IBM 5150/5155/5160 - Formatting a 720K diskette
The 5150 BIOS, the 5155 BIOS, and the 1982 dated revisions of the 5160 BIOS, have no built-in support for 720K diskettes.
However, in machines fitted with those BIOS', if you replace the 360K floppy drive with a 'standard' 1.44M drive, you will discover that the 5150/5155/5160 will boot/read/write 720K diskettes.
The one operation that fails is the format of a 720K diskette. Either the diskette formats as 360K, or error messages such as "Parameters not supported" or "Invalid parameter" are seen.
In such cases, use of one of the following three options will enable a 720K diskette to be formatted (as 720K).
Of course, another option is to format the 720K diskette via Windows on your modern computer. Click here for details.
OPTION 1: DRIVER.SYS
See here.
OPTION 2: SETBPB35.EXE
Requirement: DOS 3.2 or higher.
First, use SETBPB35.EXE
For example, if your B: drive is a 720K 3.5" diskette drive, use:
C:> SETBPB35 B
Once done, you can then format 720K diskettes in B:
Download SETBPB35.EXE from here. (setbp.zip)
OPTION 3: DRIVPARM
An example is in revision 2 of Microsoft article Q75131 - at here.
Examples are also on the Internet.
The Internet provides examples of how to overcome the DRIVPARM problem in DOS 3.3