Just out of interest, how difficult would it be to create a 64bit version of the Spectrum BDA drivers (not that I currently own a 64bit system or OS)?

I'm not really sure. I don't have a 64bit system to develop/test on so I wouldn't be able to even try at the moment.

Spectrum

I have ported my own BDA driver (for various TechnoTrend cards) to 64-bit, both IA-64 as well as AMD64...

...but it was no use - when I went to install my driver on an AMD64 box, is turned out that there is no BDA support in AMD64 Windows!. The INF file "BDA.INF" which is supposed to install the BDA support has been emptied out to become a "dummy", and crucial files are missing, most significantly BDASUP.SYS. Since a BDA minidriver directly links to that file, the driver binary will not even load without it

I have submitted a bug report to Microsoft requesting BDA support to be added to 64-bit Windows, but it seems to be open whether it'll happen or not. So it's possible that there simply won't be digital TV on 64-bit Windows...

Well they have to finish writing the 32bit support first I guess

Save them having to port it twice. Although I don't see why it would be a big deal... ?

More problems ~ http://theinquirer.net/?article=19112

Oops, time for an update: Full BDA support was added to Windows XP x64!

And it works pleasingly well: Once a 64-bit BDA driver is installed, you can continue to use 32-bit BDA applications on it, no modifications required. So you really only have to worry about getting a 64-bit BDA driver. Once that is taken care of, you can still use your favorite 32-bit BDA TV application.

Of course, 64-bit BDA TV applications would be even nicer, but there's a catch: 64-bit applications can only use 64-bit MPEG-2 decoders, and there are no such things available yet...

Cool. So as I understand it you can run a graph of either 32 bit or 64 bit filters (but not mix and match). So does the 64 bit BDA architecture supply both 32 and 64 bit NetworkProviders etc ? And from what you are saying the 32 bit NP will talk to either 32 or 64 bit drivers.

Yes.
Yes. Alle the user-mode BDA components are available as both 32-bit as well as 64-bit binaries, so both 32-bit applications as well as 64-bit applications have an environment in which all BDA DirectShow filters (software filters as well as device filters) are available.

There is one little exception, though: The Teletext decoder filter (WSTDECOD.DLL), was not ported to 64-bit, but at least I could convince Microsoft to ship the 32-bit version with Windows XP x64. So only 32-bit applications can use Microsoft's builtin Teletext decoder. While this is not a BDA component, it can be used to display Teletext transmitted over DVB, of course - but not in 64-bit applications
Umm, no. There are only 64-bit drivers in Windows XP x64...

And the 32/64-bit "abstraction layer" is a bit below that: The NP employs the IBDA_* device interfaces to communicate with the driver, and those in employ KSPROXY. And from what I understand, KSPROXY then calls DeviceIoControl() to actually communicate with the driver. And the DeviceIoControl() API can be used by both 32-bit as well as 64-bit applications to communicate with the 64-bit drivers, so it is really DeviceIoControl() which implements the "abstraction layer".

Thanks for clearing that up, my thinking was a bit muddy Makes more sense now

Would someone please share their 64bit VisionPlus drivers? I'd like to play with 64bit Windows XP.

There are none for the VisionPlus that I am aware of ~ Unless Spectrum has ported his...

IIRC RobertS wrote some for a couple of cards in Europe some time ago (and has apparently ported them ~)

And the noticable advantages are?????