I've added support to the Retrode firmware to read XBAND Modem units for both Sega and SFC/SNES.
The functionality is now available in FW v0.24a (or higher).
Keep in mind most units will have garbage SRAM data due to a dead internal battery.
If anyone is lucky to dump valid SRAM data off their unit, then I'd love to get a copy of the file. Send me a link by PM.
Take Care!