This issue has been driving me to my wits end. A few months back I purchased an SD to IDE adapter to use instead of a hard disk on my DECpc lpv+ 486sx-25 pc I’ve formatted the drive and I can copy and delete files, but when I try to execute programs I get a flashing cursor and “Not ready reading drive C:”. I’m unable to boot from the drive even though I ran fdisk and format /s. The SD card itself is 256mb and well below the LBA limit, and the geometry is detected by the BIOS without issue.The adapter is verified to work on my pentium machine with no issues. Any ideas? This is driving me crazy.