This function is exactly the same as _NAME$.
If the specified index is greater than the maximum name table entry, a bad parameter error is returned. If it is smaller than 0, an error may be generated, or junk may be returned.
A file called TurboFix_bin can be used to allow BASIC_NAME$ to access the Minerva MultiBASIC and SMS SBASIC name tables. Some early versions of TurboFix_bin have bugs in it. Beware that not all versions of this file supports SMS SBASICs.