Radio Shack TRS-80 PC-3 Owner's Manual page 82

3. Place the Computer on the Printer/Cassette Interface shown in Fig. 19.
4. Lay the Computer down flat.
5. Gently slide the Computer to the left so that the pins on the Printer/Cassette Interface are inserted into the plug on the
Computer.
DO NOT FORCE the Computer and Printer/Cassette Interface together. If the two parts do not mate easily, STOP and
check to see that the parts are correctly aligned.
Figure 19.
82
Figure 20.