PK-88 OPERATING MANUAL
APPENDIX C
C - 2
PK-88 - 153
9. Carefully replace the PK-88 top chassis and the four screws that hold it in place.
This completes the TTL Serial conversion of the PK-88. There are a few things you should be
aware of when connecting a TTL or RS-232 computer to the PK-88. The ONLY pins that should
EVER be wired in a TTL configuration are pins 1-5, 7, and 8. All other pins should be left uncon-
nected.
NOTE:
This is especially true of pin-6 which is the RS-232 DSR signal. This pin is wired
through a resistor to +10 volts and should NEVER be connected to a TTL level com-
puter under any circumstances.
Figure C-1 TTL Header Installation Diagram.