1.2MB Floppy Drive  (250-4050)     Installation         Faxback Doc. # 5354

This drive is supported on the Tandy 3000 and 4000 series machines.

INTRODUCTION

Adding a second floppy disk drive to your computer significantly increases
the amount of disk storage in your computer.

We recommend that you have the second disk drive installed by the service
technicians at your Radio Shack Service Center. Doing so not only ensures
expert installation, but also enables the technicians to quickly check to be
sure all the equipment is functioning properly.

If, however, you do decide to install to install the drive yourself, follow
the steps detailed here exactly.

INSTALLATION

1. Caution should be exercised in low humidity environments to prevent damage
   to electronic parts by static electricity being discharged through them.
   (Discharge any built-up static electricity by touching a grounded metal
   object before proceeding further.)

2. WARNING: Turn off all equipment. Turn the power off and disconnect the
   power cord from the back of the computer. If the computer is on, you could
   damage the central processing unit, as well as your second disk drive.

Before proceeding, be sure your kit contains the disk drive, 4 drive
installation screws and 4 grommets.

If the drive is a Mitsubishi Model 4854 be sure that HC, DC, MM, DS1, RR, UD,
SB, TD and 11H on the drive servo/logic board are jumpered.

If the drive is a Mitsubishi Model 504A-347UA be sure that DC, MM, DS1, RR,
SB, and TD on the drive servo/logic board are jumpered.

If the drive is a Mitsubishi Model 504B-347UA be sure that DC, MM, DS1, SB,
and TD on the drive servo/logic board are jumpered.

Also be sure that the Termination resistor pack has been removed.

3. Remove the screws from the back panel of the main unit. Remove the cover
   by sliding it toward the front of the unit, parallel to the computer. Your
   computer owner's manual contains illustrations on removing the cover.

4. If the unit has a plastic air shield that covers the drives, flip it up so
   you can see the drive support (that holds the drives.)

NOTE: A 1.2 Meg. floppy disk drive must always be in the top of the drive
support.

5. Next, locate the empty holes one each side of the drive support. Insert a
   grommet into each hole. See Figure 1.

6. Carefully slide the second disk drive into the slot directly below the
   upper drive. Do not let the drives slide against each other as this could
   damage some components of the drive. Be sure the second disk drive's light
   and door latch are on the same side as they are on the upper disk drive.

7. Align the 2 holes on each side of the drive with the holes in the drive
   support.

8. Insert a screw in each hole and tighten it slightly.

9. Tighten the screws completely.

10. Find the 34-pin ribbon cable that is attached to the other floppy disk
    drive. Connect the empty connector on this cable to the card edge on the
    second disk drive. Do not twist the cable. The cable is keyed so you can
    connect it only one way. If you have a hard disk installed, be sure this
    cable is attached to connector J5 on the Hard Disk Controller board.

11. Next, connect the 4-pin power connector to the connector beside the card
    edge. This connector is keyed so you can connect it only one way.

12. If the unit is equipped with a plastic air shield, flip it to its original
    position.

13. Remove the plastic panel that covers the drive opening in the case. To do
    this, remove the screws holding the panel. Place both your thumbs on the
    outside of the panel and push in evenly. The cover should pop out. Store
    the panel and parts for future use.

14. Before replacing the main unit's cover, check all connections and be sure
    all screws are tightened.

15. If the unit has a fan filter, slide it out of the retainers.

16. Replace the main unit's cover and its screws.

17. If the unit has a fan filter, slide it into the computer from the bottom.

18. Carefully remove the shipping card from the drive slot.

NOTE: SETUP must be run before you can use your new disk drive. See your
Computer Installation and Operation Manual or instructions on how to use
SETUP.

You can then use the new disk drive on your computer. See your operating
system manual or your application manual for instructions on using data
diskettes.

(css 07/30/93)