BlueSCSI_Ultra_2026-04-27_cd0e84b.uf2 causes unknown USB device in Windows

[efpob]

New BlueSCSi Ultra

Came with BlueSCSI_Ultra_2026-03-01_d4a38955.uf2
Entered BOOTSEL mode and dropped BlueSCSI_Ultra_2026-04-27_cd0e84b.uf2
After reboot, device manager in Windows shows
"Unknown USB Device (Device Descriptor Request Failed)"

Reflashing to BlueSCSI_Ultra_2026-03-01_d4a38955.uf2 did not recover the device
Needed to obtain a compatible nuke_flash.uf2, then reflashing with BlueSCSI_Ultra_2026-03-01_d4a38955.uf2 recovered the device

[erichelgeson]

I'm unable to reproduce - here's me booting 2026.03.01 fine then rebooting into the uf2 booloader and flashing the 2026.04.27 release. fresh downloads of both files from github.

There is 1 USB device:
Bus 001 Device 011: ID 1209:2023 Generic BlueSCSI

Note if you are in USB-MSC mode (by having the bluescsi booted while connected to a PC) it will show the SD card as a USB drive. I do not have a Windows PC to test but on Linux/Mac it seems to be fine.

Platform: BlueSCSI Ultra (Narrow)
FW Version: 2026.03.01-rel Mar  1 2026 15:12:57
Flash chip size: 16384 kB
Clocking to standard I2S-compatible base speed
Reclocking with these settings are compatible with CD audio playback
Initial Clock set to 150MHz
Reclocking the MCU to 155MHz
Setting the SDIO clock to 26MHz
After reclocking, system reports clock set to 155MHz
BlueSCSI CD Audio enabled - requires DAC
Reclocking with these settings are compatible with CD audio playback
Initial Clock set to 155MHz
Reclocking the MCU to 155MHz
Setting the SDIO clock to 26MHz
After reclocking, system reports clock set to 155MHz
RM2 not found, upclocking
Reclocking with these settings are compatible with CD audio playback
Initial Clock set to 155MHz
Reclocking the MCU to 155MHz
Setting the SDIO clock to 26MHz
After reclocking, system reports clock set to 155MHz
SD Config Result: 0x3F
SDIO 1.8v High Speed, Mode D
 
=== SD Card Info ===
SD card detected, exFAT volume size: 122208 MB
SD Name: GD2S5, MID: 0x1B, OID: 0x53 0x4D
-- EnableUSBMassStorage = No
[2579ms] -- Debug = Yes
[2581ms] 
[2581ms] === Global Config ===
[2582ms] Reading configuration from bluescsi.ini
[2618ms] -- EnableUSBMassStorage = No
[2620ms] 
[2620ms] === Finding images ===
[2700ms] DBG == ID 3 optical image directory 'CD3' ==
[2726ms] == Opening 'CD3/Hard Disk Toolkit.toast' for ID 3
[2729ms] DBG ---- Image file is contiguous, SD card sectors 2454272 to 2605215
[2729ms] ---- Configuring as CD-ROM drive
[2729ms] DBG ---- Read prefetch enabled: 8192 bytes
[2833ms] === Finding images in / ===
[2854ms] == Opening /HD0_Q700.hda for ID:0 LUN:0
[2854ms] DBG ---- Image file is contiguous, SD card sectors 103424 to 1127423
[2854ms] ---- Configuring as disk drive
[2855ms] DBG ---- Geometry set from defaults: SectorsPerTrack=63 HeadsPerCylinder=255 total sectors 1024000 (not divisible)
[2856ms] DBG ---- Read prefetch enabled: 8192 bytes
[2868ms] 
[2868ms] == Platform supports ROM drive up to 15136 kB
[2868ms] DBG ---- ROM drive image not detected
[2868ms]  
[2868ms] === Configured SCSI Devices ===
[2868ms] ID: 0, BlockSize: 512, Type: Fixed, Quirks: Apple, Size: 512000kB
[2868ms] ID: 3, BlockSize: 2048, Type: Optical, Quirks: Apple, Size: 75472kB, Removable
[3219ms] 
[3292ms] Clock set to: 155MHz
[3292ms] Initialization complete!
[3292ms] Disabling status LED
[3319ms] INFO: Pico Voltage: 3.280V.
[12653ms] Basic reboot requested, press 'y' to engage or any key to clear
[12913ms] Boot into uf2 bootloader requested, press 'y' to engage or any key to clear
Platform: BlueSCSI Ultra (Narrow)
FW Version: 2026.04.27-rel Apr 28 2026 00:36:16
Flash chip size: 16384 kB
=== Bootloader Log ===
[4ms] Bootloader version: Apr 28 2026 00:36:01 BlueSCSI Ultra
[4ms] Looking for firmware: BlueSCSI_Ultra*.bin
[13ms] Bootloader continuing to main firmware
=== End Bootloader Log ===
Clocking to standard I2S-compatible base speed
Reclocking with these settings are compatible with CD audio playback
Initial Clock set to 150MHz
Reclocking the MCU to 155MHz
Setting the SDIO clock to 26MHz
After reclocking, system reports clock set to 155MHz
BlueSCSI CD Audio enabled - requires DAC
Reclocking with these settings are compatible with CD audio playback
Initial Clock set to 155MHz
Reclocking the MCU to 155MHz
Setting the SDIO clock to 26MHz
After reclocking, system reports clock set to 155MHz
RM2 not found, upclocking
Reclocking with these settings are compatible with CD audio playback
Initial Clock set to 155MHz
Reclocking the MCU to 155MHz
Setting the SDIO clock to 26MHz
After reclocking, system reports clock set to 155MHz
SD Config Result: 0x3F
SDIO 1.8v High Speed, Mode D
 
=== SD Card Info ===
SD card detected, exFAT volume size: 122208 MB
SD Name: GD2S5, MID: 0x1B (Samsung), OID: "SM" (0x53 0x4D)
-- EnableUSBMassStorage = No
[2540ms] -- Debug = Yes
[2542ms] 
[2542ms] === Global Config ===
[2543ms] Reading configuration from bluescsi.ini
[2585ms] -- EnableUSBMassStorage = No
[2588ms] 
[2588ms] === Finding images ===
[2680ms] DBG == ID 3 optical image directory 'CD3' ==
[2710ms] == Opening 'CD3/Hard Disk Toolkit.toast' for ID 3
[2714ms] DBG ---- Image file is contiguous, SD card sectors 2454272 to 2605215
[2714ms] ---- Configuring as CD-ROM drive
[2714ms] DBG ---- Read prefetch enabled: 8192 bytes
[2834ms] === Finding images in / ===
[2858ms] == Opening /HD0_Q700.hda for ID:0 LUN:0
[2858ms] DBG ---- Image file is contiguous, SD card sectors 103424 to 1127423
[2858ms] ---- Configuring as disk drive
[2858ms] DBG ---- Geometry set from defaults: SectorsPerTrack=63 HeadsPerCylinder=255 total sectors 1024000 (not divisible)
[2859ms] DBG ---- Read prefetch enabled: 8192 bytes
[2872ms] 
[2872ms] == Platform supports ROM drive up to 12284 kB
[2872ms] DBG ---- ROM drive image not detected
[2872ms]  
[2872ms] === Configured SCSI Devices ===
[2872ms] ID: 0, BlockSize: 512, Type: Fixed, Quirks: Apple, Size: 512000kB
[2872ms] ID: 3, BlockSize: 2048, Type: Optical, Quirks: Apple, Size: 75472kB, Removable
[3224ms] 
[3278ms] Clock set to: 155MHz
[3278ms] Initialization complete!
[3278ms] Disabling status LED
[3310ms] INFO: Pico Voltage: 3.276V.

[efpob]

I initially didn't have the SD-card inserted when I flashed from BOOTSEL

I flashed with an SD-card inserted, and it worked :)

[erichelgeson]

Odd! The BOOTSEL UF2 bootloader is completely separate from BlueSCSI and having a SD card in (or not) shouldn't make a difference.

[efpob]

Just tested again
Removed SD card
Rebooted to BOOTSEL
Flashed uf2
Unrecognised USB device

Inserted SD card
Rebooted to BOOTSEL
Flashed uf2
BlueSCSI Narrow USB and COM6 appear

[fdanapfel]

@efpob

Just tested again Removed SD card Rebooted to BOOTSEL Flashed uf2 Unrecognised USB device

What happens if you insert the SD card at this point and reconnect the BlueSCSI?

Inserted SD card Rebooted to BOOTSEL Flashed uf2 BlueSCSI Narrow USB and COM6 appear

What happens if you remove the SD card at this point and reconnect the BlueSCSI?

[efpob]

Yep, putting the SD card back in, then reconnecting "recovered" from unknown USB device status

Removed SD card
Rebooted to BOOTSEL
Flashed nuke
Self reboot
Flashed april uf2
Unrecognised USB device
Insert SD
Reconnect BlueSCSI
BlueSCSI and COM appear