This trap returns information about the medium.

• All registers not shown above are not used on entry and are preserved on exit.
• The channel ID in A0 must belong either to a file on the medium or to its directory.
• The msw of D1 will contain the number of empty 512 byte sectors on the medium. The number in D1.W is the total number of sectors available.
• The buffer whose address is given in A1.L must be 10 bytes long. This will contain the medium name left justified and padded to the right with the space character ($20).

The example below shows the use of this trap. It is assumed that A0 contains the ID either of a file on the medium or of its directory. Also it is assumed that buf(A6) is the address of a 10-byte buffer.

info    moveq   #fs_mdinf,d0    ; $45
        moveq   #-1,d3          ; Timeout
        lea     buf(a6),a1      ; A 10-byte buffer
        trap    #3              ; Get the information
        tst.l   d0              ; OK? . .
        bne     error           ; . . no!