40 MB Smartdrive (250-1046) Mounting Brackets Faxback Doc. # 3057 When installing the Smartdrive in a Tandy 1000 TL/2 or TL/3 that already has two 3.5" floppies, you need to install a mounting bracket between the 5.25" bay and the speaker. The part number to order out of National Parts is MB-0109.