It has integrated DC remove filter and allows to setup any possible sample rate.
This ExtIO works through librtlsdr.dll from OSMOCOM (librtlsdr.dll should be renamed to rtlsdr.dll).
I wrote it because existing ExtIO_RTLSDR for some reason doesn't works in Direct Sampling mode with SDRUno. So, there is no way to receive MF and HF stations (0-14 MHz) with SDRUno and RTLSDR. This ExtIO works ok in such mode. Also I added DC remove filter, because it is missing from SDRUno.ExtIO, you can enable/disable it from ExtIO settings window.
It is written in C#, so I named it ExtIO_RTLSDR#

Also it means, that it requires .NET Framework Runtime 4.0. Usually it is already present on windows operating system, but if it is not, it should be installed from this page: https://dotnet.microsoft.com/download/d ... work/net40
Bug reports and suggestions are welcome.
This is 32 bit version, if you're needs 64 bit ExtIO version, please let me know, I will complile it for 64 bit.
Since I don't know 64 bit software which uses ExtIO, I don't know how to test it. Please let me know about such software.
I included rtlsdr.dll compiled from OSMOCOM source (librtlsdr + libusb v1.0.22-rc4).
But you can replace it with other versions, just rename librtlsdr.dll to rtlsdr.dll and place near ExtIO_RTLSDR_u8.dll.
For HDSDR, you're need to place this file near HDSDR.exe, also rtlsdr.dll should be placed near ExtIO_RTLSDR_u8.dll.
For SDRUno, you're need to place it into My Documents folder.
You can use several ExtIO drivers, just place it together and HDSDR/SDRUno will ask which one should be opened at startup.
PS: also I wrote similar ExtIO for HPSDR protocol (to use it with Hermes transceiver), but it is still a little buggy. If you're interested, I can share it.
UPDATE: the latest version is 1.1.1.7 is here: viewtopic.php?f=1&t=4710&p=11796#p11796