Disk for HP 9825B

I have a lovely HP 9825B desktop "calc-puter," the "T" version which includes a number of ROMs that would have come on a cartridge in the earlier models. There are a number of ROM carts and interfaces on ebay for the 9825s, among them the "98217A Flexible Disk Drive" module and the 98034A HPIB interface. My question is: is the latter interface, along with the General and Extended I/O ROMs already built into the 9825B, sufficient to talk to HPIB floppy drives? Or do I need the 98217A, or some other ROM, to add the disk routines to HPL? The 98217A says it's specifically for the 9885M 8" disk drive. I don't know if it has other applications or not. I don't have a 9885M or the interface module that would be required. Thanks for any clues... -j