Updating GDEMU

GDEMU firmware (internal operating software) can be updated by placing a special file on the SD card. For the procedure to work properly you must follow these instructions to the letter:

IMPORTANT: DO NOT reflash your device at the very first sign of trouble. In 99.99% of cases the problem is something you did (or didn’t do) and not a FW bug.

  • Extract the firmware file and rename it to “GDEMU.fw”
  • Place the file in the root folder of the SD card
  • Move the write protect tab at the side of the card to “Lock” position
  • Insert the card into GDEMU socket with Dreamcast powered off
  • Power on the console, status LED will start blinking very quickly
  • Wait until LED blinking pattern changes to 1/2 second on, 1/2 second off
  • Power off Dreamcast, remove the card, unlock the tab
  • Remove the file from the card to avoid accidental update

IMPORTANT: If at any time during firmware update status LED stays completly on or off, or blinks in unexpected pattern, it means an error has occured. Retry the procedure, use a different card if the problem persists.

Latest firmware: 5.15.0



  • Internal changes
  • Newer compiler used

5.14.0 (not released)

  • Internal changes
  • Limited support for long names  (ASCII only) in filenames


  • CCD parser properly detects CD-ROM XA on multisession discs
  • CCD images with scrambled tracks will now work (with small speed penalty)
  • CCD and CDI images with multiple track indexes are no longer rejected
  • Added subchannel scanning for MCN/ISRC data (can be disabled in INI file)


  • NBA Hoopz booting issues resolved


  • Fixed streaming issues on CDDA-heavy games
  • Fixed regression that broke plain ISO images
  • Multi-session MDS/MDF images should now work


  • Audio is no longer slightly muted on some Dreamcasts


  • Fixed CDDA playback broken in 5.8.2 for some games


  • Initial timing fix for Stupid Invaders


  • Fixed button API broken in 5.8.0
  • Option for jumping to selected image on system reset


  • Image limit raised to 9999, folder prescan removed
  • Initial support for high speed mode on SDV2 / SDHC cards


  • Fixed erratic behaviour of the button API on some units


  • Option to disable strict image integrity tests via INI file to allow oversized media for undub / translation projects
  • Image limit raised to 64
  • Initial support for up/down button emulation via API


  • Some fixes for Bleem – beta now boots and works
  • BIN image support for PSX games (single track only, raw sector format)
  • CDDA pause/continue issues resolved
  • Lid open and disc detect time can now be specified in INI file


  • Initial revision for v5 models

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