User's Guide
Interfaces C-13
Table C-2. Serial Pin Assignments––continued
Pin Signal Source Printer Usage
9 - 10 Not connected
11 DTR Printer Same as signal on pin 20, except
polarity of signal is user-selectable
(signal present when JP1 jumper on
logic board is on pins 2/3)
12 - 19 Not connected
20 DTR Printer Goes low when printer buffer is
almost full; returns high when buffer
can hold more data (when DTR hand-
shake is turned off, this signal remains
high at all times)
21 - 24 Not connected
25 DTR– Printer Same as signal on pin 20, except
polarity of signal is user-selectable
(signal present when JP1 jumper on
logic board is on pins 1/2)
User's Guide
Interfaces C-13
Table C-2. Serial Pin Assignments––continued
Pin Signal Source Printer Usage
9 - 10 Not connected
11 DTR Printer Same as signal on pin 20, except
polarity of signal is user-selectable
(signal present when JP1 jumper on
logic board is on pins 2/3)
12 - 19 Not connected
20 DTR Printer Goes low when printer buffer is
almost full; returns high when buffer
can hold more data (when DTR hand-
shake is turned off, this signal remains
high at all times)
21 - 24 Not connected
25 DTR– Printer Same as signal on pin 20, except
polarity of signal is user-selectable
(signal present when JP1 jumper on
logic board is on pins 1/2)