Release verification 0.95 (batch #2) instructions and tips

This is the home page for our effort to validate the MEGA65 firmware and system software for the Q4’2022 shipping batch, known as “release 0.95.” If you have a batch #1 MEGA65 (“R3”) or a Dev Kit, or a Nexys 4DDR board, you can help!

We especially need people to test with a batch #1 MEGA65 (“R3”). If you have a JTAG interface and a clean SD card, you can set up your MEGA65 to most closely resemble a factory install, with the release candidate core in slot 0. If you do not have a JTAG interface, you can still test the firmware and system software with the core in slot 1.

Current release candidate

Latest release candidate SD card contents (possibly newer than in the release candidate archive):

There are also test distributions for R2 and Nexys 4DDR boards, though issues specific to these boards will need to be considered separately from this release.

Known issues

See for major known issues being tracked for this release.


  • “having trouble running GEOS65 in the past please try to mount GEOS65.d81 from clean ready prompt oder set it to default image in config”

How to report issues

Please check whether a bug has already been filed before creating a new issue! This helps us with de-duplicating and triage. When possible, comment on an existing issue.

If you have found a new issue with the core in slot 0, the Onboarding tool, the Config Tool, or the Flasher menu, click New Issue on that page to associate the new issue with the release milestone.

To report an issue with the release prep disk, visit mega65-release-pre Github Issues, then click new Issue. It will be triaged to the appropriate repo and priority for release.

Requested tests

We are currently focusing on: Testing everything!

Note: first flash your MEGA, then do the other tests!

  • If you have a JTAG connector:

    • (Consider doing the slot 1 tests, below, before installing the core into slot 0.)

    • Flash the COR into slot 0. (See instructions below.)

    • Test the configuration utility.

      • Hold ALT while powering on.

      • Test RTC setting. See updated date formatting.

      • Test MAC address: press R to randomize.

    • Test the onboarding utility.

      • From configuration utility, Exit and Reboot to Onboarding.

      • Test RTC setting. See updated date formatting.

    • Test the core utility.

      • Hold NO SCROLL while powering on.

      • Try installing different cores in different slots.

      • Press HELP to get version information. (If HELP asks for a file, you have an old version of the flasher.)

      • Try to break it!

    • Press and hold random keys while powering on.

  • Install the COR into slot 1.

    • Copy the COR onto the SD card.

    • Hold NO SCROLL while powering on to enter the core installation/selection menu.

    • Press Ctrl + 1, then select MEGA65R3.COR and follow prompts to install the COR in slot 1.

  • With the COR in slot 1:

    • Hold ALT while powering on to access Configuration. It should say v1.0, using the Configuration menu from the slot 1 core.

    • Hold ALT while powering on to access the SD Card utility. It should say v0.24, using the SD Card menu from the slot 1 core.

  • Prepare a fresh SD card using the sdcard-files provided in the release candidate download.

    • Linux and macOS: Use the script to install the files onto a previously-prepared SD card. (This copies the files with the recommended defragmentation technique.)

    • If you have a full-size SD card that you’re willing to fully erase:

      • Open the case and insert it into the internal SD card slot.

      • Use the SD Card utility (from the Alt boot menu) to prepare, erase, and install the system software in the internal slot.

      • Move the SD card to your PC and install all files from mega65-release-prep.

      • Eject it from your PC and reinsert it into the internal SD card slot.

      • This (plus the core in slot 0) is the complete launch configuration for batch #2.

  • Test all programs on the MEGA65.D81 disk.

  • Test GEOS65.D81 (included in mega65-release-prep).

  • Try the Turrican Engine Demo by Shallan.

  • Test other programs that you use, develop, or own.

How to flash a core to slot 0

You must use the m65 command line tool (the “refactor” version). Using M65Connect will currently not work!

  1. Copy the latest release COR file to the SD card, using a short filename such as R3RC1.COR.
    Make sure that you also have all required files on your sdcard, as using jtagflash needs a running MEGA65 System!

  2. Turn off your MEGA65.

  3. Open the MEGA65 case.

  4. Set DIP switch 3 to ON. (Switch 1 is closest to the front of the case. “ON” is to the left.)

  5. Make sure your JTAG interface is connected to the MEGA65 main board, and to your PC.

  6. Turn on your MEGA65.

  7. MEGA65 will notice that DIP 3 is on. Press Run/Stop when prompted.

  8. The monitor appears. Press x then Return to exit the monitor to the READY prompt.

  9. Use m65 tool to push the BIT file via JTAG to your MEGA65. If this fails, stop here.
    m65 --bitonly mega65-reltest/mega65r3-2022XXYY.ZZ-abcdefg-89fdecb.bit

  10. This will give you an output like:

    1 2 3 4 5 6 ograf@vlad$ m65 --bitonly mega65-reltest/mega65r3-2022XXYY.ZZ-abcdefg-89fdecb.bit 2022-09-23T08:35:35.074Z NOTE MEGA65 Cross-Development Tool 20220919.23-refact-bf8ded4~ 2022-09-23T08:35:35.112Z NOTE selecting device /dev/ttyUSB1 (Digilent; 0403:6010; 251633006E10; 03636093) 2022-09-23T08:35:35.228Z NOTE fpgajtag: Starting to send file 2022-09-23T08:35:38.759Z NOTE fpgajtag: Done sending file 2022-09-23T08:35:38.776Z NOTE Bitstream loaded

    Note the second line: selecting device /dev/ttyUSB1
    What is printed there is the device you need in step 12.

  11. Repeat steps 7 and 8 to return to the READY prompt.

  12. Use m65 tool to start jtagflash.prg in C64 mode. It is also possible to start jtagflash.prg from a D81 image.

    1. Download jtagflash.prg (Discord link, Sept 22)

    2. m65 --device <YOURDEV> --c64mode --run jtagflash.prg
      Note: you must specify the device, because the autodiscovery will reset the JTAG!

  13. Press Return at the three jtagflash prompts.

  14. Select the COR file you put on your SD card (we used R3RC1.COR above).

  15. Wait for flashing to complete.

  16. Turn off your MEGA65. Set DIP switch 3 to OFF.

The test core is now in slot 0. Next in the test procedure would be booting the system into MEGAFLASH by holding NO-SCROLL and then powering on the system. There you can flash slot 1 with the same core you just did put into slot 0.

After this you can proceed with testing the internals (like onboarding, fdisk, and configure) and any other software you like.