I had the same issue my Tandy 1000 TL/2. You need a XT-IDE BIOS padded with 16K of hex FF bytes in the beginning of the file in order for this work. This is documented in Lo-Tech's XT-CF FAQ. Look for the part where it mentions a Tandy 1000 RL. A preconfigured BIOS file is provided by them that you can download. https://www.lo-tech.co.uk/wiki/Lo-tech_ISA_CompactFlash_Adapter_FAQ#What_BIOS_does_the_Card_Use.3F You will need to change the jumper on you card to set the BIOS to D800, flash the BIOS using their Flash utility and then change the jumper back to C800. You will then notice the BIOS will actually start at CC00 instead of C800. You also need to make sure to run the Tandy 1000 TL/2 setup program and change the boot option from ROM to DISK. Everything should be working after doing this. This removes the conflict with the built in hard drive controller BIOS.