HCL - Hardware Compatibility List
that just means that a specific model had been tested by Symantec against a specific version of Backup Exec
As long as the manufacturer's Windows drivers allow NTBackup to see and access the hardware, BackupExec should be able to also. When you run the driver setup, just tell it to use existing drivers
If you run hardware that is not on the list and run into problems, then you have a harder time getting Symantec to help you. But since v9.1 has been End-Of-Life for a year, that is a moot point