3 ms·

SD cards have a physical switch you can flip for read-only.

• ohWhatever 13y ago
  Yeah and my old Intel 486 Gateway 2000 had a Turbo button. What's your point?
• simoncion 13y ago
  The switch is electrical and advisory. The SD card reader is free to ignore it. Search for "Bootable SD Card Method" here: http://chdk.wikia.com/wiki/Prepare_your_SD_card http://chdk.wikia.com/wiki/Prepare_your_SD_card (I have a Canon camera that runs CHDK. Those instructions work, and the camera can write to the SD card.)
• nitrogen 13y ago
  The SD card switch is actually read by an external physical sensor (a tiny button like the write-protect buttons inside of ancient 3.5" floppy drives), at least on most SD cards. I had an SD card whose switch wasn't quite thick enough to trigger the writability sensor of an SD card reader, so I had to wrap it in tape.
  • nwh 13y ago
    In a completely unrelated area, you just saved me a pile of effort and time with that tape trick. Kudos.