List, I finally got around to cutting some Linux code to handle the RX50 BRU sets. Since the disks date from 1986, I prefer to work with images. Basically, you extract BACKUP.SYS files from the each of the set of disks. For sake of simplicity, rename the BACKUP.SYS files 1 2 3 4... The run
brudump dest-dir 1 2 3 4 5 6 7.. Brudump checks the backup sequence and creates the files from the backup and stashes them in dest-dir. Linux x86_64 Debian 5-10-179 was used, but should run well on most recent distros. If you need this, let me know. Cheers, Chuck