ZuluSCSI RP2040 support for USB Mass Storage - access SD card contents via USB

[rabbitholecomputing]

Thanks to a firmware contribution from @zigzagjoe, ZuluSCSI RP2040 owners have some experimental/preview firmware that enables USB MASS STORAGE support for ZuluSCSI RP2040, allowing you to access the contents of the SD card via USB. As this is limited to 11Mbit/second USB 1.1 speeds, it is not fast (~700 kilobytes/sec read, ~600ish kB/sec write) but it can be extremely convenient. You can test an experimental build of it out at https://github.com/ZuluSCSI/ZuluSCSI-firmware/releases/tag/v2023.11.29-USBMassStor-BETA

This RP2040-specific firmware works equally with ZuluSCSI Mini (DB25), ZuluSCSI Compact RP2040 , ZuluSCSI Compact Homebrew kit, as well as the original full-size ZuluSCSI RP2040 desktop board, which Rabbit Hole Computing released a little over a year ago.

For questions regarding usage of this new preview functionality, please ask in the relevant Discussion thread on the ZuluSCSI-firmware GitHub page

 

[macuserman]

Yes!! This is awesome!! I’ve been waiting for this for so long. Zulu just keeps getting better.

 

[zigzagjoe]

I'm glad to contribute - it was my own laziness that gave rise to this. Down with card-swapping!
The beta for the Daynaport Pico will hopefully be ready soon too.

 

[robin-fo]

Cool! But why not also the other way round? Attach a spinning ATA/SATA harddrive to the Mac through USB instead of using the SD Card! But I fear this would be too much for that tiny uC..

 

[bigmessowires]

After reading the summary and the GitHub, I'm still a little unclear exactly what this does or how it's intended to be used. I think this is for mounting the SD card on a modern computer remotely, instead of putting the SD card into a card reader attached to the modern computer. How does it interact with SCSI emulation - can you access the SD card from USB and SCSI at the same time, or if not, how are the two interfaces prioritized?

 

[zigzagjoe]

After reading the summary and the GitHub, I'm still a little unclear exactly what this does or how it's intended to be used. I think this is for mounting the SD card on a modern computer remotely, instead of putting the SD card into a card reader attached to the modern computer. How does it interact with SCSI emulation - can you access the SD card from USB and SCSI at the same time, or if not, how are the two interfaces prioritized?

It's an alternate mode where it will act as USB storage rather than SCSI emulator. It's basically a convenience function for the use case where you often move images in/out of folders or edit the config file on the zulu, to avoid needing to pull the card out and stick it in a reader.

The UI is detailed in this post: https://github.com/ZuluSCSI/ZuluSCSI-firmware/discussions/346#discussioncomment-7736633

Basically, you get a small window to enter card window mode when power is first applied (by connecting to a computer) after which it acts normally.

 

[bigmessowires]

Thanks! I don't think that post was there yet when I looked yesterday - it explains the feature nicely. Very cool, thanks for doing this.