Talk:11000 Series plug-in interface

The part about there being no 11000 horizontal plug-in slots is complicated. I'm not sure about the digital 11000 mainframes (i.e., 11400 and DSA600), but in the 11300, the right plug-in slot is special. The vertical signal from the plug-in in the right plug-in slot of the 11300 scopes cannot be routed to the vertical deflection plates of the CRT. However, it can be routed to the horizontal deflection plates. So in some sense, the right plug-in slot of 11300 mainframes is a horizontal slot. The right slot in 11300 scopes is sometimes called the "AUX" slot. And this leads to some potential confusion around nomenclature: In some places, the slots are referred to as "L", "R", and "A" (i.e., "AUX"). In other places, the slots are referred to as "L", "C" (i.e., "CENTER"), and "R". So "R" sometimes refers to the middle plug-in and sometimes refers to the rightmost plug-in.

Tektronix did not sell any general-purpose timebase plug-ins for the 11000 Series, so it's not clear what they expected people to do with the rightmost plug-in slot. The rightmost slot is also special (and similar to a 7000-series horizontal slot) in another aspect: The trigger output signals from the LEFT and CENTER plug-ins are routed to the RIGHT plug-in. This can be seen in the 11301 Interface Board schematic, an excerpt of which is here: Trigger signal feeds from LEFT and CENTER 11301 plug-ins to RIGHT plug-in.

As a matter of trivia, if one were to call the 11300's RIGHT slot a "horizontal" slot, then might be the only Tek scope that has a timebase part of the mainframe and also an easily swappable module.