ASM

DISK I/O

Implement PBXGetVolInfo

From looking at the "Files.p" include file provided by Apple (and using MacsBug to disassemble the hex codes), it looks like the parameter block pointer should be put into register A0 rather than pushed onto the stack, and likewise the result code is taken directly from register D0 rather than being pulled off the stack. Also, PBXGetVolInfo seems to use trap numbers A060 (for sync calls) or A460 (for async calls), rather than A260.

Try this:

LOCAL FN PBXGetVolInfo(pbPtr&, async)
  DIM OSErr
  LONG IF async
    ` movea.l ^pbPtr&,a0
    ` moveq #12,d0
    ` dc.w $A460
    ` move.w d0,^OSErr
  XELSE
    ` movea.l ^pbPtr&,a0
    ` moveq #12,d0
    ` dc.w $A060
    ` move.w d0,^OSErr
  END IF
END FN = OSErr

LOCAL FN GetVolumeInformation(volumeIndex%)
  DIM oserr%,pbPtr&
  DIM VolName$
  DIM paramBlock.80

  pbPtr& = @paramblock
  DEF BLOCKFILL(pbPtr&,80,0)

  pbPtr&.myioCompletion& = 0
  pbPtr&.myioResult% = 0
  pbPtr&.myioNamePtr& = @VolName$
  pbPtr&.myioVRefNum% = 0
  pbPtr&.myioXVersion& = 0
  pbPtr&.myioVolIndex% = volumeIndex%
  oserr% = FN PBXGetVolInfo(pbPtr&,0)
END FN