I didn't find a wiki page for scsi terminators, but since they are such a simple topic, there probably are FAQs written already. Google searches didn't turn up particularly useful info though, so there might be value in a summary.
In principle both ends of a SCSI bus need to be terminated, but there are a few exceptions: when the host controller is permanently connected at one end of the bus, it handles termination at that end. and if there are no devices on a bus, it isn't necessary to terminate it. So even though the Indigo2 manual says to leave a terminator on the external bus (1) when it isn't being used, you don't have to. The Indigo2's internal bus has termination built in and no terminator packs should ever be used.
The Indy is one of the machines where both external and internal terminators need to be used, since the same bus is connected to internal drives and the rear-panel connector. Internal terminators are usually passive, shaped like 50-pin IDC plugs, and usually pass-through, so they can be connected in between the last internal drive and the cable. This is not really ideal because the drive will be on "the wrong side" of the termination, but it worked on 5 MB/s systems. On faster systems (like the Indy) it's better to either let the drive be the terminator (check the drive's manual for how to do this), or to have the drive plugged into the cable a little way from the end, and put the terminator pack on the actual end of the cable.
External terminators are usually (but not always) not pass through, and typically active terminators are distinguished by having an LED light, which passive terminators lack. It's always better to use active termination, because it adapts to different bus lengths and device loads. The Indy should always have an external terminator, when no external devices are used (because the same bus is also for the internal devices). Some external drive boxes have switchable termination, and those could be used instead of a terminator plug if you had one connected.
In principle both ends of a SCSI bus need to be terminated, but there are a few exceptions: when the host controller is permanently connected at one end of the bus, it handles termination at that end. and if there are no devices on a bus, it isn't necessary to terminate it. So even though the Indigo2 manual says to leave a terminator on the external bus (1) when it isn't being used, you don't have to. The Indigo2's internal bus has termination built in and no terminator packs should ever be used.
The Indy is one of the machines where both external and internal terminators need to be used, since the same bus is connected to internal drives and the rear-panel connector. Internal terminators are usually passive, shaped like 50-pin IDC plugs, and usually pass-through, so they can be connected in between the last internal drive and the cable. This is not really ideal because the drive will be on "the wrong side" of the termination, but it worked on 5 MB/s systems. On faster systems (like the Indy) it's better to either let the drive be the terminator (check the drive's manual for how to do this), or to have the drive plugged into the cable a little way from the end, and put the terminator pack on the actual end of the cable.
External terminators are usually (but not always) not pass through, and typically active terminators are distinguished by having an LED light, which passive terminators lack. It's always better to use active termination, because it adapts to different bus lengths and device loads. The Indy should always have an external terminator, when no external devices are used (because the same bus is also for the internal devices). Some external drive boxes have switchable termination, and those could be used instead of a terminator plug if you had one connected.
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