720K Floppy Drive  (250-1065)     Installation          Faxback Doc. # 5144

NOTE: This 3 1/2" drive can be installed in Tandy 1000 computers other than 
the 1000 HX by using our 3 1/2" to 5 1/4" disk drive adapter (250-1066). This
adapter provides a 3 1/2" drive housing to fit into a standard 5 1/4" drive 
opening. Mounting requirements will vary from the instructions provided in 
this manual. (The adapter comes with a simple instruction sheet.)

Four extra screws are provided with the disk drive kit. Use them when
installing 250-1065 in 250-1066.

NOTE: On the right side of the drive cabinet, toward the rear, there is a four
position switch. This is the drive select switch. As supplied, it is set for
Drive B. If you are installing this drive to be used for other than B, set the
switch accordingly. The rear-most setting is A and the front-most setting is
D.

INTRODUCTION

Adding an additional disk drive to your computer significantly increases the
amount of disk storage available in the computer.

The internal 3 1/2" disk drive should be installed by the service technician
at your local Radio Shack Service Center. Doing so not only ensures expert
installation, but also enables the technicians to quickly check to be sure the
equipment is functioning properly. However, if you decide to install the disk
drive yourself, please follow these instructions carefully.

Removing the Option Cover and Option Boards in the 1000 HX

1. Remove the option cover of the 1000 HX by pushing down on the top of the
   option cover and sliding it back and off the unit.

2. Unplug any cables to the option board(s). Remove the screws holding the
   option board(s) in place. Remove any option boards in the unit by
   unplugging them from the main board at the bottom of the unit.

Removing the Top Cover of the 1000 HX

1. Locate and remove the two screws securing the top cover in the option bay
   of the 1000 HX.

2. Place the computer upside down on a soft surface to avoid scratching the
   case.

3. Remove the nine screws from the bottom of the unit that secure the tip
   cover to the unit.

NOTE: Be sure to take note screw legends pictured on the bottom of the
computer.

4. Hold the case top and bottom together and turn the unit upright. Remove the
   top cover from the unit.

Removing the Disk Drive Mounting Assembly

1. Locate and remove the two screws at the back of the disk drive mounting
   assembly.

2. Lift up the back of the disk drive mounting assembly and disconnect the
   interface cable from the main logic board.

3. Remove the disk drive mounting assembly from the unit by lifting up the
   back and allowing the lip in the front of the assembly to exit the slot in
   which it is installed.

Installing the Second 3 1/2" Disk Drive

1. Remove the two screws from the right side of the disk drive mounting
   assembly.

2. Remove the tape holding the interface cable to the disk drive mounting
   assembly.

3. Insert the second disk drive into the space beside the existing drive in
   the disk drive mounting assembly.

4. Attach the disk drive interface cable connector to the back of the new disk
   drive.

5. Secure the disk drive to the disk drive mounting assembly with the two
   screws previously removed from the mounting assembly.

Re-installing the Disk Drive Mounting Assembly in the System Unit

1. Slip the lip at the front end of the disk drive mounting assembly into the
   slot in the bottom of the unit.

2. Plug the disk drive interface cable into the main logic board. Be sure that
   the cable is oriented properly and that the pins line up before applying
   pressure to the connector.

3. Let the disk drive mounting assembly rotate back into position being sure
   that the screws line up with the holes in the bottom of the unit.

4. Replace and tighten screws.

Re-assembling the System Unit

NOTE: When re-assembling the case, be careful not to over tighten the screws.

1. Place the case top upside down. Remove the second disk drive slot cover by
   removing the screw holding it in place.

2. Replace the top cover being sure that it is oriented properly on to the
   bottom of the system unit.

3. Replace and secure the two screws in the option board area.

4. Holding the top and bottom case parts together turn the computer upside 
   down and replace the nine screws. Pay particular attention to the screw 
   legends near each hole. The legend indicates the length of the screw.

5. Replace any option boards that were removed from the system.

6. Replace the option cover by sliding it forward until it snaps into place.

(abo-07/30/93)