For these transfers, users must remember to set the ProDOS prefix (in this case, volume name) to the prefix of the disk to which they want to send files. The ProDOS prefix defaults to the prefix of the startup disk (/USERS.DISK in this case).
At the beginning of the transfer, the system checks for the correct type of disk (ProDOS or DOS 3.3) and the prefix of the ProDOS disk; if you've
forgotten to change the profix, you will receive the message "No Room on Volume" (namely, /USERS.DISK).
Select option "P" from the CONVERT main menu, change the prefix, and all will be fine.
A Tip: Writing the volume name on the label of each of your ProDOS disks will help you to remember that you must provide CONVERT with the disk's prefix.