9600 Service Manual - gmecorp-usa.com

16 Workstation Control
Aux Interface PCB in the Workstation. They pass through the Aux Interface PCB to the
AT Communications PCB where they are inverted by U15 and enter DUART U27. U27
interfaces the signals to the data bus of the AT Motherboard.
The 386 AT Motherboard communicates over the data bus to DUART U27 on the AT
Communications PCB. TXDA (pin 30) and RTS (pin 29) leave DUART U27, pass
through RS232 line driver U16 and leave the AT Communications PCB at P3. They
then pass through the Aux Interface PCB, the Interconnect Cable and enter the C-Arm
at J1 on the Power Panel. They pass through the Mainframe Motherboard and enter the
Technique Processor PCB at P2.
On the older Technique Processor PCB (Assy. #876735) the signals then pass through
RS232 driver/receiver U52 and are received by serial communications controller U39 at
pins 8 (RXD) and 23 (CTS).
On the newer Technique Processor PCB (Assy. #877744) the signals then pass through
RS232 driver/receiver U52 and COM SELECT GAL U38 and are received by serial
communications controller U39 at pins 8 (RXD) and 23 (CTS).
VCR CONTROLS
Control signals for the VCRs are interfaced to the AT Motherboard via the AT
Communications PCB at P3. Refer to the Peripherals section for details.
PARALLEL PRINTER INTERFACE
The port for a parallel printer is interfaced through the AT Communications PCB at
connector P4. Refer to the Peripherals section for details.
COM 1 AND COM 2 COMMUNICATION PORTS
COM 1 and COM 2 communication ports are currently not used on the 9600 system.