# File test/backup/DSK.rb, line 55
        def    is_dos33?(sector_order)
                #currently ignores sector order
                # VTOC is at offset 0x11000
                # bytes 1 & 2 are a track number, sector number and DOS version number
    # byte 27  is maximum number of track/sector pairs which will fit in one file track/sector list sector (122 for 256 byte sectors)
    # 35    number of sectors per track (16)
                # see if these are reasonable values
    vtoc_sector=get_sector(0x11,0)
                (vtoc_sector[01]<=34) && (vtoc_sector[02]<=15) && (vtoc_sector[0x27]==0x7A) && (vtoc_sector[0x35]==0x10)
        end