51Chapter B - Hardware InstallationB.5 Installing the GDT controllerStep 1Switch off the PCI computer system and remove all cables (first of all the power supply).Step 2Following the instructions of the computer manual, open the case of the PCI computer, sothat you have easy access to the PCI expansion slots.Step 3Select a free PCI bus-master slot and remove the metal bracket, following the instructionsin your PCI computer manual. It is essential that the GDT controller be plugged into a bus-master slot (it will NOT work in a slave or non-bus-master slot). Some mother boards haveonly 1 bus-master slot.Make sure that the selected slot has a sufficiently cooling airflow. Permanent overheatingof electronic devices decreases their life time drastically.Step 4Channel A of the GDT controller has an internal and an external SCSI connector. If you wishto connect SCSI devices to the internal as well as to the external SCSI connec tor of channelA, disable the SCSI-bus termination of channel A by means of the GDTSETUP pro gram (seelater in this chapter). The SCSI-bus termination of the different SCSI channels of your GDTcontroller can be enabled or disabled through software-switches within the central utilityprogram GDTSETUP. When changing the SCSI-bus termination, the GDT contro ller can re-main in the computer.Step 5Push the GDT controller firmly into the correct PCI bus-master slot. Make sure that the co n-troller fits tightly into it, and that the external SCSI/FAST-SCSI connector sticks out of thecomputer case. Now, fix the GDT controller by tightening the screw of its bracket.Step 6To connect internal SCSI devices, use the internal SCSI connectors of the GDT controller (1,2, 3, or 5). You need 50-pin or 68-pin SCSI flat ribbon cables with appropriate connectors.Please verify that the coloured core of the SCSI flat ribbon cable connects PIN1 of the GDTSCSI connector to PIN1 of the SCSI device. To connect an external SCSI device, an externalround cable is needed. Please make sure that the total length does not exceed the limitswhich are determined by mode and transfer rate. Regardless of whether the SCSI devicesare connected to the internal or the external SCSI connectors of the GDT controller, youshould only use cables of highest quality in order to ensure an interference-free datatransfer. Double-check that no other SCSI device has its SCSI-ID set to 7, as this is theSCSI-ID of the GDT controller (= SCSI IDentification number, assuming values between0 and 7). If necessary, the ID of the GDT SCSI/FAST-SCSI channels can be changed with theGDTSETUP program (see later in this chapter). The SCSI-ID can be chosen directly on theSCSI device by setting DIP switches or jumpers (please refer to the manual of the SCSI d e-vice). Furthermore, all SCSI devices connected to a given SCSI/FAST-SCSI channel musthave different SCSI-IDs. Additionally, it is important that the SCSI terminators are re-moved or switched off when more than one SCSI device is operated together with the GDTcontroller. Only the last and the first participant of a SCSI channel (i.e. the two ends) mayhave SCSI terminators whereas all other participants on the SCSI bus must have their te r-minators removed or - if possible - switched off. The jumpers TP (= terminator power ) onthe GDT controller are usually set. This setting may only be modified if the terminatorpower on the SCSI cable is supplied by another SCSI device. The terminator power line on
