrasse 14
36088 Hunfeld 1
Tel: +49-6652-73813
FAX: +49-6652-74312

Markus Gutschke            Internet:
Schlage 5a
D-48268 Greven-Gimbte